Release WildTrace strict481 public package

.gitattributes

@@ -58,3 +58,5 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 # Video files - compressed
 *.mp4 filter=lfs diff=lfs merge=lfs -text
 *.webm filter=lfs diff=lfs merge=lfs -text
+data/wildtrace_strict481.with_answers.json filter=lfs diff=lfs merge=lfs -text
+data/wildtrace_strict481.with_answers.jsonl filter=lfs diff=lfs merge=lfs -text

CHECKSUMS.sha256

@@ -0,0 +1,248 @@
+b72728a79f747e09afb3fcd643f7dbec3194f622a91eebea0623218590b53132  LICENSE
+3c1647f051121bcf3861ff2ecf81bfb4266f041ca93cbab368b723aa9c7b1064  README.md
+69077a8632a9b760d542f51fd979ac8f48c7f4785a8da28028b554eee78c26fa  corpus/adam_bede.txt
+89053a97930794a97cf842bc72042475d20c776dae82d734ffe97cb5e11ef967  corpus/alton_locke.txt
+1ca60b578d990db5324489e767603f5d71021480c24cb91750125f2ea6a2a49c  corpus/anna_karenina.txt
+60a3e06ec21a391149ab701eaed47d9d3a98c3515d9c3ed97ed5dce8bed00f06  corpus/armadale.txt
+caf2bb073b3067107228db62f162d5b5ec6dc74e9d9ca524d52947b579c948a9  corpus/armadale_full.txt
+9527e50e39c803b42e39950bd6d33f32226966f17c4d18ea38e41e980f75eebb  corpus/asya_first_love.txt
+1cecd791e591c814291af35e4de8a78f0738ad51d6686379116297fd87456b07  corpus/ayalas_angel.txt
+f1e0882322217b7ec2230c4302f6d9aacb683cd3ad2199b41ccb6771c73cf678  corpus/barchester_towers.txt
+5fef558452ad547914d5640b15240394bde7bd68667794d4805fc0dbed185adc  corpus/barnaby_rudge.txt
+9c8e40b0447e0ef6859905d9075b0d15c7b8c9c6a77b532a554488aba46a3cee  corpus/barnaby_rudge_v2.txt
+764a1982952e868913432b00a687ed3b023fd1a7da050f94b52ffdad50d1ce67  corpus/betrothed.txt
+8fe0c927d21863c22f5874a5610a095227f102b0433e2c8e98d7bbba68a98191  corpus/blazed_trail.txt
+5fa87538bc0577c74790c492b51eea516a54a9ff80a5ec10b8373e21e978341d  corpus/bleak_house.txt
+8ee679ba4500269ff40a2727ea847de88b7083563e622ba7821646c06119fe3d  corpus/camilla_burney.txt
+412b4e921353a42c1a0b530c7492f6c35a7d527b6a0bdfc3c5f3890c1b801cf8  corpus/can_you_forgive_v2.txt
+aa335a4713a4245f054a4333029a6f2a30bfa046fb00d8864c03059be1a5b2e5  corpus/castle_rackrent.txt
+7d23639acbb266b935b663300fd8a31b99b5fb62a0a1d65c7497cc21f48fecfb  corpus/challenger_rogers.txt
+f18bae0a3f6bd14239d9e724f621746a4183820c9b0b0e661d9ed042c46ce281  corpus/charles_omalley.txt
+64cc56606599a626f8d3207f6f979749dccb9fbda6a58eba5a7265644beeb6fd  corpus/charterhouse_parma.txt
+f21208e52acc458d1ae9c30e226c27cfdc7b3b833c927f3daedca1d99a7a182a  corpus/checkmate.txt
+2c48b179a9c3acc1bd8ad4256ed49fdf1c9db636cd12d8baf4ce05287d96a320  corpus/clarissa.txt
+4ef25e17a54d24c764416f1cea1a3bc08c0a5950fa2968e0238ab52beddb0f5a  corpus/coldcjk_ernvyingxiong_mixed_l6_b5c.txt
+4ed674adb864baab7b6b8376933abed312a357a6cfdb8083543a4964532e2373  corpus/coldcjk_ershi_mixed_l6_b5c.txt
+8a4420b14bd9799266ec214356be04c0af206a3ccaa1bda81125be1effba98db  corpus/coldcjk_hongtianlei_l0.txt
+0718b35c3760b340cdbcfd7e754321f7edbc84bc0539bad03596aab604039403  corpus/coldcjk_huanxi_yuanjia_l0.txt
+f52f771491e0722b77f8348a95a9550c9be1528aaf54f2b1f523ee1c6b3df7e6  corpus/coldcjk_shigongan_l6_slice_b5c.txt
+cc4f265df569a13eb4cb4dceffe8912969fff4dd5f5ae8f3386720931ed9340f  corpus/coldcjk_underused_mixed_l6_b5c.txt
+745683475ca72e3fdc6f39dfed0b2904ce54d2a3b651e1e759a1072ef240d4e8  corpus/cousin_phillis.txt
+cabf8c10d9cbf250c455c32baab3476e7a6523c84d4c0521823e6a746a491f09  corpus/crime_punishment_v2.txt
+3bb7eb37590d18812e670fe8c56d4fd77d96566cc5f1ed5b581f48624d438a33  corpus/csb_bayer.txt
+071d3236ecc09ebf0c3177d56dbe4a8363b5d65d882401aadde0346f8c928025  corpus/csb_chevron_final.txt
+e996ccc75a51bac9d6261523a693806183c8679e9f8f07aa927d9dc9dccc4d08  corpus/csb_chevron_regulatory.txt
+98d56aaa8dd236fd2f209615f917e25e002f6c31bdf18754422c9fb5bf67ff2f  corpus/csb_macondo_v1.txt
+96e087de57403891812c2af611718060c30b1f0ebfa8d9fbd9321e3b96396499  corpus/csb_macondo_v3.txt
+c18983707020c99a7475d84d33e0e7edd16f9cd2b21071257f8d50b08bedd5e4  corpus/csb_macondo_v4.txt
+63b651c548ea45ade6826d5db1da60010dbc89160f2d077935e942becf870059  corpus/csb_texas_city.txt
+5051159b018224d4d05efac93372085b7c3f4dd6ddc5e379bf6d335556b33ba0  corpus/dangkouzhi.txt
+33f42f9f77ee5057e01f746657c1fd2c3fbd4e10c759660fb8b6c0626f5add8b  corpus/daniel_deronda.txt
+682cd6436a1009b61f1a3e1d503a70735e40e6901a13d12449b987c73af5f519  corpus/david_copperfield.txt
+4a505835d8841eb643033067472f163c7f43fe849aec3e9978e437ad265dedcd  corpus/dead_souls.txt
+f1a658ef3d403a25a58ac14d9eadefb569447cb900b625db3394e80874d991b2  corpus/desperate_remedies_v2.txt
+e2b36de3b928e1b30bab913f1d1f07cdd9c03d5a57f0ad6b99143de9209bf8e3  corpus/dombey_son.txt
+5f35fbacd54e40bb021bbe88bc139b31c8cd6e4e1c950d383073747b3ec6187e  corpus/dombey_son_v2.txt
+ea8b9c791f30a038499958976309ee2f7622dcd1fc985fd8816ba977a99992d9  corpus/dona_perfecta.txt
+f20fc68a26f548cbc0c7ea33129b0d65dffb6cbd9f5d382fde64837dea445fc3  corpus/dracula.txt
+ce3f0bccb6f44fc840ea6fbe07f3061b31dcca6d2601daf39be3ee26bd39fdd0  corpus/duke_children.txt
+7f06ca811c57315c3455b4d73651cf2505050c18b73540d35c22942436e73450  corpus/dupont_belle.txt
+7c66f2539081b431be02cd8e7e6617135a2becc8c5fc040efc94eb188e0034b0  corpus/dupont_laporte.txt
+dc7a3cf23b6a8e7a6e915c392e0adba955618dac9a7a69131657ffb27f3131e8  corpus/east_lynne.txt
+b23201300562a4fe9e8838df36ba7c27f2f2bbbd7570fa004691d94aef67982f  corpus/ernvyingxiongzhuan.txt
+5586bbb69c63e17f0022b538c1458c31b02ec95c9be5ec232fe833c696ee1079  corpus/ershi_nian.txt
+91d886e2d9000bc9d1ad7270de8c13b345e3bf8348180047ffac6cc6fe1efabd  corpus/eustace_diamonds.txt
+5054c27e90aed2f638235812aa9615ef125c2f87d1f7e3e21c8f57c88c179570  corpus/eustace_diamonds_v2.txt
+d75f17fb5bae24f80a825cc69a18749c2ed29294317725515dc80edb51a50b68  corpus/evan_harrington.txt
+f85527e5069838a1150e2632854ff07091cf4e37f8914ed92557be26007e0056  corpus/evelina.txt
+e48a804baf3353d53e240143f817dbb5a236359d1eb6e16ec08e4ffc9094cb70  corpus/fanshawe.txt
+09df9a6040826ed030bba4304b0bb9cecd179b80569f1504d9d11d4cf651dbd6  corpus/far_from_madding_crowd.txt
+674d5f713ec4a4185cbac583c4b35c58e0459946a7c7e099e4d9a026a06fd477  corpus/far_madding_crowd.txt
+13dea0a1138aee0b247432b55e04811e9619f16e4520c204649c895dfd30ee7c  corpus/felix_holt.txt
+0141d8de857bd88554f84edb264cfd6b14bc65a0f899a096b8104003e37dd2f7  corpus/fixed_period.txt
+35fe9f615d6f6d797ef1ca6058cba7be4736d806a9bdf26bfdfdedef19ae38e3  corpus/framley_parsonage.txt
+676b8e9051cc07070239faa12fd8c441fd65c5703a047c62bfcddd3881453ef7  corpus/gpr_gipsy.txt
+3e8fa4b951c0bf1d922c3cd2aea151d9ce411c7d0c251ce29bcc2ff5d80cb6ce  corpus/gpr_heidelberg.txt
+66232dc7298e68947a244ba05ab807e306c569c032bbbbbac50139fdca9c3be0  corpus/gpr_heidelberg_smuggler_l5.txt
+86bdd2e11ff52edda9daab4a2354fae8837a3ab2e9dbbd90b35b2ddae1f59aa8  corpus/gpr_huguenot.txt
+a2189d8536aa8b88ab52d4c6f8b89d066d1c5db19068282f9cf01872a256ca71  corpus/gpr_huguenot_gipsy_b5b.txt
+8255d3197bca6fa7446694708586df7803e1815c980254dee85b35918728259f  corpus/gpr_huguenot_gipsy_heidelberg_b5c.txt
+869871f54ba2f2a9ed2a717ad6f7f462372c473d55d8e0a67eebfddc7a00f571  corpus/hand_ethelberta.txt
+ece24d5a68e106e879fbfcebe673d1748c6fd87b649a5187ef5d7d41c24e1682  corpus/hard_times.txt
+de4ba3d23d62aade9bae2f450ba99744a0f7acfeadbfd11dc8e3add02cb3762e  corpus/haunted_hotel.txt
+dda400b33f3a6598d442cb7bafa9189f8dc12ca23f148c9e2904bc266c9fb1e6  corpus/hayes_lemmerz.txt
+60e05e254d36ac3729eed74340c2f7e1c4682ef7b25f109c59e5ab65827580c4  corpus/heir_redclyffe.txt
+58dd7b51762d5987d2daacec10ac2c5ce2b170168f917ef853dfec9005bfc70f  corpus/helen.txt
+cc4695ca2aa1ee28040913bd78cb98d2c45ca44eff0402f75b0478749156f320  corpus/hongloumeng.txt
+11c0fd4c2d59fd448c33c608f962b4c966ee451b9e36c2f274ec8138d6ec7d47  corpus/house_seven_gables.txt
+c8e97d5a6385a6d2213efc6cee099c89891c77640f8c3d4d622adfade8ba3647  corpus/huanxi_yuanjia.txt
+797439cf089c2bc35fb19b4a0ee2b26ebc872e9aca44c8861710ae00ddb679f2  corpus/idiot.txt
+8fbf383c5cf6123493a0080b08ff648a61f67465c8b1115f1ff3c26927cd2761  corpus/imperial_sugar.txt
+4472c2a6286fc66cfecd1cc47bd4b99c8065b540c368f00352e70bb07bbb47c6  corpus/jinghuayuan.txt
+9cd4a5da25097ae12b27247fa463b5c5ccddaed9418b5a002224dc6652e8420d  corpus/johnny_ludlow_5.txt
+a6c8bfc97a8c67d6bee5003f9426e125d2b4d0bebfdbe157f550c02801fa84e4  corpus/johnny_ludlow_series_1_2_b5b.txt
+3e63b7e1d31f971b861119c112b2df7a8deb19497118c21a40764d6b65e704c9  corpus/johnny_ludlow_series_1_2_early3_b5c.txt
+12526c64bd82c0041ac2bfb85561ef652c40d040ead4b1e9bef11cbb0ff218af  corpus/johnny_ludlow_series_4_5_6_l6.txt
+cac342fe7feb282cde6ad85d244c150e75c0872edd30d87ce891db8dadb11ba6  corpus/lady_audley_secret.txt
+406ab7345cf10e1379b8e82c5ae8c4b57ecaef3dadaedabefff5398b3612c3ba  corpus/laodicean.txt
+8fe0c927d21863c22f5874a5610a095227f102b0433e2c8e98d7bbba68a98191  corpus/last_chronicle_barset.txt
+3729d683c70e24b437e9c77b6c6129ccf1d102c97e89f26189d397fb4325a234  corpus/lunheng.txt
+85a23ab6d519afae737204c7ef40056fa8240c99a58f92f787bfa8d6c20b0333  corpus/madding_crowd_v2.txt
+d7a63990cd66f24d3fc84850ead5afb530e35de1c6057693d2754a78964ffa14  corpus/mansfield_park.txt
+978b7b2900abd5fe2d9e52750a507c098f9ad6942402d318701fb6f308eb78c6  corpus/mansfield_park_v2.txt
+fdd46bca5c3ac7cbf2a041c1509af8f5868358a703d84af0d569c0dbc8482162  corpus/marion_fay.txt
+b6b2d6cf415b75f3c4ffbdf8734373f11e28f499363cb9324f0ea7f41dde8c12  corpus/mary_barton.txt
+0ec0d97813dd0799749896149fc871984539848b13ded54f0e9e6ce268b185b1  corpus/mayor_casterbridge.txt
+1c24605870ba0ce7a6871932c2dfb29318e563bfb736c886e5e6e02435ed15ac  corpus/middlemarch.txt
+3ae3fa203a9e127d12a535b8546813fa2cf6b7a7b96dac9ba1c509e5159ce3b6  corpus/mildred_arkell_vols_1_3_l4.txt
+1e62a12da4b0a6fe84f42d520365dab2fe70ed276cf36c8e54bfd802cee1f5a5  corpus/mill_on_the_floss.txt
+39b17f5dd379cb995ed0cd2c3df5bb045798645b837df033b42ef34500a5c64e  corpus/monte_cristo.txt
+c6012c77fa0d00c05db890617b745566aac42ee888a3d26c5e105eb7a2486c6f  corpus/moonstone.txt
+8dcecb113495de745e7f5b580f1bc8019352ad4443dcbf383f16a8178e2c3081  corpus/morton_intl.txt
+905f0388e7377d04f4d97fd5b7fee6b06436a7eac18d03abfafd1336fc0a4e6e  corpus/motiva.txt
+f114e444f625e8c767e0f9057dbcb26a8aec6225a05319d882f02828a16790be  corpus/mr_midshipman_easy.txt
+02119490ccf77598d98b56aaa1292c956e9288df631e24cfa68a123220a10a76  corpus/mysteries_london_v1.txt
+3acf5a747c2fe093aa15dba9b4cecfb84c96cfabb61c7408040c862fec89a0b0  corpus/mysteries_london_v2.txt
+a55c9b8cc8436c720f8945db15bbd57f122af3e91e5a850c8ce35dfcfc7618c8  corpus/mysteries_london_v3.txt
+e83a1f8fee95f906d6ea4a6b659f304284fa54fef7cdc5eae3cb24b306e7c293  corpus/mysteries_london_v4.txt
+a981e2477ff3f1feff47c37a7c06f7fcc05440273190a7021de135113dc91871  corpus/mysteries_udolpho.txt
+50144475e95d11d7ccbe0f83e81e56c61771bcb2b276bf16cb6222e9198fd6fa  corpus/mystery_edwin_drood_v2.txt
+9cc565b4b453d1c03d3a02d1361eec116225da274cf3ee748ba84e805921f0ad  corpus/new_grub_street.txt
+eae11f7ab9f57346bb313053eb0230e67f0f097b96f455fd55572f3bbce17809  corpus/newcomes.txt
+cd56d414b952c5eda440f16a434f23b2cf1a2984e22c50acbe8c7d5b6df22919  corpus/newmystery_l0_circular_staircase_20260621.txt
+ea79acfb2758fd50abafcd0b7285507983837da2a87561f408b29db9476321eb  corpus/newmystery_l4_green_leroux_lowndes_brown_20260621.txt
+455f9dd44a78023fb4000466a2c557b63b2c77176553a41e4d7bf9803b2fb2f6  corpus/nicholas_nickleby.txt
+75e2edb0ebe5863116c22dffd4921554a206b3264a9b1108b422cb279495bb47  corpus/no_name.txt
+49deb74ba5714bfd01261110394e6327b90f9f569814fc0504a142444cfadde6  corpus/northanger_abbey.txt
+9ee82e1e2b4b2151c93ca8c5af2e6bca9f6ee75d87d2627e149b11348c61fb69  corpus/northanger_abbey_v2.txt
+526e9528515658edd562bb9d76dbebc2ceded280f1d1568de61e73ad6f656ed5  corpus/not_wisely.txt
+15047c74bc2fc0324c7232d67c062463525f0bfcad7e314e175a23a6048597a2  corpus/ntsb_aar0201.txt
+4d4ae6ced04bbd244b6906ad8727c3436554564ef1a839162eb94cb695521348  corpus/ntsb_aar0604.txt
+bda40bbfbc9026cb6361f0f709eebe670930e899342e412a85a66bf4314fad6d  corpus/ntsb_aar1201.txt
+4ce9a80a25e818acc18bdf280a98a9e1cba4b64063618dbe0d9638fc61b80c5d  corpus/ntsb_aar1702.txt
+451d19e815562415c8fe5fe4ee84123b02372c6ce8f01f631b70b6736d665086  corpus/ntsb_aar1902.txt
+cfcc367895b194135dab82ceef736ea163176a7a145acd2643813178528a0165  corpus/ntsb_aar2001.txt
+a5f93bae8ffd7780b7816a2d9ae780cf6742082c29f27a677e06d79bce83b0e5  corpus/ntsb_asiana214.txt
+8738ed28f57e92708fe32a75b355221435e86fd249908c2a08cbd7a359d9466f  corpus/ntsb_carlsbad.txt
+83c72a276c669edff0ea72fc7c8cc9b19253f7a796ce7c50b5c19df01b243d07  corpus/ntsb_colgan3407.txt
+b6e749854f8e86932966573496e7e93c32f0224db9b2b15320b84f401782bb7d  corpus/ntsb_csb_accident_reports_l4a.txt
+c2c25e0ca3ad16169328d175dc948ea82406b7c94bea848fc230ca9d82508c2f  corpus/ntsb_csb_accident_reports_l6.txt
