ultra positioned semi offshore oil drilling rig owned built south_korea rig commissioned later registered leased september september rig deepest oil history vertical depth measured depth block approximately miles southeast houston feet water april drilling prospect explosion rig caused killed crewmen ignited visible miles away resulting fire extinguished april sank leaving causing largest oil spill waters design fifth generation design model type positioned column stabilized semi mobile offshore drilling unit designed drill wells oil exploration production psi kpa outside diameter marine second semi rig constructed class predecessor positioned rig capable operating waters feet deep maximum drill depth approximately offshore capable drilling waters deeper class column stabilized drilling unit rig upgraded drill drill monitoring system technical personnel based houston texas received real time drilling data rig transmitted maintenance information advanced systems played key role rig operation pressure drill monitoring technology automated systems modelling systems cement modelling system april played crucial cement mix support decisions decisions focus investigations explosion rig month history construction ownership horizon built later south_korea construction started december keel laid march rig delivered february acquisition december rig registered switzerland subsidiary operated rig flag convenience rig leased year contract deployment gulf_of_mexico following construction lease renewed year years years covering contract worth million day bare rig crew gear support vessels estimated cost according sec transfer document falcon dated august rig specified official registration number number gross net transfer value million rig million covering replacement cost wreckage removal drilling operations horizon worked wells atlantis oil fields described times lucky celebrated rig described powerful world discovered oil oil field giant field field vertical depth measured depth water deepest oil world feet rig official drilling specification stated company fleet list february commenced drilling mississippi canyon block miles southeast coast louisiana water depth approximately feet prospect exploration rights acquired prospect jointly owned offshore working site april violent explosion occurred leading destruction rig resulting oil spill final stages completion time cement injected rig shortly role semi permanent production platform site followed return field work described concluded permission requested terminate operations site operational lifetime rig actively operation working life days remainder partly relates time spent sites regulation safety inspection renamed june regulatory body offshore oil drilling united_states_of_america according associated_press investigation certain safety documentation emergency procedure information including documentation exact incident later occurred absent exact number required monthly performed varied time carried required months omitted investigation notes partly expected circumstances weather movement inspection reports provided freedom information legislation taken hours lifetime rig received non compliance safety including pollution sixth citation related non grounded electrical equipment later withdrawn equipment determined regulations overall horizon safety record strong according drilling consultant reviewing information herald horizon industry model safety according investigation record according officials rig informal watch list problem explosion oil spill april final phases drilling erupted marine rig shooting air soon followed eruption combination drilling mud gas water gas component material quickly transitioned fully state ignited series explosions attempt activate failed final defense prevent oil spill device known blind shear ram activated failed plug time explosion crew board seven employees employees companies involved operation rig including workers presumed killed initial explosion rig evacuated injured workers medical facilities approximately hours sank april remains rig located resting approximately deep location quarter mile northwest resultant oil spill continued july closed cap relief wells permanently seal declared effectively dead september aftermath received early partial insurance settlement total loss million financial analysts noted insurance recovery likely value rig necessarily replacement value estimated million litigation ultimate roll damage scope final insurance recovery unknown june analysts reporting aftermath unprecedented scale complexity compared previous disasters took years resolve july analysis aftermath cited legal sources saying point scale litigation large novel situation likely complicated variety probable cases means hard aggregate called class actions way historical context faced like disaster litigation discussed terms year january agreed pay billion violations clean water act earlier agreed pay billion faced additional penalties range billion billion september agreed settle large percentage legal claims paying billion trust way installments years september district judge ruled guilty gross misconduct clean water act described actions reckless said actions blame spill issued statement strongly finding saying court decision appealed
Deepwater Horizon