+2043d52395843903db17c6ded5a0526ca5425831a772c80578bbdf8be44e6123  corpus/ntsb_par0901.txt
+74f509a38bd2e66fecdbb92f7c5ba81d0c14eadc0fb56a77d03eb3a2f510abe0  corpus/ntsb_par1901.txt
+c68a8e527b0d98297821631655597f04fc3d764a4ffd198be03904123cbe723a  corpus/ntsb_ups1354.txt
+73679f908dc232485dfb2b3c6668d0ef9b20a8f5473734a0ca613561bd885c82  corpus/official_underused_reports_l6_b5c.txt
+3b0bfd2338b3492f5d4d7dd4698b9ee4ca40bc9798b7a1b774b6e6453c0cf96b  corpus/official_underused_reports_l6_b5c_obf.txt
+7031e5c2dd3fb6f6bb0dfdb42c1e628a4390821ba79ee95c709d23863a8023fd  corpus/old_curiosity_shop.txt
+73786d8a70fe199a203ca4b2aff47e6a5f1439fb81888f651eb5a9b27dcecfae  corpus/oliver_twist.txt
+c0c3a941247737b518bbce0d8fd79d7880a0de150a0b8c35ee42bb5548bf4eb7  corpus/omoo.txt
+e98e8acbb79ca98af7da1cafcaff66517562f6bbfbf3464314d56f0c8ed489f2  corpus/orley_farm.txt
+c11548dfabfd0bb5211bc95701b64641e70a2416b3b99b379a936896a0468951  corpus/pamela.txt
+81bdc87157baa3a443713548abf8a82a52fd541b798b3289759034c976c0aad0  corpus/pg56902_soul_scar.txt
+52a55647acda0bef6ac0e44ede81141e9a6b1314b557cc8caef191c9a150ab15  corpus/pg71729_seven_daughters.txt
+6980482785218a5a179da0c810e937895ad32c85774fa0f66672cc5ee118b917  corpus/pg72585_viaduct_murder.txt
+905458511e93c0c85f8a9b4047416be9ecf35536e468e971a95e4458f6e6974d  corpus/pg73414_adventuress.txt
+cee15c75a0877725524a22e68d2b05cd167828b316af600b7713bd65cfb612c5  corpus/pg74006_little_sweetheart.txt
+5e2456035241cc15dcad09bfbf6e04247c0e0c25669dc20183e7bb469904d00e  corpus/pg74007_her_own_way.txt
+7495ab1844df646c1b399075111374d879df42bc8fad30af0b423692a7d3f5ff  corpus/pg75157_bishop_murder.txt
+23aab948892b8c3714bd96c4e6ba143023fa3e9f37d335027babf74c092d138f  corpus/pg75383_dangerous_inheritance.txt
+68b406403964c5e353f75d95abe5d708f00946dca9247959540f4a7585a61a26  corpus/pg76634_lillians_vow.txt
+8ecc504ecda85a7fb9fb568212812dfc163f55654a232b793f358d0e3f7017f1  corpus/pg77003_with_indians_france.txt
+5cfa4fdedc281c2cd2f47da86a0140e26534a5ff765215233ba381af6053f939  corpus/pg77004_story_sun_moon_stars.txt
+2ed954b4ea6c12ea62ebb1476ffffc127dd067b092e985319a714ceaa3954e8e  corpus/pg77016_trail_deception.txt
+41a9ac4111a95bca2f97ed33e4d199e1e923356438e9f7132e83721d516202c1  corpus/pg77019_preface_morals.txt
+e1cb52593929d193a4591c51b0c9f62df7704d6b7747678ffef02695cb0d81bb  corpus/pg77069_murder_gilded_cage.txt
+72727c1d98574c61d174513eafa316da31a493b3bc0f019c63fdf855f5b85542  corpus/pg77966_spooky_hollow.txt
+900bd7b82ff77e36e4c43a63dd565a1d6f2b797f52b905651dd22a052338e9ee  corpus/pg78482_discovery_damaris.txt
+2be4004a0ba2bf98fdfc025842b0d311e40de18d5b1d18198e7c7acc80ed6520  corpus/pg_lowdownload_fiction_mystery_b5c.txt
+9d6358604d2283587bcb8f57b57d556ae177b2095ed151e20fab2c21e93b197c  corpus/pg_lowdownload_fiction_mystery_war_b5c.txt
+55d9d4ae8c08256f2c52c7a3c85bdc56c8e7b9d49646ccc0b9ee0a27d00711f8  corpus/pg_lowdownload_inheritance_adventure_l1.txt
+65f768d0ca90b30ff1f2a5744bee9176f0014cfad19f1a64ab2ad8daa3faef86  corpus/pg_lowdownload_mixed_publicdomain_b5c.txt
+bc851bd8b20404153309a17dd93d998125b4a0031bec38f78351aa66f32484c9  corpus/pg_lowdownload_mystery_detective_b5a.txt
+01ce95ef528ed64174b533bf10ca4756b6f482a67e4fb2409f2105f30f6950b8  corpus/pg_lowdownload_mystery_detective_b5b.txt
+c23226f9d531786d6f1ce41a57e6419ff2ed1b3643b36c355296e4b3cecd7a3d  corpus/pg_lowdownload_mystery_detective_b5c.txt
+ffd2c0f7281931bd4a1df2f1cf1b6b703b52f4cb4e3aaa4319820d89c89145f5  corpus/pg_lowdownload_war_science_b5a.txt
+143dbb8553e15455ba628df7a2a3ab06630d089f1be3d207a001ed07c80e53a1  corpus/pg_lowdownload_war_science_morals_b5b.txt
+c24e5e343971176a44522a10e51ba28ca6e2da443884a04527e437e883272ac8  corpus/pg_lowdownload_youth_adventure_b5a.txt
+9d47a42630e0040a09cd7b1e0eeee95f701d779690931b6c6e95821f9fc4ca96  corpus/phantom_opera.txt
+6312f0a33f4d235a64c11ddf1bcda63ae5b8adefd8a49f68319e76532ff9d7e3  corpus/phineas_finn.txt
+5ec7649fcf1bd2c7c09d90ef348a3f2dc9ae39115d50d987b14a832bbfdc4cda  corpus/phineas_redux_v2.txt
+aa43a00684ff46515bc1b9bf677d316e075d2e312a3cf09179be8350c314deb5  corpus/pierre_jean.txt
+6b9929429bcbba253f551233c887c50c4f057af1e0eec24e9ca36c5f2eab0b8c  corpus/pillars_house.txt
+966503a23bd4ad10d60b77f704707273de49f7e2b06a1f8dfa8427ec77c0d4f4  corpus/plain_tales_hills.txt
+bda642e5374a5974da480822c75ce0f0760c5d89275ea079a73f7a96d9f9843d  corpus/prime_minister.txt
+8fb293a3bf165c3049cc487be560a6254010d129bfe09f23c539762ca47e7946  corpus/puck_pooks_hill.txt
+7590189813b6e15ff5e11c9b77f43218d20d2f8d42d039906732f66163b1b503  corpus/ralph_heir.txt
+383eb8831c8bf5143c22bf1e5d371a9050f6ce1dc97078b96a0eb8b31b4f32aa  corpus/return_native.txt
+15fef065094ddcac0bdf882f7daa25f51f976022bdf41adb07c7618d502d66ee  corpus/return_of_the_native.txt
+fc7be06ca7ac11e2689d07292528c3fbeda832bc698843c49a6035be4d8bf98f  corpus/return_sherlock.txt
+6e607c7c773e8c69b1217fd7905889a62d41e0d4ee30d8d6705313b907bcd672  corpus/romola.txt
+ccf3e5ff2e2152b66d68762df292b98dc4caf0f1f7affa07b5d744785df5fefe  corpus/sanxiawuyi.txt
+5389712381624ac20f248a1c0879e820d8019446dd8e7053e5cb42f83b5d8f79  corpus/shigongan.txt
+ab99d3d34d486c8f5142b6d8c4d2bf23dbfa3a69d52403945de368fc42f4e8ca  corpus/shirley.txt
+c8b05417fb2fc55aca2d898889d0a3352313bde14a7f050069f02aa8d0ec3b31  corpus/shuangfengqiyuan.txt
+6fb519d1baa9b749135bced1f2c91c13dcdd94e19cb4e7f1962ea967d42f45f1  corpus/southworth_bride_forwoman_victor_mother_b5c.txt
+0071a2297ea9c4bdc6d14cdb64bb35fd5dd62b9a6ae5fb95cdcd510871090205  corpus/southworth_discarded_daughter.txt
+f2fe6320a838f7bb2fccba48ac8bd3c2d82090204122bab2cc0df48385aebfd6  corpus/southworth_discarded_love_forwhose_lilith_b5c.txt
+6c91d6016c8759f297c2db2d362581ccc230a343c8b9fb3e3ab092c9ada3fc1d  corpus/southworth_for_whose_sake.txt
+eb8bb2e1c215a49791d2a32e1670c4619c02fabcbb659ec7e91d149472c19f07  corpus/southworth_for_womans_love.txt
+f82f3cb8b3285957746661cce6b71e8cc8cc75acdfe48c07861efb502c08c67c  corpus/southworth_her_mothers_secret.txt
+1ec2cc5d274f4a7c8fbec53753b43c0cd226141092db38f7ceea86fe4ef58d47  corpus/southworth_ishmael.txt
+8d09361c46dfa767a229350c2beb664c62e85a94ef7ae0643fd52b7ef077e95e  corpus/southworth_ishmael_selfraised_b5b.txt
+531fca708c60451ec8737d634be7ca1fc9981077b9eb5518118532712b61270e  corpus/southworth_lilith.txt
+ca85e59339850e0d8f8f1855e44434ad8bbb5051e22dd2f5783016d84278255e  corpus/southworth_loves_bitterest_cup.txt
+2bb0356dc254eeb43f81cb3b7c34539a7aaa5147b4f02a97616f1fbcad3f8e76  corpus/southworth_self_raised.txt
+5f724fa19dfa8174ce48ad455d51cde70237740ef95e5edc3ce9503176597a83  corpus/southworth_victors_triumph.txt
+06c5eb0ed36732450812de76ceea6505a1c97bb7b3301962bd1e528f592bd3a2  corpus/t2_laboratories.txt
+f85af8b69d3abce0173634e423288f54835290196a882a68f2c03fd0805d54f6  corpus/tenant_wildfell_hall.txt
+68247989c6f1b797cbcdd98e467b9203ddfb6a1f5d52de9ce81e4aaa63c9fdad  corpus/topup_redo_slice_mysteries_london_v3_forw_r277_fix.txt
+0323b76f1e6c67e99c81cc41456f7877f2a52f419531246131eade7939972608  corpus/topup_redo_slice_ntsb_csb_accident_reports_l6_caus_r435.txt
+77f3ded338f17d1ec2733b503d8a12f730c965f9c6d2b6467cd8d24e24ed02fe  corpus/topup_redo_slice_official_underused_reports_l6_b5c_caus_r284.txt
+0496ca240963860e0aa60f2c202c0859b7453ceada5905dccbed45c4bbda0063  corpus/topup_redo_slice_pg_lowdownload_mystery_detective_b5c_forw_r411.txt
+2e4e964cb3fa13c02f2c0335e8030ef23f417f033b760a2ab801d1ec40f37801  corpus/two_on_tower.txt
+386adbdc27e3d9b6f19ece316f6e2894737c61016f609025811fbb55e5604e8c  corpus/typee.txt
+166c29780dc90c4b24a1e04dcf40250de4e52e6245358c5b89f334aa415b8b57  corpus/uncle_silas.txt
+4f6c41dab3cb224dfafdd3b25d5cbff828685ca8849ee8a14c8b597738a057a4  corpus/valperga.txt
+b5fc993d3e57047315853f6f27fea7f99fc171cf13c96f330ffb494ff577078d  corpus/vanity_fair.txt
+708aa9cc6256ab6ae5c61dc118def9eb6c12b938add4335f718226a7a8e304c3  corpus/villette.txt
+369736e304fb8dd6c36c406576532e1b872b8d05d76d3074cd2192bfeb872ecc  corpus/vivian_grey.txt
+fe2f7c48433a7a915cd3c526a51b2db0dca2c79f8986148803c610e0c2009a21  corpus/wandering_jew_books_1_10.txt
+3f0d4c54a45b77afe45e79ad83fd3bdd5c96aa2c35c0160e9cc30fcbf141606a  corpus/warden.txt
+253cf20ed9e1eceeb8e65793a3784786c7e16de061f57cafa1449ce89143840d  corpus/way_live_now.txt
+d4b6fbc8c54ae8160f6067c38cbb892fa8e0515bc31fec8c26a7c5cf760f12e3  corpus/weir_hermiston.txt
+5812f6670bd2c1d4c4ffbd6b946ab507c17c5319eeac2ba686b718ed13a23dee  corpus/west_pharma.txt
+bab86f9cea34f2d786b8cb0647640cf90d6151f6d2df17eec0eae7582b242ba3  corpus/wives_and_daughters.txt
+d6acba7c1463a690bd850eeeb04359469d29e7e965f2a9f2f7b918ff9d11f4fe  corpus/wives_daughters.txt
+9e7a3ab3c5b649fa69d5741552ff8ac8cd35411436eafcdb61df9e29ab702798  corpus/woman_in_white.txt
+810a784ccbf6f3c11bb90f7da4081865f6c6940cdf82753dd7a9cec831a9cde4  corpus/woodlanders.txt
+eb948133d7582b621626b6c9f8bbb8b0e7ace472cacda01a1f00a6f44b2b9b57  croissant.json
+0f0c5d0a595458871373197e53e1570d23ba3c0cca52a4e274353a97280f4f65  data/RDM_FINAL_FREEZE_20260621_strict481.lock.json
+56e2670226fcc11f67e990fde2fdd4efcd131f0f60a8493100e28cfbbc3f9e07  data/RDM_FINAL_FROZEN_20260621_strict481.changelog.md
+8a7e9f9f7049a3bc1176214e0d7152bdde12c9b98e8d0dcacb78d5220f4d6ec9  data/RDM_FINAL_FROZEN_20260621_strict481.gate_report.json
+e9486f67c03efaa5328dc3d3261810a7efd247250f005ab697a34afeef6a0812  data/RDM_FINAL_FROZEN_20260621_strict481.stats.json
+daee31b68456727716aa72c037587f24e50beb84d550b9b98f38a99ea9db272b  data/wildtrace_strict481.questions_only.json
+68bfa024a20399066d8c631ebb3a25bb4a9724bfc7523ec97fd9efd598263536  data/wildtrace_strict481.questions_only.jsonl
+4568f3df56613df44e585a5953002c5397f0a1728603dfaacddfa922d6da2efc  data/wildtrace_strict481.with_answers.json
+312622e7018e20048c5832dfbfabf7cd7727040865fe6f206affcdebbc0a1895  data/wildtrace_strict481.with_answers.jsonl
+27ee398cec4ace74d655fee318976fc6c104dd2347c13d11358ff1d9626d97d7  documentation/NEURIPS_RELEASE_CHECKLIST.md
+0f37435e7724723cfa15e8735ffc1ea9dddedbf30d3ab3034c043cfaf09fa9bf  eval/config.json
+fb0b7ba21a0990f1f4c23e2cc7fa09d89e6dc3f52b0be9a166ccdbabe6e30ba1  eval/run_eval.py
+ac138baa999b926d632a9d05b53770b3c0fb6faad232e774a9a30ff24f770a9d  eval/run_judge.py
+4ee0fe3be104969513592cb78d8f283a9e2c65f1b73b1822f82cfae1ef74e923  figures/degradation_curve_481.pdf
+01c79009dbe71a2d755b220da4744c928566fcb6785e8bfa4c80c34089e33f5b  figures/degradation_curve_481.png
+eb1f7abbbedff2f497a41565e4b564c6c4c7fed10bfc5b73c03ca7185d5968ec  figures/degradation_curve_481_per_paradigm.pdf
+e4e163230fa8554ab866f07c0c9daad6689f32663631e10b506ea6b8d87632b5  figures/degradation_curve_481_per_paradigm.png
+5a5a103243a19a6efb2b9e8e70f46f4e4e23de8100d40af976fd84c5b89a4b11  metadata/corpora_manifest.csv
+590a44718be7d192d3ea04c7d3e359c82dc89637fb62b3c7f1153a9c874a10a7  metadata/corpora_manifest.json
+8e77c265ad3e1e5bfe663e3fc5aec263034e2d1ffacfeda6750713ccdbb3b53a  metadata/dataset_stats.json
+a0a716e21544630f161ab1845e43abc02bb39a0eca004f3af336e4f9e72aad82  metadata/schema.json
+ad9d9cc8b4054aef88da98623661c78c33d2a8afb0fa2628fdb1301ee41543e1  methodology/EVAL_PROTOCOL.md
+85a57e53de480ccaae92fbe4d38b58d73b2c00e1c5a87c934e23f131da405731  methodology/cross_judge_calibration.md
+020c02fcc2aea3786a9fe85492c5f1a445777f5a68868135ebd57204330bd583  results/compute_profile_20260615.json
+f40d4af128056d6f730ba6752f285f3871af4c5c9ded2298bd18cee06aca85c7  results/degradation_curve_481_20260621.json
+fd6d6fd4edce773dbb9f7638a10d22bbd91e78b43a3934e7260c02a82f5b999d  results/leaderboard_matched_481_20260621.json
+7404ed4a9e41e13911402367f39ab1b0422acae012f1d1891c0a070458c3d145  results/multijudge_scores_strict481.json
+64e6cca4ee44830d2479747acf2dad387c2c16dc342d61f5311bfb7c4f1d2f61  results/reference_scores.json
+ffc50f8133166673372ae589278646cb565546724148e8d8f4dd9dc629f7b200  results/reference_scores_per_judge.json
+e295d0bc0096b683ad258609d6bdeb4db19364745ef701a0b3088efec009b268  results/scores_matrix_strict481.json
+9216f159b8475a29f5ef7f797e97c511cc6185ee80985ad863df42e1cb80c214  upload_to_hf.py
+bbc809f06ee9dab93d9b98e83919a3456b7e3619a991ae75e4f5fefddeabbc6d  upload_to_hf.sh

LICENSE

@@ -0,0 +1,11 @@
+WildTrace strict481 license notice
+
+Benchmark annotations, questions, rubrics, metadata, and release scripts are
+licensed under the Creative Commons Attribution 4.0 International License
+(CC BY 4.0): https://creativecommons.org/licenses/by/4.0/
+
+Source documents retain their original public-domain, public-agency, Project
+Gutenberg, or source-specific terms. The presence of a source document in this
+benchmark package does not change the original source terms. Users are
+responsible for complying with source-specific terms when redistributing,
+adapting, or using the source texts.

README.md

@@ -0,0 +1,194 @@
+---
+license: cc-by-4.0
+language:
+- en
+- zh
+size_categories:
+- n<1K
+task_categories:
+- question-answering
+- text-generation
+task_ids:
+- document-question-answering
+- open-book-qa
+tags:
+- benchmark
+- long-context
+- multi-hop-reasoning
+- source-internal-reasoning
+- evidence-withheld
+- document-qa
+- mlcroissant
+- neurips-2026
+pretty_name: WildTrace strict481
+configs:
+- config_name: with_answers
+  data_files:
+  - split: test
+    path: data/wildtrace_strict481.with_answers.jsonl
+- config_name: questions_only
+  data_files:
+  - split: test
+    path: data/wildtrace_strict481.questions_only.jsonl
+---
+
+# WildTrace strict481
+
+WildTrace is a source-internal long-context multi-hop reasoning benchmark
+built from natural evidence trails. Unlike reverse-synthetic QA, its tasks are
+mined in situ from long source documents before questions are written. The
+strict481 release contains 481 locked tasks over 214 public long-form sources,
+with full-document, evidence-withheld evaluation. The model under test receives
+only the source document and the public question; evidence spans, clue counts,
+reference answers, rubrics, and validation notes are hidden.
+
+Freeze id: `20260621_strict481_final_freeze`. Release version: `wildtrace-strict481-final-2026-06-21`. The L0--L6
+tier-by-paradigm sample floor is fully met; L7 is a three-item >1M-token stress
+probe.
+
+## Contents
+
+- `data/wildtrace_strict481.with_answers.json`: full nested benchmark artifact
+  with questions, clues, ground truth, rubrics, review/provenance, and release
+  metadata.
+- `data/wildtrace_strict481.with_answers.jsonl`: Hugging Face / Arrow-friendly
+  view of the same rows, with deeply nested audit fields serialized as JSON
+  strings.
+- `data/wildtrace_strict481.questions_only.json` and `.jsonl`: model-input
+  rows without answers/rubrics/clues.
+- `corpus/*.txt`: the 214 source documents referenced by the tasks.
+- `eval/run_eval.py`, `eval/run_judge.py`, `eval/config.json`: minimal
+  evidence-withheld evaluation and rubric-judge harness.
+- `methodology/EVAL_PROTOCOL.md`: prompt templates, generation settings,
+  context policy, judge prompt, scoring normalization, and aggregation rules.
+- `results/reference_scores.json`, `results/reference_scores_per_judge.json`,
+  `results/scores_matrix_strict481.json`, `results/multijudge_scores_strict481.json`:
+  reference score artifacts for reproducing the paper tables without rerunning
+  all model endpoints.
+- `metadata/`: schema, corpus manifest, release manifest, checksums, and
+  dataset statistics.
+- `croissant.json`: MLCommons Croissant metadata with Responsible AI fields.
+
+## Snapshot Statistics
+
+| Item | Value |
+|---|---:|
+| Tasks | 481 |
+| Source documents | 214 |
+| Languages | en: 441, zh: 40 |
+| Min estimated document tokens | 19,106 |
+| Median estimated document tokens | 302,084 |
+| Max estimated document tokens | 2,549,520 |
+
+## Evidence Geometries
+
+| Geometry | Count |
+|---|---:|
+| `abductive_inference` | 65 |
+| `causal_attribution` | 67 |
+| `comparative` | 67 |
+| `counterfactual_reasoning` | 67 |
+| `forward_chain` | 73 |
+| `intersection_query` | 71 |
+| `temporal_reconstruction` | 71 |
+
+## Context Tiers
+
+| Tier | Count |
+|---|---:|
+| `L0_<=128K` | 90 |
+| `L1_128K_181K` | 59 |
+| `L2_181K_256K` | 61 |
+| `L3_256K_362K` | 58 |
+| `L4_362K_512K` | 59 |
+| `L5_512K_724K` | 58 |
+| `L6_724K_1M` | 93 |
+| `L7_>1M` | 3 |
+
+## Source Families
+
+| Source family | Task count |
+|---|---:|
+| `cjk_literature` | 40 |
+| `en_literature` | 318 |
+| `technical_report` | 123 |
+
+## Usage
+
+Local package:
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset(
+    "json",
+    data_files="hf_release_wildtrace_strict481_20260621/data/wildtrace_strict481.with_answers.jsonl",
+    split="train",
+)
+print(ds[0]["question_id"])
+print(ds[0]["question_text"])
+```
+
+After upload to Hugging Face:
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("CinderD/wildtrace", "with_answers", split="test")
+```
+
+To evaluate a model, use `eval/run_eval.py` with `--corpus ../corpus`; the script
+constructs the exact evidence-withheld prompt from `question_text` and the full
+source document. Use `eval/run_judge.py` to score answers against the hidden
+rubric. See `methodology/EVAL_PROTOCOL.md` before reporting new results.
+
+## Scoring Denominators
+
+The paper reports both valid-response quality and all-481 zero-filled quality.
+`Scored` is the mean over valid scored responses for a route. `All481` uses all
+481 attempted tasks as the denominator and zero-fills missing, failed, and
+out-of-context rows. The `n` column in leaderboard tables is a valid-response
+count, not a dataset denominator.
+
+## Quality Assurance
+
+Each retained item is tied to source-grounded clues, a criterion-level rubric,
+and release-review metadata. The final release passed an external acceptance
+gate for paradigm validity, leave-one-out multi-hop necessity, grounding,
+uniqueness, and coherent-source constraints. Serious expansion defects were
+excluded before the strict481 freeze; minor retained rows only removed redundant
+clues without changing question text or source documents.
+
+## Responsible AI
+
+The source corpus consists of public-domain literary works, Chinese literary
+sources, and publicly available technical incident reports. Some sources mention
+injury, death, violence, or distressing events because they are faithful to the
+original public documents. WildTrace is intended for diagnostic evaluation of
+source-grounded long-context reasoning, not for deployment certification in
+legal, medical, safety-critical, financial, or investigative settings.
+
+Public release can increase benchmark contamination risk. New leaderboard claims
+should disclose whether a model may have seen the benchmark items or source
+documents during training.
+
+## License
+
+Benchmark annotations, questions, rubrics, metadata, and scripts are released
+under CC BY 4.0 unless otherwise noted. Source documents retain their original
+public-domain, public-agency, or source-specific terms. Users are responsible for
+complying with source-specific terms when redistributing or adapting source
+texts.
+
+## Citation
+
+```bibtex
+@misc{wildtrace2026,
+  title={WildTrace: Natural Evidence Trails for Source-Internal Multi-Hop Reasoning in Long Contexts},
+  author={WildTrace authors},
+  year={2026},
+  howpublished={Hugging Face dataset},
+  url={https://huggingface.co/datasets/CinderD/wildtrace},
+  note={strict481 final release, freeze 20260621_strict481_final_freeze}
+}
+```

corpus/checkmate.txt

@@ -0,0 +1,532 @@
+CAPTAINS ALL
+
+By W.W. Jacobs
+
+CAPTAINS ALL
+
+[Illustration: "Captains All."]
+
+Every sailorman grumbles about the sea, said the night-watchman,
+thoughtfully.  It's human nature to grumble, and I s'pose they keep on
+grumbling and sticking to it because there ain't much else they can do.
+There's not many shore-going berths that a sailorman is fit for, and
+those that they are--such as a night-watchman's, for instance--wants such
+a good character that there's few as are to equal it.
+
+Sometimes they get things to do ashore.  I knew one man that took up
+butchering, and 'e did very well at it till the police took him up.
+Another man I knew gave up the sea to marry a washerwoman, and they
+hadn't been married six months afore she died, and back he 'ad to go to
+sea agin, pore chap.
+
+A man who used to grumble awful about the sea was old Sam Small--a man
+I've spoke of to you before.  To hear 'im go on about the sea, arter he
+'ad spent four or five months' money in a fortnight, was 'artbreaking.
+He used to ask us wot was going to happen to 'im in his old age, and when
+we pointed out that he wouldn't be likely to 'ave any old age if he
+wasn't more careful of 'imself he used to fly into a temper and call us
+everything 'e could lay his tongue to.
+
+One time when 'e was ashore with Peter Russet and Ginger Dick he seemed
+to 'ave got it on the brain.  He started being careful of 'is money
+instead o' spending it, and three mornings running he bought a newspaper
+and read the advertisements, to see whether there was any comfortable
+berth for a strong, good-'arted man wot didn't like work.
+
+He actually went arter one situation, and, if it hadn't ha' been for
+seventy-nine other men, he said he believed he'd ha' had a good chance of
+getting it.  As it was, all 'e got was a black eye for shoving another
+man, and for a day or two he was so down-'arted that 'e was no company at
+all for the other two.
+
+For three or four days 'e went out by 'imself, and then, all of a sudden,
+Ginger Dick and Peter began to notice a great change in him.  He seemed
+to 'ave got quite cheerful and 'appy.  He answered 'em back pleasant when
+they spoke to 'im, and one night he lay in 'is bed whistling comic songs
+until Ginger and Peter Russet 'ad to get out o' bed to him.  When he
+bought a new necktie and a smart cap and washed 'imself twice in one day
+they fust began to ask each other wot was up, and then they asked him.
+
+"Up?" ses Sam; "nothing."
+
+"He's in love," ses Peter Russet.
+
+"You're a liar," ses Sam, without turning round.
+
+"He'll 'ave it bad at 'is age," ses Ginger.
+
+Sam didn't say nothing, but he kept fidgeting about as though 'e'd got
+something on his mind.  Fust he looked out o' the winder, then he 'ummed
+a tune, and at last, looking at 'em very fierce, he took a tooth-brush
+wrapped in paper out of 'is pocket and began to clean 'is teeth.
+
+"He is in love," ses Ginger, as soon as he could speak.
+
+"Or else 'e's gorn mad," ses Peter, watching 'im.  "Which is it, Sam?"
+
+Sam made believe that he couldn't answer 'im because o' the tooth-brush,
+and arter he'd finished he 'ad such a raging toothache that 'e sat in a
+corner holding 'is face and looking the pictur' o' misery.  They couldn't
+get a word out of him till they asked 'im to go out with them, and then
+he said 'e was going to bed.  Twenty minutes arterwards, when Ginger Dick
+stepped back for 'is pipe, he found he 'ad gorn.
+
+He tried the same game next night, but the other two wouldn't 'ave it,
+and they stayed in so long that at last 'e lost 'is temper, and, arter
+wondering wot Ginger's father and mother could ha' been a-thinking about,
+and saying that he believed Peter Russet 'ad been changed at birth for a
+sea-sick monkey, he put on 'is cap and went out.  Both of 'em follered
+'im sharp, but when he led 'em to a mission-hall, and actually went
+inside, they left 'im and went off on their own.
+
+They talked it over that night between themselves, and next evening they
+went out fust and hid themselves round the corner.  Ten minutes
+arterwards old Sam came out, walking as though 'e was going to catch a
+train; and smiling to think 'ow he 'ad shaken them off.  At the corner of
+Commercial Road he stopped and bought 'imself a button-hole for 'is coat,
+and Ginger was so surprised that 'e pinched Peter Russet to make sure
+that he wasn't dreaming.
+
+Old Sam walked straight on whistling, and every now and then looking down
+at 'is button-hole, until by-and-by he turned down a street on the right
+and went into a little shop.  Ginger Dick and Peter waited for 'im at the
+corner, but he was inside for so long that at last they got tired o'
+waiting and crept up and peeped through the winder.
+
+It was a little tobacconist's shop, with newspapers and penny toys and
+such-like; but, as far as Ginger could see through two rows o' pipes and
+the Police News, it was empty.  They stood there with their noses pressed
+against the glass for some time, wondering wot had 'appened to Sam, but
+by-and-by a little boy went in and then they began to 'ave an idea wot
+Sam's little game was.
+
+As the shop-bell went the door of a little parlour at the back of the
+shop opened, and a stout and uncommon good-looking woman of about forty
+came out.  Her 'ead pushed the _Police News_ out o' the way and her 'and
+came groping into the winder arter a toy.
+
+Ginger 'ad a good look at 'er out o' the corner of one eye, while he
+pretended to be looking at a tobacco-jar with the other.  As the little
+boy came out 'im and Peter Russet went in.
+
+"I want a pipe, please," he ses, smiling at 'er; "a clay pipe--one o' your
+best."  The woman handed 'im down a box to choose from, and just then
+Peter, wot 'ad been staring in at the arf-open door at a boot wot wanted
+lacing up, gave a big start and ses, "Why!  Halloa!"
+
+"Wot's the matter?" ses the woman, looking at 'im.
+
+"I'd know that foot anywhere," ses Peter, still staring at it; and the
+words was hardly out of 'is mouth afore the foot 'ad moved itself away
+and tucked itself under its chair.  "Why, that's my dear old friend Sam
+Small, ain't it?"
+
+"Do you know the captin?" ses the woman, smiling at 'im.
+
+"Cap----?" ses Peter.  "Cap----?  Oh, yes; why, he's the biggest friend
+I've got."  "'Ow strange!" ses the woman.
+
+"We've been wanting to see 'im for some time," ses Ginger.  "He was kind
+enough to lend me arf a crown the other day, and I've been wanting to pay
+'im."
+
+"Captin Small," ses the woman, pushing open the door, "here's some old
+friends o' yours."
+
+Old Sam turned 'is face round and looked at 'em, and if looks could ha'
+killed, as the saying is, they'd ha' been dead men there and then.
+
+"Oh, yes," he ses, in a choking voice; "'ow are you?"
+
+"Pretty well, thank you, captin," ses Ginger, grinning at 'im; "and 'ow's
+yourself arter all this long time?"
+
+He held out 'is hand and Sam shook it, and then shook 'ands with Peter
+Russet, who was grinning so 'ard that he couldn't speak.
+
+"These are two old friends o' mine, Mrs. Finch," ses old Sam, giving 'em
+a warning look; "Captin Dick and Captin Russet, two o' the oldest and
+best friends a man ever 'ad."
+
+"Captin Dick 'as got arf a crown for you," ses Peter Russet, still
+grinning.
+
+"There now," ses Ginger, looking vexed, "if I ain't been and forgot it;
+I've on'y got arf a sovereign."
+
+"I can give you change, sir," ses Mrs. Finch.  "P'r'aps you'd like to sit
+down for five minutes?"
+
+Ginger thanked 'er, and 'im and Peter Russet took a chair apiece in front
+o' the fire and began asking old Sam about 'is 'ealth, and wot he'd been
+doing since they saw 'im last.
+
+"Fancy your reckernizing his foot," ses Mrs. Finch, coming in with the
+change.
+
+"I'd know it anywhere," ses Peter, who was watching Ginger pretending to
+give Sam Small the 'arf-dollar, and Sam pretending in a most lifelike
+manner to take it.
+
+Ginger Dick looked round the room.  It was a comfortable little place,
+with pictures on the walls and antimacassars on all the chairs, and a row
+of pink vases on the mantelpiece.  Then 'e looked at Mrs. Finch, and
+thought wot a nice-looking woman she was.
+
+"This is nicer than being aboard ship with a crew o' nasty, troublesome
+sailormen to look arter, Captin Small," he ses.
+
+"It's wonderful the way he manages 'em," ses Peter Russet to Mrs. Finch.
+"Like a lion he is."
+
+"A roaring lion," ses Ginger, looking at Sam.  "He don't know wot fear
+is."
+
+Sam began to smile, and Mrs. Finch looked at 'im so pleased that Peter
+Russet, who 'ad been looking at 'er and the room, and thinking much the
+same way as Ginger, began to think that they was on the wrong tack.
+
+"Afore 'e got stout and old," he ses, shaking his 'ead, "there wasn't a
+smarter skipper afloat."
+
+"We all 'ave our day," ses Ginger, shaking his 'ead too.
+
+"I dessay he's good for another year or two afloat, yet," ses Peter
+Russet, considering.  "With care," ses Ginger.
+
+Old Sam was going to say something, but 'e stopped himself just in time.
+"They will 'ave their joke," he ses, turning to Mrs. Finch and trying to
+smile.  "I feel as young as ever I did."
+
+Mrs. Finch said that anybody with arf an eye could see that, and then she
+looked at a kettle that was singing on the 'ob.
+
+"I s'pose you gentlemen wouldn't care for a cup o' cocoa?" she ses,
+turning to them.
+
+Ginger Dick and Peter both said that they liked it better than anything
+else, and, arter she 'ad got out the cups and saucers and a tin o' cocoa,
+Ginger held the kettle and poured the water in the cups while she stirred
+them, and old Sam sat looking on 'elpless.
+
+"It does seem funny to see you drinking cocoa, captin," ses Ginger, as
+old Sam took his cup.
+
+"Ho!" ses Sam, firing up; "and why, if I might make so bold as to ask?"
+
+"'Cos I've generally seen you drinking something out of a bottle," ses
+Ginger.
+
+"Now, look 'ere," ses Sam, starting up and spilling some of the hot cocoa
+over 'is lap.
+
+"A ginger-beer bottle," ses Peter Russet, making faces at Ginger to keep
+quiet.
+
+"Yes, o' course, that's wot I meant," ses Ginger.
+
+Old Sam wiped the cocoa off 'is knees without saying a word, but his
+weskit kept going up and down till Peter Russet felt quite sorry for 'im.
+
+"There's nothing like it," he ses to Mrs. Finch.  "It was by sticking to
+ginger-beer and milk and such-like that Captain Small 'ad command of a
+ship afore 'e was twenty-five."
+
+"Lor'!" ses Mrs. Finch.
+
+She smiled at old Sam till Peter got uneasy agin, and began to think
+p'r'aps 'e'd been praising 'im too much.
+
+"Of course, I'm speaking of long ago now," he ses.
+
+"Years and years afore you was born, ma'am," ses Ginger.
+
+Old Sam was going to say something, but Mrs. Finch looked so pleased that
+'e thought better of it.  Some o' the cocoa 'e was drinking went the
+wrong way, and then Ginger patted 'im on the back and told 'im to be
+careful not to bring on 'is brownchitis agin.  Wot with temper and being
+afraid to speak for fear they should let Mrs. Finch know that 'e wasn't a
+captin, he could 'ardly bear 'imself, but he very near broke out when
+Peter Russet advised 'im to 'ave his weskit lined with red flannel.  They
+all stayed on till closing time, and by the time they left they 'ad made
+theirselves so pleasant that Mrs. Finch said she'd be pleased to see them
+any time they liked to look in.
+
+Sam Small waited till they 'ad turned the corner, and then he broke out
+so alarming that they could 'ardly do anything with 'im.  Twice policemen
+spoke to 'im and advised 'im to go home afore they altered their minds;
+and he 'ad to hold 'imself in and keep quiet while Ginger and Peter
+Russet took 'is arms and said they were seeing him 'ome.
+
+He started the row agin when they got in-doors, and sat up in 'is bed
+smacking 'is lips over the things he'd like to 'ave done to them if he
+could.  And then, arter saying 'ow he'd like to see Ginger boiled alive
+like a lobster, he said he knew that 'e was a noble-'arted feller who
+wouldn't try and cut an old pal out, and that it was a case of love at
+first sight on top of a tram-car.
+
+"She's too young for you," ses Ginger; "and too good-looking besides."
+
+"It's the nice little bisness he's fallen in love with, Ginger," ses
+Peter Russet.  "I'll toss you who 'as it."
+
+Ginger, who was siting on the foot o' Sam's bed, said "no" at fust, but
+arter a time he pulled out arf a dollar and spun it in the air.
+
+That was the last 'e see of it, although he 'ad Sam out o' bed and all
+the clothes stripped off of it twice.  He spent over arf an hour on his
+'ands and knees looking for it, and Sam said when he was tired of playing
+bears p'r'aps he'd go to bed and get to sleep like a Christian.
+
+They 'ad it all over agin next morning, and at last, as nobody would
+agree to keep quiet and let the others 'ave a fair chance, they made up
+their minds to let the best man win.  Ginger Dick bought a necktie that
+took all the colour out o' Sam's, and Peter Russet went in for a collar
+so big that 'e was lost in it.
+
+They all strolled into the widow's shop separate that night.  Ginger Dick
+'ad smashed his pipe and wanted another; Peter Russet wanted some
+tobacco; and old Sam Small walked in smiling, with a little silver brooch
+for 'er, that he said 'e had picked up.
+
+It was a very nice brooch, and Mrs. Finch was so pleased with it that
+Ginger and Peter sat there as mad as they could be because they 'adn't
+thought of the same thing.
+
+"Captain Small is very lucky at finding things," ses Ginger, at last.
+
+"He's got the name for it," ses Peter Russet.
+
+"It's a handy 'abit," ses Ginger; "it saves spending money.  Who did you
+give that gold bracelet to you picked up the other night, captin?" he
+ses, turning to Sam.
+
+"Gold bracelet?" ses Sam.  "I didn't pick up no gold bracelet.  Wot are
+you talking about?"
+
+"All right, captin; no offence," ses Ginger, holding up his 'and.  "I
+dreamt I saw one  on your mantelpiece, I s'pose.  P'r'aps I oughtn't to
+ha' said anything about it."
+
+Old Sam looked as though he'd like to eat 'im, especially as he noticed
+Mrs. Finch listening and pretending not to.  "Oh! that one," he ses,
+arter a bit o' hard thinking.  "Oh! I found out who it belonged to.  You
+wouldn't believe 'ow pleased they was at getting it back agin."
+
+Ginger Dick coughed and began to think as 'ow old Sam was sharper than he
+'ad given 'im credit for, but afore he could think of anything else to
+say Mrs. Finch looked at old Sam and began to talk about 'is ship, and to
+say 'ow much she should like to see over it.
+
+"I wish I could take you," ses Sam, looking at the other two out o' the
+corner of his eye, "but my ship's over at Dunkirk, in France.  I've just
+run over to London for a week or two to look round."
+
+"And mine's there too," ses Peter Russet, speaking a'most afore old Sam
+'ad finished; "side by side they lay in the harbour."
+
+"Oh, dear," ses Mrs. Finch, folding her 'ands and shaking her 'cad.  "I
+should like to go over a ship one arternoon.  I'd quite made up my mind
+to it, knowing three captins."
+
+She smiled and looked at Ginger; and Sam and Peter looked at 'im too,
+wondering whether he was going to berth his ship at Dunkirk alongside o'
+theirs.
+
+"Ah, I wish I 'ad met you a fortnight ago," ses Ginger, very sad.  "I
+gave up my ship, the High flyer, then, and I'm waiting for one my owners
+are 'aving built for me at New-castle.  They said the High flyer wasn't
+big enough for me.  She was a nice little ship, though.  I believe I've
+got 'er picture somewhere about me!"
+
+He felt in 'is pocket and pulled out a little, crumpled-up photograph of
+a ship he'd been fireman aboard of some years afore, and showed it to
+'er.
+
+"That's me standing on the bridge," he ses, pointing out a little dot
+with the stem of 'is pipe.
+
+"It's your figger," ses Mrs. Finch, straining her eyes.  "I should know
+it anywhere."
+
+"You've got wonderful eyes, ma'am," ses old Sam, choking with 'is pipe.
+
+"Anybody can see that," ses Ginger.  "They're the largest and the bluest
+I've ever seen."
+
+Mrs. Finch told 'im not to talk nonsense, but both Sam and Peter Russet
+could see 'ow pleased she was.
+
+"Truth is truth," ses Ginger.  "I'm a plain man, and I speak my mind."
+
+"Blue is my fav'rit' colour," ses old Sam, in a tender voice.  "True
+blue."
+
+Peter Russet began to feel out of it.  "I thought brown was," he ses.
+
+"Ho!" ses Sam, turning on 'im; "and why?"
+
+"I 'ad my reasons," ses Peter, nodding, and shutting 'is mouth very firm.
+
+"I thought brown was 'is fav'rit colour too," ses Ginger.  "I don't know
+why.  It's no use asking me; because if you did I couldn't tell you."
+
+"Brown's a very nice colour," ses Mrs. Finch, wondering wot was the
+matter with old Sam.
+
+"Blue," ses Ginger; "big blue eyes--they're the ones for me.  Other
+people may 'ave their blacks and their browns," he ses, looking at Sam
+and Peter Russet, "but give me blue."
+
+They went on like that all the evening, and every time the shop-bell went
+and the widow 'ad to go out to serve a customer they said in w'ispers wot
+they thought of each other; and once when she came back rather sudden
+Ginger 'ad to explain to 'er that 'e was showing Peter Russet a scratch
+on his knuckle.
+
+Ginger Dick was the fust there next night, and took 'er a little chiney
+teapot he 'ad picked up dirt cheap because it was cracked right acrost
+the middle; but, as he explained that he 'ad dropped it in hurrying to
+see 'er, she was just as pleased.  She stuck it up on the mantelpiece,
+and the things she said about Ginger's kindness and generosity made Peter
+Russet spend good money that he wanted for 'imself on a painted
+flower-pot next evening.
+
+With three men all courting 'er at the same time Mrs. Finch had 'er hands
+full, but she took to it wonderful considering.  She was so nice and kind
+to 'em all that even arter a week's 'ard work none of 'em was really
+certain which she liked best.
+
+They took to going in at odd times o' the day for tobacco and such-like.
+They used to go alone then, but they all met and did the polite to each
+other there of an evening, and then quarrelled all the way 'ome.
+
+Then all of a sudden, without any warning, Ginger Dick and Peter Russet
+left off going there.  The fust evening Sam sat expecting them every
+minute, and was so surprised that he couldn't take any advantage of it;
+but on the second, beginning by squeezing Mrs. Finch's 'and at ha'-past
+seven, he 'ad got best part of his arm round 'er waist by a quarter to
+ten.  He didn't do more that night because she told him to be'ave
+'imself, and threatened to scream if he didn't leave off.
+
+He was arf-way home afore 'e thought of the reason for Ginger Dick and
+Peter Russet giving up, and then he went along smiling to 'imself to such
+an extent that people thought 'e was mad.  He went off to sleep with the
+smile still on 'is lips, and when Peter and Ginger came in soon arter
+closing time and 'e woke up and asked them where they'd been, 'e was
+still smiling.
+
+"I didn't 'ave the pleasure o' seeing you at Mrs. Finch's to-night," he
+ses.
+
+"No," ses Ginger, very short.  "We got tired of it."
+
+"So un'ealthy sitting in that stuffy little room every evening," ses
+Peter.
+
+Old Sam put his 'ead under the bedclothes and laughed till the bed shook;
+and every now and then he'd put his 'ead out and look at Peter and Ginger
+and laugh agin till he choked.
+
+"I see 'ow it is," he ses, sitting up and wiping his eyes on the sheet.
+"Well, we cant all win."
+
+"Wot d'ye mean?" ses Ginger, very disagreeable.
+
+"She wouldn't 'ave you, Sam, thats wot I mean. And I don't wonder at
+it.  I wouldn't 'ave you if I was a gal."
+
+"You're dreaming, ses Peter Russet, sneering at 'im.
+
+"That flower-pot o' yours'll come in handy," ses Sam, thinking 'ow he 'ad
+put 'is arm round the widow's waist; "and I thank you kindly for the
+teapot, Ginger.
+
+"You don't mean to say as you've asked 'er to marry you?" ses Ginger,
+looking at Peter Russet.
+
+"Not quite; but I'm going to," ses Sam, "and I'll bet you even arf-crowns
+she ses 'yes.'"
+
+Ginger wouldn't take 'im, and no more would Peter, not even when he raised
+it to five shillings; and the vain way old Sam lay there boasting and
+talking about 'is way with the gals made 'em both feel ill.
+
+"I wouldn't 'ave her if she asked me on 'er bended knees," ses Ginger,
+holding up his 'ead.
+
+"Nor me," ses Peter.  "You're welcome to 'er, Sam.  When I think of the
+evenings I've wasted over a fat old woman I feel----"
+
+"That'll do," ses old Sam, very sharp; "that ain't the way to speak of a
+lady, even if she 'as said 'no.'"
+
+"All right, Sam," ses Ginger.  "You go in and win if you think you're so
+precious clever."
+
+Old Sam said that that was wot 'e was going to do, and he spent so much
+time next morning making 'imself look pretty that the other two could
+'ardly be civil to him.
+
+He went off a'most direckly arter breakfast, and they didn't see 'im agin
+till twelve o'clock that night.  He 'ad brought a bottle o' whisky in
+with 'im, and he was so 'appy that they see plain wot had 'appened.
+
+"She said 'yes' at two o'clock in the arternoon," ses old Sam, smiling,
+arter they had 'ad a glass apiece.  "I'd nearly done the trick at one
+o'clock, and then the shop-bell went, and I 'ad to begin all over agin.
+Still, it wasn't unpleasant."
+
+"Do you mean to tell us you've asked 'er to marry you?" ses Ginger,
+'olding out 'is glass to be filled agin.
+
+"I do," ses Sam; "but I 'ope there's no ill-feeling.  You never 'ad a
+chance, neither of you; she told me so."
+
+Ginger Dick and Peter Russet stared at each other.
+
+"She said she 'ad been in love with me all along," ses Sam, filling their
+glasses agin to cheer 'em up.  "We went out arter tea and bought the
+engagement-ring, and then she got somebody to mind the shop and we went
+to the Pagoda music-'all."
+
+"I 'ope you didn't pay much for the ring, Sam," ses Ginger, who always
+got very kind-'arted arter two or three glasses o' whisky.  "If I'd known
+you was going to be in such a hurry I might ha' told you before."
+
+"We ought to ha' done," ses Peter, shaking his 'ead.
+
+"Told me?" ses Sam, staring at 'em.  "Told me wot?"
+
+"Why me and Peter gave it up," ses Ginger; "but, o' course, p'r'aps you
+don't mind."
+
+"Mind wot?" ses Sam.
+
+"It's wonderful 'ow quiet she kept it," ses Peter.
+
+Old Sam stared at 'em agin, and then he asked 'em to speak in plain
+English wot they'd got to say, and not to go taking away the character of
+a woman wot wasn't there to speak up for herself.
+
+"It's nothing agin 'er character," ses Ginger.  "It's a credit to her,
+looked at properly," ses Peter Russet.
+
+"And Sam'll 'ave the pleasure of bringing of 'em up," ses Ginger.
+
+"Bringing of 'em up?" ses Sam, in a trembling voice and turning pale;
+"bringing who up?"
+
+"Why, 'er children," ses Ginger.  "Didn't she tell you?  She's got nine
+of 'em."
+
+Sam pretended not to believe 'em at fust, and said they was jealous; but
+next day he crept down to the greengrocer's shop in the same street,
+where Ginger had 'appened to buy some oranges one day, and found that it
+was only too true.  Nine children, the eldest of 'em only fifteen, was
+staying with diff'rent relations owing to scarlet-fever next door.
+
+Old Sam crept back 'ome like a man in a dream, with a bag of oranges he
+didn't want, and, arter making a present of the engagement-ring to
+Ginger--if 'e could get it--he took the fust train to Tilbury and signed
+on for a v'y'ge to China.

corpus/csb_macondo_v1.txt

@@ -0,0 +1,1308 @@
+US CHEMICAL SAFETY AND HAZARD INVESTIGATION BOARD 
+ 
+INVESTIGATION REPORT 
+VOLUME 1 
+EXPLOSION AND FIRE AT THE MACONDO WELL 
+(11 Fatalities, 17 Injured, and Serious Environmental Damage) 
+ 
+DEEPWATER HORIZON RIG 
+MISSISSIPPI CANYON BLOCK #252, GULF OF MEXICO 
+APRIL 20, 2010 
+KEY ISSUES IN VOLUME 1 
+• 
+MACONDO INCIDENT BACKGROUND AND GENERAL DESCRIPTION 
+• 
+DEEPWATER DRILLING AND TEMPORARY ABANDONMENT OF THE MACONDO WELL 
+ 
+REPORT NO. 2010-10-I-OS 
+ 
+6/5/2014 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+ 
+[This page left intentionally blank.] 
+ 
+2 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+Volume 1 
+Macondo-specific incident 
+events: Relevant background 
+on deepwater drilling and 
+temporary abandonment 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+3 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+ 
+[This page left intentionally blank.] 
+ 
+ 
+4 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+Contents 
+VOLUME 1 .................................................................................................................................................. 3 
+ACRONYMS AND ABBREVIATIONS ..................................................................................................... 7 
+1.0 
+MACONDO BACKGROUND AND INCIDENT SUMMARY ..................................................... 8 
+1.1 
+Involved Parties ............................................................................................................................... 8 
+1.2 
+The US Offshore Regulator ........................................................................................................... 10 
+1.3 
+The Well, the Rig, and the Crew .................................................................................................... 12 
+1.3.1 
+The Deepwater Horizon Rig ............................................................................................. 14 
+1.3.2 
+The Crew........................................................................................................................... 14 
+1.4 
+Planning the Well ........................................................................................................................... 15 
+1.5 
+Incident Description ....................................................................................................................... 16 
+2.0 
+DEEPWATER DRILLING AND TEMPORARY ABANDONMENT OF THE MACONDO 
+WELL ............................................................................................................................................ 18 
+2.1 
+Controlling Pore Pressures with Drilling Fluids ............................................................................ 19 
+2.2 
+Controlling Pore Pressures with Casing and Cement .................................................................... 23 
+2.2.1 
+Cement Integrity Testing and Final Displacement ........................................................... 26 
+2.3 
+Controlling Pore Pressures with a Blowout Preventer ................................................................... 28 
+2.4 
+Consequences of Explosion and Fire ............................................................................................. 31 
+REFERENCES ........................................................................................................................................... 32 
+ 
+5 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+Figures and Tables 
+ 
+Figures 
+Figure 1-1. Relationship between key companies associated with the Deepwater Horizon accident. .......... 9 
+Figure 1-2. Location of the Macondo well. ................................................................................................ 12 
+Figure 1-3. Timeline from when BP acquired the Macondo well lease until the Deepwater Horizon took 
+over drilling the well. .............................................................................................................. 13 
+Figure 2-1. During drilling, mud travels down the drillpipe, through the drill bit, and then back up the 
+annulus (yellow), carrying crushed rock back to the rig. ........................................................ 20 
+Figure 2-2. A simplified drilling margin plot. The planned mud weight (red dashed line) is formulated to 
+remain less than the fracture gradient (green line) and greater than the pore pressure (black 
+line). New casing transitions (green diamonds) are installed when the fracture gradient is 
+approached............................................................................................................................... 22 
+Figure 2-3. Cementing casing in place involves filling the annulus with cement above any hydrocarbon 
+bearing zones if they are present as well as a small length (30ˈ-90ˈ) in the shoe track........... 24 
+Figure 2-4. The final Temporary Abandonment configuration intended to remove drilling mud down to 
+8,367 feet to install a cement plug in seawater. ....................................................................... 26 
+Figure 2-5. The Deepwater Horizon BOP .................................................................................................. 29 
+ 
+Tables 
+Table 1-1. Total number of employees and revenue as reported by companies associated with the 
+Deepwater Horizon ................................................................................................................... 10 
+Table 1-2. Personnel On Board on April 20 by Company [NEED UPDATED TABLE] .......................... 14 
+Table 1-3. Well Control Personnel On Board the Rig on April 20, 2010 ................................................... 15 
+ 
+ 
+ 
+ 
+ 
+6 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+Acronyms and Abbreviations 
+APD 
+ 
+Application for Permit to Drill 
+BOEM 
+ 
+Bureau of Ocean Energy Management (United States) 
+BOEMRE 
+Bureau of Ocean Energy Management, Regulation, and Enforcement (United 
+States); the US offshore safety regulator between June 18 and October 1, 2011a 
+BOP 
+ 
+Blowout Preventer 
+BSEE 
+ 
+Bureau of Safety and Environmental Enforcement (United States); US offshore 
+safety regulator since October 1, 2011b 
+CSB 
+ 
+United States Chemical Safety & Hazard Investigation Board 
+DWH 
+ 
+Deepwater Horizon 
+EDS 
+ 
+Emergency Disconnect System 
+IADC 
+ 
+International Association of Drill Contractors 
+MMS 
+ 
+Minerals Management Service (United States); US offshore safety regulator at 
+the time of the Macondo accident until June 18, 2011c 
+MODU 
+ 
+Mobile Offshore Drilling Unit 
+OCS 
+ 
+Outer Continental Shelf 
+ONRR 
+ 
+Office of Natural Resources Revenue (United States) 
+ppg 
+ 
+pounds per gallon 
+SEMS 
+ 
+Safety and Environmental Management System 
+UK 
+ 
+ 
+United Kingdom 
+ 
+ 
+a Department of Interior, Order No. 3302, Change of the Name of the Minerals Management Service to the Bureau 
+of Ocean Energy Management, Regulation, and Enforcement (June 18. 2011), 
+http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=security/getfile&PageID=35872. Accessed 
+February 19, 2014. 
+b The Reorganization of the Former MMS, http://www.bsee.gov/About-BSEE/BSEE-
+History/Reorganization/Reorganization/..Accessed February 19, 2014. 
+c Department of Interior, Order No. 3302, Change of the Name of the Minerals Management Service to the Bureau 
+of Ocean Energy Management, Regulation, and Enforcement (June 18, 2011), 
+http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=security/getfile&PageID=35872. Accessed February 
+19, 2014. 
+7 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+1.0 Macondo Background and Incident Summary 
+At the time of the accident, the Deepwater Horizon (DWH) crew had finished drilling and was 
+completing temporary abandonment of the well so that a production facility could return later to extract 
+oil and gas from the well. 
+The Macondo well was exploratory in nature, meaning 
+significant uncertainty remained about the geology, the 
+petroleum resources, and the formation characteristics that 
+make the well easy or difficult to drill. Managing such 
+uncertainties ultimately determines a company’s success. 
+On the day of the April 20 tragedy, no effective safeguards 
+were in place to eliminate or minimize the consequences of 
+a process safety incident.a The safeguards (or barriers) 
+intended to prevent such a disaster were not properly 
+constructed, tested, or maintained, or they had been 
+removed. The management systems intended to ensure the 
+required functionality, availability, and reliability of these 
+safety critical barriers were inadequate. Ultimately, the 
+barriers meant to prevent, mitigate, or control a blowout 
+failed on the day of the accident. 
+1.1 
+Involved Parties 
+BP Exploration & Production Inc. (BP)b was and is the main 
+lease holder/operator of the block of landc that includes the 
+Macondo well site.d BP identifies itself as the largest 
+leaseholder in US Gulf of Mexico deepwater, owning more 
+than 650 different blocks of land in water depths of 1,200 feet or greater.1 
+Offshore lease holder/operators such as BP largely conduct deepwater well drilling and completion 
+activities through a number of contractors. Effective selection, oversight, and coordination among the 
+operator and various contractors are vital to safe offshore exploration. To drill the well at Macondo, BP 
+a A process safety incident is the unexpected releases of toxic, reactive, or flammable liquids and gases in processes 
+involving highly hazardous chemicals—Process Safety Management, OSHA 3132, 2000 (reprinted). 
+b BP p.l.c. is the parent company of many BP group companies, including BP Exploration & Production Inc. 
+(BPXP). When referring to “BP,” BPXP is intended unless otherwise stated. 
+c The Outer Continental Shelf has been divided into geographical areas referred to as blocks for identification 
+purposes on maps and in databases, http://www.data.bsee.gov/homepg/pubinfo/freeasci/leasing/leaselistdfn.asp. 
+dAs of February 23, 2010, U.S. Department of Interior documents indicate Anadarko E&P Company LP (22.5%), 
+Anadarko Petroleum Corporation (2.5%), MOEX Offshore 2007 LLC (10%), and BP Exploration & Production 
+Inc. (65%), shared leasing title interests, but as of December 5, 2011, BP retained 100%, 
+http://www.data.bsee.gov/PI/PDFImages/ACTIVE-LEASE/130/133905.pdf. Retrieved November 12, 2013. 
+Chapter 1.0 Overview 
+This chapter provides general 
+background as an introduction to the 
+CSB’s investigation of Macondo. It is 
+not meant to be all-encompassing. 
+Additional relevant information 
+including key findings appears in 
+subsequent volumes. 
+This chapter summarizes information 
+on the companies and entities 
+involved in the drilling and temporary 
+abandonment of the Macondo well, 
+the well itself, the Deepwater Horizon 
+rig, and the drilling crew aboard the 
+rig on the day of the incident. It 
+concludes with an incident 
+description summary that identifies 
+the failures in the hours leading up to 
+the explosions and fires aboard the 
+DWH. 
+8 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+contracted Transocean, the drilling contractor, and other well service providers, including Halliburton and 
+Sperry-Sun Drilling Services, a subsidiary of Halliburton (Figure 1-1). 
+As of November 2013, Transocean operated a worldwide fleet comprising 80 different drilling rigs.2 In 
+the US Gulf of Mexico, the fleet included 13 ultra-deepwater drilling rigs, which have the same water 
+depth capability as the Deepwater Horizon’s, 7,500 feet and greater. Transocean has stated that BP was 
+one of its most significant customers in 2012, accounting for approximately 11 percent of operating 
+revenues.3 
+As indicated in Figure 1-1, Cameron was not directly contracted to BP, but the original contract between 
+Transocean and BP specified the configuration of the blowout preventer and made specific references to 
+“Cameron or equivalent” components throughout the contract.4 Cameron provided updated parts, testing, 
+technical assistance, and repair services for the Deepwater Horizon BOP throughout its service period.a 
+ 
+ 
+Figure 1-1. Relationship between key companies associated with the Deepwater Horizon accident. 
+Transocean owned and operated both the Marianas and the DWH drilling rigs that were used at Macondo. 
+It also employed most of the onboard crew of both rigs. As the contracted driller, Transocean was in 
+charge of furnishing and maintaining materials, supplies, equipment, and services required for the drilling 
+and completion activities that occurred at Macondo.5 These services included maintaining well control 
+equipment, which the contract between BP and Transocean stipulated would be done according to good 
+oilfield practices and by “all reasonable means to prevent fire and blowouts.”6 BP retained control of how 
+various aspects of the drilling program would progress by specifying the completion activities (Section 
+1.5), the mud program (Section 2.1), and the casing program (Section 2.2).7 
+Halliburton Energy Services (Halliburton) and its subsidiary Sperry-Sun Drilling Services provided 
+cementing and well monitoring services to BP during drilling, completion, and temporary abandonment 
+activities at Macondo.8 
+BP, its contractors, and the BOP manufacturer operate worldwide and earn between $8 and $375 billion 
+dollars annually (Table 1-1). 
+a Cameron provided the CSB with numerous engineering report sheets, signed factory acceptance tests, repair sales 
+orders, and purchase orders. 
+9 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+Table 1-1. Total number of employees and revenue as reported by companies associated with the 
+Deepwater Horizon9 
+ 
+1.2 
+The US Offshore Regulator 
+At the time of the Macondo incident, Minerals Management Service (MMS), a division within the 
+Department of the Interior, was the primary offshore regulator responsible for overseeing offshore energy 
+operations to ensure compliance with relevant laws and regulations, predominantly the Outer Continental 
+Shelf Lands Act and 30 CFR Part 250.a MMS managed the nation’s natural gas, oil, and other mineral 
+resources on the Outer Continental Shelf (OCS). Its jurisdiction incorporated developing and 
+implementing plans for leasing conventional and renewable energy resources, safety and environmental 
+protection in all offshore energy activities, and revenue management. MMS minerals revenue amounted 
+to approximately $13 billion annually, approximately 95% of the total revenue collected by the 
+Department of the Interior.b,10 
+On May 19, 2010, four weeks following the Deepwater Horizon incident, then-Secretary of the Interior 
+Ken Salazar signed a Secretarial Order to separate and reassign the responsibilities of the Minerals 
+Management Service 11 into three independent entities: 
+a In addition to the Department of the Interior, several other federal agencies regulate safety and environmental 
+activities on the OCS. For instance, the US Coast Guard regulates marine safety, particularly the “safety of life 
+and property on Outer Continental Shelf (OCS) facilities, vessels, and other units engaged in OCS activities.” 33 
+C.F.R §140.1. The Environmental Protection Agency regulates air pollution from OCS sources (40 C.F.R. § 55.1) 
+and manages oil spill response in inland waters (40 C.F.R. Pt. 110 and 112). The Outer Continental Shelf Lands 
+Act grants the Occupational Safety and Health Administration the authority to enforce its regulations on the OCS. 
+However, if the working conditions are already regulated by another agency, the Department of the Interior and 
+the US Coast Guard, 4(b)(1) of the Occupational Safety and Health Act and 21(d) of OCSLA prevent OSHA from 
+duplicating their efforts. 
+b The Department also manages other natural and cultural resources, including Bureau of Indian Affairs, Bureau of 
+Land Management, Bureau of Reclamation, National Park Service, Office of Surface Mining, Reclamation and 
+Enforcement, U.S. Fish and Wildlife Service, and U.S. Geological Survey, 
+http://interior.gov/whoweare/index.cfm. Retrieved October 28, 2013. 
+10 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+• 
+The Office of Natural Resources Revenue (ONRR), responsible for the royalty and revenue 
+management function, including the collection and distribution of revenue, auditing and 
+compliance, and asset management. On October 1, 2010, the office began its duties.12 
+• 
+The Bureau of Ocean Energy Management (BOEM), responsible for the sustainable 
+development of the Outer Continental Shelf’s conventional and renewable energy resources, 
+including resource evaluation, planning, and leasing-related activities. 
+• 
+The Bureau of Safety and Environmental Enforcement (BSEE), responsible for the 
+comprehensive oversight, safety, and environmental protection of all offshore energy 
+activities. 
+The changes could not immediately take effect, so in the interim Salazar renamed MMS to Bureau of 
+Ocean Energy Management, Regulation and Enforcement (BOEMRE), to identify the agency’s role more 
+accurately.13 On October 1, 2011, BOEMRE ceased to exist after transferring its remaining 
+responsibilities to BOEM and BSEE.14 
+In the aftermath of the incident, BOEMRE and then BSEE took significant proactive steps to promulgate 
+new safety regulations, including the Interim15,a and Final [Drilling] Rules,16,b the Safety and 
+Environmental Management Systems (SEMS) Rule [30 CFR Part 250 Subpart S],17 and subsequent 
+amendments (SEMS II).18 
+While these are the principal entities of the Macondo case, additional companies, government agencies, 
+and stakeholder organizations are associated with the incident aftermath and general offshore operations. 
+Background information on relevant entities appears throughout the CSB Macondo Investigation Report 
+volumes. 
+a Requirements included a one-time recertification of BOPs, ROV capabilities and testing, autoshear and deadman 
+on dynamically positioned rigs, stump test of autoshear and deadman, deadman initial seafloor test, 
+documentation of BOP inspections and maintenance according to API RP 53, and, if shear rams activated on pipe 
+during well control, retrival and inspection of the BOP. 
+b Requirements included third-party verification of subsea BOP “compatibility” and up-to-date engineering, subsea 
+secondary BOP intervention capability and testing, BOP drillpipe shearing capacity at the maximum anticipated 
+surface pressure (MASP), third-party verification of shear calculations, and a BOP surface test between each well. 
+11 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+1.3 
+The Well, the Rig, and the Crew 
+The Macondo well is in the Central Gulf of Mexico, in Mississippi Canyon Block #252, approximately 50 
+miles from Louisiana, the nearest shoreline (Figure 1-2). 
+ 
+ 
+Figure 1-2. Location of the Macondo well. 
+BP acquired the lease for the Macondo well in March 200819 and began drilling there in October 200920 
+after the offshore regulator approved BP’s exploration plan and issued BP a permit to drill.21 Two rigs, 
+first the Marianas and then the DWH, were used to drill the Macondo well (Figure 1-3). The Marianas 
+drilled the Macondo well from October 6 to October 29,22 but the Marianas had to be moved to a shipyard 
+for repairs after being significantly damaged by a hurricane;23 the Deepwater Horizon replaced it, arriving 
+on site with a crew on January 31, 2010,24 and began setup and testing. Drilling resumed in February.25 
+12 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+Figure 1-3. Timeline from when BP acquired the Macondo well lease until the Deepwater Horizon took 
+over drilling the well. 
+BP planned to drill two exploration wells—Macondo being the first—and follow with a production 
+facility if the oil and gas-bearing region revealed commercial potential.26 The plan was to drill beyond the 
+primary target of approximately 18,400 feet to a total depth 20,200 feet to also assess the sections below 
+the target.27 The water depth of the Gulf at the location was just short of 5,000 feet. 
+BP designed Macondo for use as a producing well if successful, but the well was, in fact, exploratory 
+because of the uncertainty about both the type and quantity of the oil and gas (hydrocarbons) present at 
+the site and the effort necessary to actually extract the oil and gas. If the well proved commercially viable, 
+data concerning the well’s geology and hydrocarbon properties would be collected and used to create a 
+production plan; alternatively, if the well was not viable, the data would be gathered to determine why the 
+commercial predictions failed.28 
+Ultimately, as BP hoped, the Macondo well was appropriate for conversion to a producing well. 
+13 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+1.3.1 
+The Deepwater Horizon Rig 
+The DWH was a mobile offshore drilling unit (MODU) measuring 396 by 256 feet29,a with housing 
+capacity for 146 people.30 The DWH was a dynamically positioned rig that used global satellite 
+technology and thrusters to maintain position over the well rather than cables and anchors to hold it in 
+place.31 By their very nature, offshore rigs like the Deepwater Horizon MODU face unique hazards 
+compared to their onshore counterparts. For example, on a rig a substantial number of workers occupy a 
+small living and working area, where escape and rescue from a catastrophic event, such as a hazardous 
+chemical release, fire, or explosion, are inherently more difficult due to the offshore location. 
+1.3.2 
+The Crew 
+At the time of the blowout, 126 people employed by 13 different companies were onboard the DWH 
+(Table 1-2). 
+ 
+Table 1-2. Personnel On Board on April 20 by Company32 
+ 
+Eighteen of these individuals are typically identified as the crew intimately involved in the drilling and 
+temporary abandonment activities or having direct oversight responsibilities for those activities. (Table 
+a For comparison purposes, the dimensions of a National Football League football field are 360 by 160 feet. 
+14 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+1-3 provides additional details relevant in subsequent volumes of the CSB Macondo Investigation 
+Report.) 
+ 
+Table 1-3. Well Control Personnel On Board the Rig on April 20, 201033 
+ 
+1.4 
+Planning the Well 
+The goal of drilling a deepwater well is to create a pathway between oil and gas reservoirs trapped 
+beneath the seafloor and the surface. a To reach the reservoirs, a hole (the wellbore) is drilled through 
+a The general references describing drilling used in this chapter include Van Dyke, K. Fundamentals of Petroleum, 
+4th ed. Austin: University of Texas, 1997; Offshore Well Construction, 1st ed. Austin: University of Texas, 2005; 
+and A Primer of Oilwell Drilling, 7th ed. Austin: University of Texas, 2008. Readers may also review the Chief 
+Counsel’s report by the National Commission, which offers more detail than this report, but still at an introductory 
+level. See the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Chief 
+Counsel’s Report: The Gulf Oil Disaster, 
+http://www.oilspillcommission.gov/sites/default/files/documents/C21462-408_CCR_for_web_0.pdf (February 
+14, 2011). Accessed August 14, 2013. 
+15 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+various layers (formations) of rocks and/or unconsolidated sediments such as sand, shale,a gravel or silt.b 
+The formations, such as the target reservoir, are porousc and permeable, and they contain water, oil, 
+and/or gas which are under pressure. An unplanned flow of these fluids into the wellbore is called a 
+“kick,” which, if not managed, can progress to a “blowout,” the uncontrolled release of oil and gas 
+(hydrocarbons) from the well. This is most dangerous for people and property when the hydrocarbons 
+release onto the drilling facility, where ignition sources are present. 
+Thus, the flammable and potential explosive nature of oil and gas contained in the reservoir(s) of a 
+potential well is one of the most significant major hazards that must be managed throughout the lifecycle 
+of a drilling and production operation, beginning with the planning stages of the well. Part of the planning 
+process is a well-specific hazard analysis of the operation to determine the appropriate safeguards for 
+mitigating the hazard and control of the risks. (Volume 2, Chapters 4 and 5, of the CSB Macondo Incident 
+Investigation Report addresses the hazard analysis issue further). 
+1.5 
+Incident Description 
+On April 20, 2010, the drilling activities were completed after several productive oil and gas zones had 
+been discovered at Macondo, and the crew was performing a series of steps to temporarily abandon the 
+well. Abandonment activities would essentially plug the well so that the rig could move on to a new 
+drilling site and a production installation could return to the Macondo site at a later date to extract the 
+hydrocarbons. 
+BP’s temporary abandonment pland called for removal of most of drilling fluid column in the well before 
+installation of a surface cement plug.e Earlier, a critical cement barrier intended to keep the hydrocarbons 
+below the seafloor had not been effectively installed at the bottom of the well, and the cement integrity 
+was not not conducted in a way that provided a clear “pass” or “fail” result to the workers. Both BP and 
+Transocean personnel on the DWH rig misinterpreted the test results concerning the cement integrity, 
+leading them to erroneously believe that the hydrocarbon bearing zone at the bottom of the well had been 
+sealed when in fact it was not. When the drilling fluid column was removed, pressure gradually reduced 
+above the hydrocarbon reservoir at the bottom of the well. Eventually, this action allowed hydrocarbons 
+to flow past the failed cement barrier and up toward the DWH. Meanwhile, because of a failure to 
+recognize the increase in fluids from the well, the crew continued to remove more of the drilling fluid 
+column, causing both the hydrocarbon influx rate into the well and movement of hydrocarbons toward the 
+rig to increase. The hydrocarbons continued to flow from the reservoir for almost an hour without human 
+intervention or the activation of automated controls. 
+a Shale is a common deepwater rock. 
+b Silt is loose sedimentary material of a size between sand and clay. 
+c Porous formations constitute rock or other material that contains small spaces or holes that can hold liquids. 
+d A well may be temporarily sealed with cement or mechanical plugs to allow removal of the blowout preventer and 
+departure of the drilling rig. 
+e Cement plugs are portions of cement put into a wellbore to seal it. “Surface” is typically used to refer to the most 
+shallow cement plug used in a well. 
+16 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+The force of the hydrocarbons accelerating up the mile-long drilling risera resulted in well fluids gushing 
+onto the drilling rig floor—a blowout. At this point, the crew took action to activate the blowout preventer 
+(BOP). This safety critical element,b located at the sea floor, temporarily sealed the well but could not 
+stop the hydrocarbons that had already traveled above the BOP from releasing onto the rig. 
+Once oil and gas had risen above the BOP, the only action the crew could take was to divert it to a safer 
+location than onto the rig floor. However, the flow from the diverter had been preset to route well fluids 
+to the mud-gas separator rather than over the side of the Deepwater Horizon. The mud-gas separator was 
+rapidly overwhelmed, as it was not designed to safely handle a flow of the magnitude of the Macondo 
+blowout. As a result, drilling mud and hydrocarbons rained down onto the rig floor. The hydrocarbons 
+found an ignition source, and explosions and fire ensued. 
+As discussed in detail in Volume 2, both manual and automated emergency systems within the blowout 
+preventer were activated in an attempt to shear the drillpipe and seal the well. However, pressures in the 
+well had caused the drillpipe to buckle, which inhibited the BOP from sealing the well. 
+The explosion and fire resulted in 11 crew members suffering fatal injuries and 17 others being critically 
+injured.34 The Deepwater Horizon rig sank on April 22, 2010, about 36 hours after the initial explosions.35 
+Approximately 5 million barrels of oil spilled into the Gulf of Mexico.c 
+Ultimately, in the hours leading up to the incident, no effective barriers were in place to prevent or 
+mitigate a blowout. The physical barriers intended to prevent such a disaster were not properly designed 
+for the well conditions, constructed, tested, or maintained, or they had been removed. The management 
+systems intended to ensure the required functionality, availability, and reliability of these barriers were 
+inadequate. An examination of the treatment of safety critical equipment and tasks at Macondo, such as 
+the BOP and cement barrier testing, reveals opportunities for further improvements in effective barrier 
+safety management. Furthermore, a comparison of the US regulatory requirements for these safety critical 
+elements to other international offshore regimes illustrates gaps in the US model and offers support for 
+further post-Macondo changes to the US offshore safety regulations. 
+ 
+ 
+a A drilling riser is a large diameter pipe that connects a drilling rig to the BOP attached to the wellhead. 
+b As defined by the UK Health and Safety Executive, safety critical elements are controls (hardware, people 
+systems, or software) or tasks whose failure could cause or contribute to a major accident or which the purpose is 
+to prevent or limit the effects of a major accident; UK Offshore Installations (Safety Case) Regulations 2005, 2 
+Interpretation , http://www.legislation.gov.uk/uksi/2005/3117/pdfs/uksi_20053117_en.pdf. 
+c The total volume of oil spilled has yet to be determined by the U.S. District Court in the multidistrict litigation, but 
+estimates range from approximately 3.2 million to 5 million barrels. In Re: Oil Spill by the Oil Rig “Deepwater 
+Horizon” in the Gulf of Mexico, on April 20, 2010, U.S. Br. 1, January 27, 2014, ECF No. 12237; BP Br. 29, 
+January 24, 2014, ECF. No. 12227. 
+17 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+2.0 Deepwater Drilling and Temporary Abandonment of the 
+Macondo Wella 
+Drilling a well requires controlling the pressure exerted by 
+oil and gas trapped within the reservoirs that drillers are 
+trying to reach. The pressure, known as pore pressure or 
+formation pressure, is created in part by the weight of the 
+water and rock pushing down from above. 
+Pore pressure needs to be controlled throughout the subsea 
+drilling and well completion operations to minimize the 
+occurrence of well kicks—Macondo was a particularly 
+challenging well in this regard. Well control actions must be 
+initiated before a kick develops into an uncontrolled 
+hydrocarbon release into the environment—a blowout—
+because gas that travels up the riser and is released onto the 
+rig where ignition sources are present, is a serious threat to 
+people. 
+To control pore pressures and prevent kicks during drilling 
+and completion activities, drillers commonly use a variety of 
+physical barriers, including: 
+• 
+the weight of a column of fluid that fills the hole being drilled (wellbore) and the riser 
+• 
+steel casing and the cement used to secure it for protecting the sides of the wellbore and 
+preventing hydrocarbons from entering 
+• 
+cement placed at the bottom of a well to seal the hydrocarbon bearing zone 
+• 
+a “surface” cement plug—cement placed in a shallow location in the well close to the surface at 
+the seafloor—to seal the wellbore 
+• 
+drilling equipment known as a blowout preventer (BOP). 
+Each of these barriers is discussed briefly throughout this chapter, but the BOP receives additional in-
+depth discussion in Volume 2 of the CSB Macondo Investigation Report. An introductory discussion of 
+these barriers is necessary for a broader examination of the systemic, human, organizational, and 
+regulatory issues that contributed to the incident. This chapter provides a basic description of some 
+a This section focuses on deepwater drilling and temporary abandonment operations from a floating vessel, such as 
+the Deepwater Horizon rig. General references describing drilling include Van Dyke, K. Fundamentals of 
+Petroleum, 4th ed. Austin: University of Texas, 1997; Offshore Well Construction, 1st ed. Austin: University of 
+Texas, 2005; and A Primer of Oilwell Drilling, 7th ed. Austin: University of Texas, 2008. The Chief Counsel’s 
+report by the National Commission offers more detail than this report, but still at an introductory level. See the 
+National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling Chief Counsel’s Report: The 
+Gulf Oil Disaster, http://www.oilspillcommission.gov/sites/default/files/documents/C21462-
+408_CCR_for_web_0.pdf (February 14, 2011). Accessed August 14, 2013. 
+Chapter 2.0 Overview 
+This chapter focuses on the issue of 
+controlling formation pressures of the 
+well during the deepwater drilling 
+and temporary abandonment 
+operations at Macondo. Basic drilling 
+and completion activities are 
+described, integrated with facts 
+pertaining to the events of April 20, 
+2010. This information provides the 
+foundation for the CSB’s technical, 
+systemic, organizational, and 
+regulatory analyses in subsequent 
+report volumes. 
+18 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+underlying premises to offshore drilling and completion operations and the essential concepts that support 
+the CSB’s investigative analysis in subsequent volumes. 
+2.1 
+Controlling Pore Pressures with Drilling Fluids 
+The primary barrier used to control pore pressures while drilling is a column of fluid that fills the 
+wellbore and the riser. Various drilling fluids, such as water or water-based and oil-based drilling muds,a 
+are circulated down from the rig through the pipe used to drill the wellbore (drillpipe) and the drill bit 
+used to cut through the formations to create the wellbore. Afterwards, the same fluids carry the crushed 
+rock back around the drill bit up through the annular space between the drillpipe and wellbore (also called 
+the annulus) to the surface via the riser, a large diameter pipe that connects a drilling rig to the BOP 
+attached to the wellhead (Figure 2-1). The column of drilling fluid exerts hydrostatic pressure b on the 
+walls of the wellbore. When the hydrostatic pressure in the wellbore is greater than the pore pressure, the 
+well is said to be overbalanced. In this instance, the fluid column acts as a barrier by pushing back against 
+the pore pressure, thus keeping the hydrocarbons from entering into the wellbore. Keeping a well in this 
+overbalanced state is typically the primary means for controlling pore pressures and the basis of well 
+control. If for some reason the hydrostatic pressure drops below the pore pressure, the well becomes 
+underbalanced and a kick can occur. 
+Alternatively, if the pressure exerted by the drilling fluids is too high, it can exceed the “fracture 
+gradient,” or the pressure at which the walls of the exposed wellbore break down and drilling mud is lost 
+into the formation.c These “lost returns” or “lost circulation” events are costly due to expenses related to 
+the lost drilling mud, and they are also dangerous due to the resulting drop in the height of the drilling 
+fluid column, which may result in an underbalanced state if a sufficient volume of the fluid column is lost 
+to the formation and not replaced at the surface fast enough. This, too, can potentially result in a kick or, 
+even worse, a blowout.d 
+a Drilling muds are liquids and mixtures of liquids and solids circulated through the wellbore during drilling 
+operations. 
+b Hydrostatic pressure is exerted by liquid at a given point as a result of the weight of the column of fluid above it. 
+c The total pressure exerted by the drilling fluids will be a combination of the hydrostatic pressure and additional 
+pressure generated when the drilling fluids are circulated through the annulus. This can be expressed as 
+“equivalent circulating density” (ECD). 
+d Closing the BOP on a combined lost circulation event and well kick can lead to an underground blowout. In some 
+cases, an underground blowout can cause pressures to exceed either casing failure pressures or the burst pressure 
+of pressure relief valves known as rupture disks, which are designed to fail before the casing. (See Section 2.2 for 
+casing description). An underground blowout was a serious concern at Macondo because if the installed rupture 
+disks had burst due to the high blowout or kill pressures, a well flow up the annulus ultimately could have resulted 
+in a surface blowout. See National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, 
+Chief Counsel’s Report: The Gulf Oil Disaster, Chapter 4.2, 
+http://www.oilspillcommission.gov/sites/default/files/documents/C21462-408_CCR_for_web_0.pdf (February 
+14, 2011), Accessed August 14, 2013. 
+ 
+19 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+Figure 2-1. During drilling, mud travels down the drillpipe, through the drill bit, and then back up the 
+annulus (yellow), carrying crushed rock back to the rig. 
+20 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+Drilling fluid is formulated as a barrier to keep the pressure at the bottom of the well within the drilling 
+window or margin, which the International Association of Drill Contractors (IADC) defines as “the 
+difference between the maximum pore pressure and the minimum effective fracture pressure.”36 In its 
+well control manual in effect at the time of the Macondo incident, Transocean stated well planning is 
+highly influenced by the drilling margin, as it dictates how drilling is conducted to achieve an efficient 
+and safe operation.37 
+Applications to drill in the Gulf of Mexico must include the planned drilling margin,38 which is usually 
+submitted in graphic form. Figure 2-2 represents a simplified drilling margin plot and demonstrates that 
+the fracture gradient and the pore pressure typically increase as well depth increases, but not necessarily 
+uniformly or constant relative to one another. The planned drilling margin is given in terms of equivalent 
+mud density, reported in pounds per gallon (ppg), so that pressure can easily be related to the density of 
+the drilling mud column. Mud weight is formulated to remain within the drilling margin to keep well 
+fluids contained and to avoid fracturing the walls of the wellbore, risking a lost circulation event and 
+potentially a subsequent kick. Offshore US drilling regulations state: “[w]hile drilling, you must maintain 
+the safe drilling margin identified in the approved APD [Application for Permit to Drill]. When you 
+cannot maintain this safe margin, you must suspend drilling operations and remedy the situation.”39 The 
+regulations do not specify what the minimum drilling margin should be, but keeping the mud weight at 
+least 0.5 ppg under the fracture gradient is typically accepted practice.40 
+ 
+ 
+21 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+Figure 2-2. A simplified drilling margin plot. The planned mud weight (red dashed line) is formulated to 
+remain less than the fracture gradient (green line) and greater than the pore pressure (black line). New 
+casing transitions (green diamonds) are installed when the fracture gradient is approached. 
+22 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+2.2 
+Controlling Pore Pressures with Casing and Cement 
+To avoid exceeding the fracture gradient, the crew drills a well until the total pressure exerted by the 
+drilling fluids approaches the fracture gradient, at which point steel casing lines the wellbore to cover the 
+weaker formations.a Among other purposes,41 casing serves to strengthen the wellbore so that it does not 
+fracture or collapse during drilling. Casing is secured in a well by pumping cement into the annular space 
+between the casing and the formation, where it sets and hardens (Figure 2-3). The cement in the annulus 
+and at the bottom of the casing, referred to as the shoe track, should keep drilling fluids from flowing up 
+around the outside of the casing, thus protecting the wellbore, and it should prevent any hydrocarbons in 
+the surrounding formation from flowing into the well. Cement is a crucial physical barrier to secure the 
+integrity of the well, preventing ingress of hydrocarbons into the well and loss of well control. Yet, an 
+MMS study of offshore blowouts published in 2007 noted the most common contributing factor for 
+blowouts between 1992 and 2006 was cementing operations.42 Accordingly, cementing operations need to 
+be designed and managed in a manner that does not assume a successful cement job. 
+a “Casing” is a generic term for steel pipe. Formally, casing also refers to pipe if it extends up to the wellhead. A 
+section of pipe also can be hung from the bottom of a previous casing. In this case, it is called a “liner.” Liners can 
+hang from casing or from another liner. The intended effect on control of drilling margin is the same. 
+23 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+Figure 2-3. Cementing casing in place involves filling the annulus with cement above any hydrocarbon 
+bearing zones if they are present as well as a small length (30ˈ-90ˈ) in the shoe track. 
+After casing has been installed, heavier mud can then be introduced into the wellbore, and operations 
+continue by drilling past the cement at the bottom of casing. The steps observed in the red line of Figure 
+2-2 are points in the well where the intention is to install casing to protect the weaker formations higher 
+up in the well. Installing new casing can be exercised only a limited number of times because each new 
+installation has to fit down through the casings installed immediately before, so the new casing must be 
+smaller in diameter than the last. Few transitions can be made before the wellbore simply gets too narrow 
+for additional drilling. Current drilling mechanics and the size of well logging instrumentation limit the 
+minimum practical hole size to be a 6-inch diameter except in extraordinary circumstances.43 
+During the planning of the Macondo well, BP calculated how many times and at what depth to install a 
+casing or liner transitions.44 When drilling the Macondo well, the crew encountered differences in the 
+24 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+predicted geology, which resulted in shallower-than-anticipated transitions and ultimately a shallower-
+than-planned final depth. BP has acknowledged that the final section of the well was difficult to drill due 
+to a narrowing of the drilling margin as a result of an unusual reduction in the fracture gradient at the 
+bottom of the wellbore,45 but the already small diameter casing prohibited installation of additional casing 
+large enough to drill further. 
+Thus, drilling stopped on April 9, 2010, at 18,360 feet below sea level, short of the original well planned 
+depth of 19,650. Despite this change, the well had already encountered a good productive hydrocarbon 
+region for later production. Once the hydrocarbon zone was reached, BP decided to plug and abandon the 
+well for later hydrocarbon extraction. 
+The process of preparing the well so that the drilling rig can depart until another rig or production facility 
+returns is called temporary abandonment. For temporary abandonment to occur, the well needs to be 
+sealed; until it is, the hazards of a well kick and blowout are still very real. US regulations require cement 
+to be placed at the bottom of the well and the installation of a surface “retrievable or a permanent-type 
+bridge plug or a cement plug at least 100 feet long in the inner-most casing” with the top of the plug 
+required to be “no more than 1,000 feet below the mud line [sea floor]”46 unless the company seeks 
+approval for an alternative plan from the regulator.47 At Macondo, BP gained approval to set a surface 
+plug at approximately 3,000 feet below the seafloor. a,48 In its request, BP acknowledged this was a deep 
+surface plug and stated it planned to extend the surface plug length to 300 feet rather than the minimum 
+requirement of 100 feet “to compensate for the added setting depth.”49 In addition to choosing the deep 
+placement of the surface plug, BP also decided to set the surface plug in seawater rather than drilling 
+mud.b (Figure 2-4). 
+BP did not have a company standard for developing a temporary abandonment plan. For Macondo, BP 
+considered numerous temporary abandonment plan options in the week or so leading up to 
+implementation. These changes included the location of the surface plug, which ultimately affected the 
+negative pressure test conditions used to assess the bottom hole cement integrity (Section 2.3.1) and 
+displacement of the well.50 Many variations are possible for cement integrity testing, each with 
+advantages and disadvantages based on the particular circumstances of the well. (See Appendix 2-A, 
+Deepwater Horizon Blowout Preventer Failure Analysis, for details.) While the various temporary 
+a This depth was three times the regulatory maximum listed in MMS regulations (30 C.F.R. § 250.1721(d), 2010). 
+The Application for Permit to Modify cites concerns with a piece of equipment called a lockdown sleeve (LDS) 
+for the deviation. Post incident, BP stated in its investigation report that the depth of the surface cement plug was 
+governed by the procedure for installing the LDS. The crew would hang 3,000 feet of pipe in the well to generate 
+the 100,000 lbs. of weight necessary for installing the lockdown sleeve (BP, Deepwater Horizon Accident 
+Investigation Report, September 8, 2010, p. 72). The Chief Counsel’s Report generated by the National 
+Commission has challenged this assertion, stating other means were available to generate the necessary weight 
+that would not have allowed the surface cement plug to be set more shallow (National Commission on the BP 
+Deepwater Horizon Oil Spill and Offshore Drilling, Chief Counsel’s Report: The Gulf Oil Disaster, February 14, 
+2011, p. 141). 
+b See the panel discussion that BP, Transocean, and Halliburton participated in concerning setting cement plugs in 
+mud versus seawater, National Oil Spill Commission Meeting, November 8, 2010, pp. 209-216. 
+http://www.oilspillcommission.gov/sites/default/files/documents/Transcript-%20Meeting%205.pdf. Last accessed 
+July 25, 2013. 
+25 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+abandonment options BP explored improved the procedure, the CSB found no explicit risk assessment for 
+the final procedure used at Macondo. 
+ 
+Figure 2-4. The final Temporary Abandonment configuration intended to remove drilling mud down to 
+8,367 feet to install a cement plug in seawater. 
+2.2.1 
+Cement Integrity Testing and Final Displacement 
+US regulations require conducting a positive pressure test to verify that no leaks are in the well.a On the 
+day of the incident, the Deepwater Horizon drilling crew conducted a positive pressure test and 
+a During a positive pressure test, a well is pressured up and then held in this condition to see if the pressure is 
+maintained, indicating no leaks in the casing. If a decrease in pressure is observed, regulations require that either 
+the well be re-cemented, the casing repaired, or additional casing installed to ensure the well is sealed. 30 CFR 
+§250.423 (2010 and 2012). 
+26 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+determined the Macondo well passed the test.51 A major limitation of a positive pressure test is that it 
+does not check the cement sealing off the hydrocarbon bearing zones at the very bottom of the well for 
+inward leakage.a Even though regulations at the time of the incident did not require a negative pressure 
+test, BP’s final temporary abandonment plan also called for one.b 
+A negative pressure test can assess the integrity of the bottom-hole cement. It simulates an underbalanced 
+well by displacing some of the heavy drilling mud from the well and closing the BOP to isolate the 
+bottom of the well from the hydrostatic pressure exerted by fluids above the BOP. Various methods are 
+available to accomplish the test, and the specific procedure was left to those planning the process.c Yet, 
+neither BP nor Transocean management provided the Deepwater Horizon crew with a negative pressure 
+test procedure that included acceptance criteria to confirm test success or actions to take if any deviations 
+occurred during the test,d and the risks associated with conducting the negative pressure test were not 
+formally assessed. 
+To prepare for the negative pressure test at Macondo, a drillpipe was lowered to the depth identified for 
+the bottom of the cement plug (Figure 2-4). A viscous and dense water-based Loss Circulation Material 
+(LCM) followed by seawater was pumped down the drillpipe to displace the mud by pushing it above the 
+BOP toward the rig.e After stopping displacement and closing the BOP,f the crew observed the pressures 
+and/or flow from the well four times over three hours.g Each time, they observed unexpected results, so 
+a A positive pressure test ensures no outflow from the well into its surroundings. One way to conduct the test entails 
+closing the blind shear ram in the BOP (with no drillpipe present) and then pumping drilling mud down a pipe that 
+connects to the BOP below the closed ram to pressure up the well. Cement at the bottom of a well is usually 
+blocked from this pressure by a device known as a “wiper plug,” which is installed as part of the casing cement 
+job and which seals against outflow from the well. 
+b Regulations have changed post incident to require the negative pressure test, 30 CFR §250.423(c) (2012). 
+c Current regulations, 30 CFR §250.423(c), require the operator to submit a procedure and acceptance criteria for 
+approval. 
+d For example, instructions from the Ops Note included a single sentence, “With seawater in the kill close annular 
+and do a negative test ... 2350 psi differential,” Email communication, “Ops Note,” April 20, 2010, BP-HZN-
+BLY00071107, http://www.mdl2179trialdocs.com/releases/release201302281700004/Trocquet_David-
+Depo_Bundle.zip, Exhibit 1992. Accessed December 10, 2013. 
+e The Chief Counsel Report noted that BP chose to put the LCM into the well to avoid disposing the material as a 
+hazardous waste pursuant to the Resource Conservation and Recovery Act (National Commission on the BP 
+Deepwater Horizon Oil Spill and Offshore Drilling, Chief Counsel’s Report: The Gulf Oil Disaster, February 14, 
+2011, p. 151) . The LCM material had never been tested for this application, there was no operational reason to use 
+it, and the lost circulation material spacer was pumped into the well to avoid disposal of the material as a 
+hazardous waste pursuant to the Resource Conservation and Recovery Act. The viscous, gelling nature of the 
+LCM could have plugged a line the crew used to conduct the negative pressure test, greatly contributing to the 
+false positive interpretation of the test. See Appendix 2-A for more details. 
+f Most likely the lower annular preventer was closed. Witnesses at the hearings before the Deepwater Horizon Joint 
+Investigation Team gave contradictory recollections: May 27, 2010, p. 36; May 28, 2010, p. 120; August 25, 
+2010, p. 272. 
+g When displacement of the well was stopped to conduct the negative pressure test, as expected some trapped 
+pressure was in the drillpipe. The crew bled the pressure from the drillpipe, which should have resulted in a zero 
+pressure reading on the drillpipe. If the hydrocarbon bearing zone at the bottom of the well had been sealed, no 
+subsequent increase in pressure would have resulted. Pressure did increase and was bled two more times before 
+27 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+they made adjustments before deeming the well passed the final test. The crew’s actions suggest they did 
+not realize that the unexpected readings were indications of a failed negative pressure test and that 
+integrity of the cement had not been secured. (See Appendix 2-A for details.) 
+After the final negative pressure test was erroneously accepted as a “pass,” the Deepwater Horizon crew 
+continued the process of displacement, replacing the drilling mud in the wellbore and riser with seawater 
+in preparation to set the surface plug. Replacing dense drilling mud with seawater had the effect of 
+lowering the hydrostatic pressure on the bottom of the well. With the fluid column removed and no 
+surface plug yet set, the only means left for preventing the hydrocarbons from entering the riser and 
+eventually making their way up the well to the rig was detection of the kick by the crew and manual 
+activation of blowout prevention equipment to seal the well.a 
+2.3 
+Controlling Pore Pressures with a Blowout Preventer 
+If the drilling column fluid (mud weight) barrier and the cement barrier both fail, and the well is still open 
+(no plug installed), drilling crews depend on a blowout preventer (BOP) to control pore pressures. The 
+BOP has two primary roles during drilling and completion operations. First, it is a tool the drill crew 
+manually operates to control or regain control of the well during an initial kick by closing one or more 
+sealing elements. Second, it is an emergency response mitigation device with both manual and automatic 
+functions meant to shear drillpipe, seal the wellbore, and disconnect the rig from the well. A subsea BOP 
+(Figure 2-5) can be massive; the Deepwater Horizon BOP was nearly 57 feet tall and weighed 
+approximately 400 tons.52 The BOP is anchored to the top of the well casing at the seabedb and is 
+connected to a drilling rig by a riser. Drilling equipment, drillpipe, tubulars,c and other tools used in the 
+drilling process are lowered from the rig, through the riser, through the blowout preventer, and into the 
+well. 
+While subsea BOPs share general physical characteristics, the actual configuration, the control system, 
+and the performance requirements are specific to each BOP. The Deepwater Horizon’s BOP was built by 
+Cameron and had been used on the DWH since the rig began its service in 2001.53 
+The BOP components vary in their capabilities. Some seal the well around drillpipe, some seal open holes 
+(when no drillpipe is present), and others shear the drillpipe and seal the well. The arrangement of these 
+components within a BOP is based on the characteristics of the offshore operation and the anticipated 
+the crew used a lack of flow from the well as an indicator of a passed test despite a pressure increase that was 
+detected in the well. 
+a Technically, mechanical float valves also are located at the bottom of the well installed as part of the production 
+casing. These valves (also called check valves) allow cement used to install casing to flow one way out the bottom 
+of the casing, but not back up into the casing once cement pumping stops. BSEE does not consider float valves by 
+themselves a mechanical barrier, but they can and often do hold pressure. Float valves cannot be tested 
+independently. Thus, they cannot be considered a reliable device, but they have to fail for the well to flow. 
+b The National Commission generated a series of animations to depict not only BOP equipment placement and 
+activation but also helpful drilling practices. See links to animations at http://www.oilspillcommission.gov/chief-
+counsels-report. Last accessed July 30, 2013. 
+c As defined by Schlumberger Oil Field Glossary (http://www.glossary.oilfield.slb.com/search.cfm), a tubular is “A 
+generic term pertaining to any type of oilfield pipe, such as drillpipe, drill collars, pup joints, casing, production 
+tubing and pipeline.” 
+28 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+complexities. These components are identified in Figure 2-5, and the specific details of these components 
+on the Deepwater Horizon BOP are discussed in more detail in Volume 2. 
+ 
+Figure 2-5. The Deepwater Horizon BOP 
+ 
+29 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+When drilling mud and hydrocarbons began pouring out of the well and onto the Deepwater Horizon, the 
+drilling crew activated a component called an annular preventer, which should have sealed the space 
+around the drillpipe and prevented further hydrocarbons from rising above the BOP.a However, well data 
+indicate that this component failed to seal the well.b Not only did the riser fluids—the hydrocarbons, 
+drilling mud and seawater—that already passed above the BOP continue to travel up the riser and release 
+onto the rig floor, but the riser was also being replenished by the flow of even more hydrocarbons through 
+the leaking component. 
+Immediately after activating this component, the rig crew also closed the diverter at the top of the riser.54 
+When the diverter shut, flow up the riser exiting onto the rig floor was redirected to the diverter piping. 
+The two potential piping destinations were overboard into Gulf waters or to the Mud-Gas Separator 
+(MGS). On the day of the incident, the diverter was directed to the MGS. Moments after the diverter was 
+closed, the MGS was overwhelmed and hydrocarbons began blowing out of four different exit points onto 
+the rig. 
+Pressure datac indicate that the crew closed at least one additional sealing component of the BOP called a 
+pipe ram, which successfully shut in the well but caused the pressure in the drillpipe to build substantially 
+as evidenced by the surface drillpipe pressure building. (See Volume 2, Section 2.3 for details.) Riser 
+fluids above the BOP continued to unload onto the rig floor, but their replenishment temporarily ceased. 
+About two minutes later, the first explosions occurred on the rig and data transmission from the rig to 
+shore ceased. 
+In the minutes following the explosion, a crew member pressed the Emergency Disconnect System (EDS) 
+button on the bridge BOP remote control panel.55 This maneuver should have activated the BOP 
+components that would shear the drillpipe, seal the well, and disconnect the rig and riser from the BOP, 
+thus allowing the DWH to move away from the wellhead. However, there was no indication of EDS 
+actuation which was likely a result of the explosion damaging the rig-based BOP control systems and 
+power and communication lines between the rig and the BOP. 
+The explosion likely activated the AMF/deadman automatic emergency response system. This system 
+was meant to shear the drillpipe and seal the well, but as evident from the major oil spill that ensued, the 
+well remained unsealed. The likely activation of the AMF/deadman system and the failure of the BOP to 
+seal the well is discussed in detail in Volume 2 (Chapter 3) of the CSB Macondo Investigation Report. 
+a Witness statements said that the bridge remote control panel indicated that the lower annular was closed. Hearing 
+before the Deepwater Horizon Joint Investigation, May 28, 2010, p. 145. However, upon recovery, the lower 
+annular was found open [Bureau of Ocean Energy Management Regulation and Enforcement (BOEMRE), March 
+11, 2011. Forensic Examination of Deepwater Horizon Blowout Preventer, Report No. EP030842.] 
+http://www.uscg.mil/hq/cg5/cg545/dw/exhib/DNV%20Report%20EP030842%20for%20BOEMRE%20Volume%
+20I.pdf, p. 27. Accessed August 14, 2013. 
+b If the annular preventer had sealed, the drillpipe pressure at the surface would have rapidly increased to 5,000+ 
+psig (as when the upper pipe ram sealed at 9:47 p.m.). Rather, the drillpipe pressure fluctuated between 1,800 and 
+400 psig in this time period. 
+c See Appendix 2-A and the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, 
+Chief Counsel’s Report: The Gulf Oil Disaster, 
+http://www.oilspillcommission.gov/sites/default/files/documents/C21462-408_CCR_for_web_0.pdf (February 14, 
+2011). Accessed August 14, 2013, p.191. 
+30 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+2.4 
+Consequences of Explosion and Fire 
+Of the Deepwater Horizon crew, 11 suffered fatal injuries from the explosion and fire and 17 others were 
+critically injured.56 The Deepwater Horizon rig sank on April 22, 2010, about 36 hours after the initial 
+explosions.57 Approximately 5 million barrels of oil were spilled into the Gulf of Mexico.a 
+ 
+ 
+a The total volume of oil spilled has yet to be determined by the U.S. District Court in the multidistrict litigation, but 
+estimates range from approximately 5 million barrels to 3.2 million barrels. In Re: Oil Spill by the Oil Rig 
+“Deepwater Horizon” in the Gulf of Mexico, on April 20, 2010, U.S. Br. 1, Jan. 27, 2014, ECF No. 12237; BP Br. 
+29, Jan. 24, 2014, ECF. No. 12227. 
+31 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+References 
+ 
+1 BP, “Exploration and Production,” http://www.bp.com/en/global/corporate/about-bp/bp-worldwide/bp-in-
+america/our-us-operations/exploration-and-production.html. Retrieved November 12, 2013. 
+2 Transocean, http://www.deepwater.com/fw/main/Contract-Drilling-276.html. Retrieved November 12, 2013. 
+(Website link no longer active.) 
+3 Proxy Statement and 2012 Annual Report, Transocean, p. AR-9, http://phx.corporate-
+ir.net/External.File?item=UGFyZW50SUQ9MTc4NzQ5fENoaWxkSUQ9LTF8VHlwZT0z&t=1.Retrieved 
+November 1, 2013. 
+4 Transocean Drilling Contract for the Deepwater Horizon, 1998, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004271.pdf. Retrieved December 5, 
+2013. 
+5 Transocean Drilling Contract for the Deepwater Horizon, 1998, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004271.pdf. Retrieved December 5, 
+2013. 
+6 Transocean Drilling Contract for the Deepwater Horizon, 1998, BP-HZN-M8100021478, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004271.pdf. Retrieved December 5, 
+2013. 
+7 Transocean Drilling Contract for the Deepwater Horizon, 1998, BP-HZN-M8100021480, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004271.pdf. Retrieved December 5, 
+2013. 
+8 Contract for Gulf of Mexico Strategic Performances Unit Offshore Well Services between BP Exploration and 
+Production, Inc. and Halliburton Energy Services, Inc., BP-HZN-CSB00175428 - BP-HZN-CSB00175972. 
+9 BP Annual Report and Form 20-F 2012, p. 55. 
+http://www.bp.com/content/dam/bp/pdf/investors/BP_Annual_Report_and_Form_20F_2012.pdf. Retrieved 
+November 12, 2013; http://www.bp.com/en/global/corporate/about-bp/bp-worldwide/bp-in-america/our-us-
+operations/refining.html. Retrieved November 12, 2013; “BP at a Glance,” 
+http://www.bp.com/sectiongenericarticle.do?categoryId=3&contentId=2006926. Retrieved November 12, 2013; 
+Proxy Statement and 2012 Annual Report, Transocean, pp. AR-7 & AR-9, http://phx.corporate-
+ir.net/External.File?item=UGFyZW50SUQ9MTc4NzQ5fENoaWxkSUQ9LTF8VHlwZT0z&t=1. Retrieved 
+November 12, 2013; 2012 Annual Report, Halliburton, p. 38, http://phx.corporate-
+ir.net/External.File?item=UGFyZW50SUQ9MTc2OTU5fENoaWxkSUQ9LTF8VHlwZT0z&t=1, Retrieved 
+November 12, 2013; http://www.halliburton.com/en-US/about-us/history-of-halliburton-of-halliburton.page?node-
+id=hgeyxt5y; 2012 Annual Report, Cameron, pp 29, http://investors.c-a-
+m.com/file.php/88/2012+Annual+Report_1fc62ad8-a436-4016-bd33-82432de12d66.pdf. Retrieved November 12, 
+2013. 
+10 U.S. Department of Interior, “Salazar Divides MMS’s Three Conflicting Missions,” 
+http://www.doi.gov/news/pressreleases/Salazar-Divides-MMSs-Three-Conflicting-Missions.cfm. Retrieved 
+December 12, 2012. 
+11 The Secretary of the Interior, Order No. 3299, Establishment of the Bureau of Ocean Energy Management, the 
+Bureau of Safety and Environmental Enforcement, and the Office of Natural Resources Revenue, May 19, 2010, 
+http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=security/getfile&PageID=32475. Retrieved December 
+5, 2013. 
+12 Bureau of Safety and Environmental Engineering, “BSEE History,” http://www.bsee.gov/About-BSEE/BSEE-
+History/Reorganization/Reorganization.aspx. Retrieved December 12, 2012. 
+32 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+13 Secretary of the Interior, Order No. 3302, Change of the Name of the Minerals Management Service to the Bureau 
+of Ocean Energy Management, Regulation and Enforcement, June 18, 2010, 
+http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=security/getfile&PageID=32475. Retrieved December 
+5. 2013. 
+14 Bureau of Safety and Environmental Engineering, “BSEE History,” http://www.bsee.gov/About-BSEE/BSEE-
+History/index.aspx. Retrieved 12 December 2012. 
+15 Oil and Gas Sulphur Operations in the Outer Continental Shelf—Increased Safety Measures for Energy 
+Development on the Outer Continental Shelf; Final Rule, Docket ID BOEM–2010–0034, 75 Federal Register 198 
+(October 15, 2010), pp. 63,345-63,377. 
+16 Oil and Gas and Sulphur Operations in the Outer Continental Shelf—Increased Safety Measures for Energy 
+Development on the Outer Continental Shelf; Final Rule, Docket ID BOEM–2012–0002, 77 Federal Register 163 
+(August 22, 2012), pp. 50,856-50,901. 
+17 Final Rule, Oil and Gas and Sulphur Operations in the Outer Continental Shelf—Safety and Environmental 
+Management Systems, 75 Federal Register (October 15, 2010), p. 63,610. 
+18 Final Rule, Oil and Gas and Sulphur Operations in the Outer Continental Shelf—Revisions to Safety and 
+Environmental Management Systems, Docket ID: BSEE-2012-0011, 78 Federal Register 66 (April 5, 2013), pp. 
+20,423-20,443. 
+19 Minerals Management Service, High Bids Ranked by Bid Amount, Mar.19, 2008; (OCS Number G32306), 
+http://www.boem.gov/uploadedFiles/BOEM/Oil_and_Gas_Energy_Program/Leasing/Regional_Leasing/Gulf_of_M
+exico_Region/lsesale/206/rpt4_206.pdf. Lease ownership was shared with two other companies, Anadarko 
+Petroleum (25%) and MOEX Offshore (10%); Macondo Prospect Well Participation Agreement Deepwater Gulf of 
+Mexico (Exhibit 2852), http://www.mdl2179trialdocs.com/releases/release201302281700004/Strife_Stuart-
+Depo_Bundle.zip. 
+20 Application for Permit to Drill a New Well Approval, Lease G32306, Area/Block MC 252. Publically accessed at 
+http://www.mdl2179trialdocs.com/releases/release201302281700004/TREX-04021.pdf. 
+21 MMS Control Number N-09349 (BP-HZN-CSB00093568), April 6, 2009. 
+http://www.defenders.org/sites/default/files/publications/gulf_oil_disaster_complaint_exhibit_3_plan.pdf.; 
+Application for Permit to Drill a New Well Approval, Lease G32306, Area/Block MC 252. Publically accessed at 
+http://www.mdl2179trialdocs.com/releases/release201302281700004/TREX-04021.pdf. 
+22 Transocean, IADC Daily Drilling Report, Marianas, Report No.7 (October 6, 2009); Transocean, IADC Daily 
+Drilling Report, Marianas, Report No.30 (October 29, 2009). 
+23 Transocean, IADC Daily Drilling Report, Marianas, Report No.40 (November 8, 2009). BP-HZN-CSB00180108; 
+Transocean, IADC Daily Drilling Report, Signal Shipyard, Report No.1 (November 27, 2009). TRN-USCG_MMS-
+00011799 
+24 Transocean, IADC Daily Drilling Report, Deepwater Horizon, Report No. 1 (January 31, 2010). TRN-USCG 
+MMS-00011510- TRN-USCG MMS-00011513 
+25 Transocean, IADC Daily Drilling Report, Deepwater Horizon, Report No.12 (February 11, 2010). BP-HZN-
+CSB00055037- BP-HZN-CSB00055041 
+26 Initial Exploration Plan, Mississippi Canyon Block 252, OCS-G 32306 (Exhibit 6181). Publicly accessed at 
+http://www.mdl2179trialdocs.com/releases/release201302281700004/Tooms_Paul-Depo_Bundle.zip. 
+27 Application for Permit to Drill a New Well Approval, Lease G32306, Area/Block MC 252. Publicly accessed at 
+http://www.mdl2179trialdocs.com/releases/release201302281700004/TREX-04021.pdf , confirmed with CSB 
+interview. 
+28 Internal BP document, Gulf of Mexico SPU Well Planning Process Macondo, Wells Decision Support Package, 
+Stage Gate 1, 4/14/2009. (BP-HZN-CSB00182207) 
+33 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+29 Transocean Website, Fleet Specifications, Retrieved June 9, 2010. (Internet link no longer active.) 
+30 Deepwater Horizon Equipment List, April 27, 2009 (BP-HZN-CSB00020850). 
+31 Transocean Drilling Contract for the Deepwater Horizon, 1998. Publicly accessed at 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004271.pdf. Retrieved December 5, 
+2013. 
+32 Transocean Personnel-on-Board as of 20 Apr 2010 17:09:15 (TRN-USCG_MMS-00030435 – 00030441); 
+confirmed accurate with Weatherford September 1, 2010 response to the CSB interrogatory subpoena request for 
+information concerning personnel on board. 
+33 Transocean Personnel-on-Board as of 20 Apr 2010 17:09:15 (TRN-USCG_MMS-00030435 – 00030441); 
+[Persons on Board (POB); Well Control Handbook, Issue 3, rev.1, March 31, 2009 [TREX 1454]; Macondo Well 
+Incident – Transocean Investigation Report, Volume 1, p.17; Deepwater Horizon Operations Integrity Case, Section 
+2,Transocean Management System—HSE Management, Issue 1 (March 1, 2008) [TRN-MDL-02865361]; Contract 
+for Gulf of Mexico Strategic Performance Unit Offshore Well Services between BP Exploration and Production, 
+Inc., and Halliburton Energy Services, Inc., Section 3, Appendix 5, p.121 [BP-HZN-2179MDL00335470]. 
+34 BP plc (BP), Deepwater Horizon Accident Investigation Report, September 8, 2010, 
+http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cts=1331666404195&ved=0CCkQFjAA
+&url=http%3A%2F%2Fwww.bp.com%2Fliveassets%2Fbp_internet%2Fglobalbp%2Fglobalbp_uk_english%2Finci
+dent_response%2FSTAGING%2Flocal_assets%2Fdownloads_pdfs%2FDeepwater_Horizon_Accident_Investigatio
+n_Report.pdf&ei=x55fT7qYJunIsQKFqPSMCA&usg=AFQjCNE4cEa7fTYS0DYjDfGY60zekb6cqw. Accessed 
+March 12, 2012, and p. 9. Accessed August 14, 2013. 
+35 National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Chief Counsel’s Report: The 
+Gulf Oil Disaster, February 17, 2011, p. 18, 
+http://www.oilspillcommission.gov/sites/default/files/documents/C21462-408_CCR_for_web_0.pdf. Accessed 
+August 14, 2013. 
+36 IADC, http://www.iadclexicon.org/drilling-margin/. Accessed May 28, 2014. 
+ 
+37 Transocean, Well Control Handbook - Level: L1B, Issue #3, Revision #1 - HQS-OPS-HP-01, pp BP-HZN-
+2179MDL00330790. Publicly accessed at 
+http://www.mdl2179trialdocs.com/releases/release201303071500008/TREX-00596.pdf. 
+38 §250.414 (c) (2010 and 2012). 
+39 §250.427(b) (2010 and 2012). 
+40 Department of the Interior, Report Regarding the Causes of the April 20, 2010 Macondo Well Blowout, September 
+14, 2011, http://docs.lib.noaa.gov/noaa_documents/DWH_IR/reports/dwhfinal.pdf. Accessed December 9, 2013. 
+41 Offshore Well Construction, 1st ed. Austin: University of Texas, 2005: p. 3.1; R. Mitchell and S.Miska, 
+Fundamentals of Drilling Engineering, Society of Petroleum Engineers, 2011: p. 385. 
+42 D. Izon, E.P. Danenberger, and M. Mayes, “Absence of Fatalities in Blowouts Encouraging in MMS Study of 
+OCS Incidents, 1992 – 2006,” Drilling Contractor, July/August 2007, pp.84-90. 
+43 S. Christman, Email and telephone communications (2013). 
+44 BP p.l.c., Deepwater Horizon Accident Investigation Report, September 8, 2010, p. 16, 
+http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cts=1331666404195&ved=0CCkQFjAA
+&url=http%3A%2F%2Fwww.bp.com%2Fliveassets%2Fbp_internet%2Fglobalbp%2Fglobalbp_uk_english%2Finci
+dent_response%2FSTAGING%2Flocal_assets%2Fdownloads_pdfs%2FDeepwater_Horizon_Accident_Investigatio
+n_Report.pdf&ei=x55fT7qYJunIsQKFqPSMCA&usg=AFQjCNE4cEa7fTYS0DYjDfGY60zekb6cqw. Accessed 
+March 12, 2012. 
+34 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+45 BP p.l.c., Deepwater Horizon Accident Investigation Report, September 8, 2010, p. 33, 
+http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cts=1331666404195&ved=0CCkQFjAA
+&url=http%3A%2F%2Fwww.bp.com%2Fliveassets%2Fbp_internet%2Fglobalbp%2Fglobalbp_uk_english%2Finci
+dent_response%2FSTAGING%2Flocal_assets%2Fdownloads_pdfs%2FDeepwater_Horizon_Accident_Investigatio
+n_Report.pdf&ei=x55fT7qYJunIsQKFqPSMCA&usg=AFQjCNE4cEa7fTYS0DYjDfGY60zekb6cqw. Accessed 
+March 12, 2012. 
+46 30 C.F.R. § 250.1721(d) (2012). 
+47 30 C.F.R. § 250.1721(d) (2012). 
+48 Application for Permit to Modify, Lease G32306, Area/Block MC 252, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004032.pdf. Accessed August 8, 2010. 
+49 Application for Permit to Modify, Lease G32306, Area/Block MC 252, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004032.pdf. Accessed August 8, 2010. 
+50 Internal BP email, http://www.mdl2179trialdocs.com/releases/release201303141200012/TREX-00537.pdf. 
+Accessed August 8, 2010; Internal BP email, 
+http://www.mdl2179trialdocs.com/releases/release201303141200012/TREX-00097.pdf. Accessed August 8, 2010; 
+Application for Permit to Modify, Lease G32306, Area/Block MC 252, 
+http://www.mdl2179trialdocs.com/releases/release201305171200030/TREX-004032.pdf. Accessed August 8, 2010; 
+Macondo Drilling Production lnterval BP01 rev1, 
+http://www.mdl2179trialdocs.com/releases/release201303141200012/TREX-00836.pdf. Accessed August 8, 2010; 
+Macondo Drilling Production lnterval BP01 rev2, 
+http://www.mdl2179trialdocs.com/releases/release201303141200012/TREX-00545.pdf. Accessed August 8, 2010; 
+Transocean report, pp. 80-86, MC 252 #1 STOOBP01 - Macondo Prospect; 7" x 9-7/8" Interval; Version H.1, April 
+12; p. 10; BP-HZN-CSB00022750; Emails, February 28. Fowler to Stoltz, et. al., and replies; BP-HZN-
+BLY00062447; Email, April 14, 2:07 p.m.: Morel to Wilson and Sepulvado; BP-HZN-CSB00160178; MC 252 #1 
+STOOBP01 - Macondo Prospect; 7" x 9-7/8" Interval, Version H.2, April 15; p. 8; BP-HZN-C S B00027980; MMS 
+Form 124 APM; MC 252 #1; Temporary Abandonment Procedure _RevA.doc 4/16; BP-HZN-CSB00163048; 
+Email, April 18, 10:37 a.m.: Morel to Guide, and reply; BP-HZN-BLY00070087; Email Ops note, April 20, 10:43 
+a.m.: Morel to Vidrine, et. al.; BP-HZN-CSB00056581. 
+51 Transocean, IADC Daily Drilling Report, Deepwater Horizon, Report No.34, April 20, 2010, 10:30 am – 12:00 
+p.m. TRN-USCG_MMS-00011644 - TRN-USCG_MMS-00011648. 
+52 Bureau of Ocean Energy Management Regulation and Enforcement (BOEMRE), March 11, 2011. Forensic 
+Examination of Deepwater Horizon Blowout Preventer, Report No. EP030842, p. 15. 
+http://www.uscg.mil/hq/cg5/cg545/dw/exhib/DNV%20Report%20EP030842%20for%20BOEMRE%20Volume%2
+0I.pdf. Accessed March 12, 2012. 
+53 Transocean, Macondo Well Incident: Transocean Investigation Report Volume II, June 2011, 
+https://www.deepwater.com/_filelib/FileCabinet/pdfs/12_TRANSOCEAN_Vol_2.pdf, Appendix H. Accessed 
+December 9, 2013. 
+54 Hearing before the Deepwater Horizon Joint Investigation, May 29, 2010, p. 10. 
+(http://www.mdl2179trialdocs.com/releases/release201304110900026/TREX-37031.pdf, pp. BP-HZN-
+BLY00377488 – 489. Accessed August 9, 2013. The interview notes state “gas buster,” which is another name used 
+for the MGS. 
+55 Hearing before the Deepwater Horizon Joint Investigation, May 28, 2010, p. 145; Hearing before the Deepwater 
+Horizon Joint Investigation, May 27, 2010, pp. 11 and 190. 
+56 BP plc (BP), Deepwater Horizon accident investigation report, September 8, 2010, 
+http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cts=1331666404195&ved=0CCkQFjAA
+&url=http%3A%2F%2Fwww.bp.com%2Fliveassets%2Fbp_internet%2Fglobalbp%2Fglobalbp_uk_english%2Finci
+dent_response%2FSTAGING%2Flocal_assets%2Fdownloads_pdfs%2FDeepwater_Horizon_Accident_Investigatio
+35 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+n_Report.pdf&ei=x55fT7qYJunIsQKFqPSMCA&usg=AFQjCNE4cEa7fTYS0DYjDfGY60zekb6cqw. Accessed 
+March 12, 2012, and p. 9, accessed August 14, 2013. 
+57 National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Chief Counsel’s Report: The 
+Gulf Oil Disaster, February 17, 2011, p. 18, 
+http://www.oilspillcommission.gov/sites/default/files/documents/C21462-408_CCR_for_web_0.pdf. Accessed 
+August 14, 2013. 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+36 
+ 
+
+Macondo 
+Investigation Report Volume 1 
+June 5, 2014 
+ 
+ 
+ 
+37