Topic
Well Control
Control of formation fluids, kicks and blowouts during well operations.
Newest 100 Documents
All 150 in search- 202631 Mar
Notification, reporting and recording requirements for incidents
This guidance explains NOPSEMA notification, written reporting and record-keeping requirements for occupational safety, well-control and environmental incidents. It addresses reportability thresholds, safety-critical control impairment, harassment and bullying, monthly operational returns and environmental records. Illustrative examples distinguish performance-standard breaches from permitted exceptions when determining whether notification is required.
- 202631 Mar
Oil pollution risk management guidance note
Guidance for petroleum titleholders on evaluating oil pollution risks and preparing emergency response arrangements under environmental regulations. It addresses worst-case releases, oil fate and trajectory modelling, ALARP demonstrations, response resources and jurisdictional interfaces, alongside environmental monitoring, personnel competence, exercises and continuing assurance of response readiness.
- 202631 Mar
Source control planning and procedures information paper
This information paper sets out regulatory expectations for offshore loss-of-well-control preparedness across environment plans, well operations management plans and safety cases. It covers capping-stack selection and deployment, relief-well design and dynamic kill analysis, plume modelling, subsea dispersant supply, water-column monitoring, response-time modelling, coordinated operations and readiness exercises.
- 2026Feb
Well Workover
This regulatory inspection guide presents compliance questions for oil and gas well-workover operations. It covers prior approval, well-control fluid replenishment and measurement, crown-block safety checks, mud-pit level warnings, tubing and wellhead requirements, wireline leakage prevention, and pressure testing of newly installed lubricators against expected shut-in surface pressure.
- 2026Jan
D-PINCs (Operators Version - Jan 2026) — Drilling
A regulatory checklist for oil and gas drilling, linking numbered compliance questions to statutory authorities and enforcement actions. It addresses approvals, diverter configuration and testing, casing installation, cement placement, drilling-fluid management and monitoring. Further checks cover ventilation, gas detection, ignition prevention and retention of drilling and test records.
- 2026Jan
Well Operations
An inspection guide presenting compliance questions for well operations under Subpart G, with regulatory authorities and enforcement codes. It covers casing and liner integrity, surface and subsea blowout preventer configuration, pressure and function testing, maintenance and records, alongside specific requirements for coiled tubing and snubbing systems.
- 2025Dec
Office PINC List
An office compliance checklist pairs regulatory questions with cited authorities and enforcement codes. It covers operational approvals, structural records, financial security, well-control competence, spill preparedness, drilling and decommissioning. Further checks address pipeline maintenance and reporting, reservoir conservation, production measurement, and geological and geophysical permits and data submissions.
- 202326 Dec
Wendland 1H Well Fatal Explosion
CSB investigates a fatal blowout and fire during tubing-head replacement at a Texas oil and gas well. It analyses inadequate well-control planning, ineffective hydrostatic and valve barriers, and ignition-source management. Recommendations address workover methods for underpressured reservoirs, well-history review and gaps in industry guidance and federal regulation.
- 202214 Nov
MUX Cables and Hotline Hose Damage results in BOP Control Pods Losing Power and Communications
A subsea blowout preventer experienced partial communications loss while latched to a well. Excessive tension during harsh weather and extreme heave damaged the hotline hose and yellow and blue pod multiplexed communication cables. BOP control and operability remained available through the Acoustic Pod and subsea ROV panel.
- 20218 Mar
Inadequate Preparations in Advance of Inclement Weather Results in Excessive Rig Damage and Risk to Personnel
A drillship sustained substantial riser and related equipment damage during Hurricane Zeta after delayed evacuation and an emergency disconnect. No personnel casualties were reported. The alert recommends considering improvements to evacuation planning, well-securing procedures, shared emergency authority, weather communication, disconnect criteria and verification of equipment design limits.
- 202119 Jan
Well Control - Issue 6
An offshore well-control inspection guide using questions, model answers and success criteria to assess operational arrangements. It examines conventional, high-pressure high-temperature and managed pressure drilling, including BOP assurance, kick detection, hydraulic modelling, fingerprinting, pressure relief, contingency procedures and crew training. Inspection scoring supports subsequent regulatory intervention planning.
- 202119 Jan
Wells Personnel Competency Management System – Issue 6
An HSE inspection guide for assessing wells personnel competence management systems. It sets performance criteria and interview, record-sampling and scoring frameworks, covering individual and team assessment, contractor assurance, assessor training and external audit. Discussion includes non-technical skills, well-control drills and simulation-based training for challenging wells.
- 202029 Dec
Fixed well control equipment
NOPSEMA identifies gaps in thickness checking and tolerance verification for fixed mud gas separators, choke and kill pipework, and diverter pipework on mobile offshore drilling units. The alert discusses potential major accident consequences and recommends reviewing inspection and maintenance routines, with regular compliance audits.
- 2020
Fact Sheet BSEE BOEM Proposed Arctic Rule 2020
Fact sheet outlining proposed changes to Arctic exploratory drilling regulations, informed by research and Alaska Native consultations. It explains seasonal lease suspensions, mud and cuttings provisions, source-control equipment deployment, conditional capping-stack and relief-rig staging, subsea isolation alternatives, mudline cellars and removal of the Integrated Operation Plan requirement.
- 201912 Jun
Pryor Trust Fatal Gas Well Blowout and Fire
Investigation of an Oklahoma gas-well blowout and fire that killed five workers in the driller’s cabin. It examines underbalanced drilling, tripping methods, missed influx indications, disabled alarms, procedural and change-management deficiencies, blocked escape routes and unsuccessful blowout-preventer closure. Recommendations address drilling regulation, barrier assurance, alarm design and operating practices.
- 2019
Proposed Well Control Rule Revisions Fact Sheet
Technical fact sheet summarising BSEE’s final revisions to well-control regulations for offshore oil and gas operations. It explains changes to real-time monitoring, independent verification, accumulator requirements and alternating BOP testing schedules, alongside retained provisions for double shear rams, maintenance, ROV intervention and source control.
- 201814 May
Safety Alert 335 - Failure to Mitigate Known Hazards Leads to Kick
During well abandonment, trapped pressure beneath a bridge plug forced the plug and drill string 15 ft out of the hole, damaging rig equipment. The alert examines recognised hazards left without mitigation and recommends considering better hazard communication, actionable job safety analyses and methods for safely relieving pressure behind well barriers.
- 20173 Jul
Environmental Alert 001/2017
This alert examines capping-stack deployment where a 15,000 psi BOP contains a lower-stack annular preventer rated to 10,000 psi. For the described HPHT blowout configuration, it identifies the wellhead connector, after lower BOP removal, as the only attachment position tested to 15,000 psi, and requires consideration in oil-pollution emergency response strategies.
- 201625 Jul
Safety Alert 321 - Additional Catastrophic Incident Attributed to Ejection of Traveling Slips
BSEE reviews two well-abandonment incidents involving ejected travelling slips from hydraulic casing jacks. One caused crane-boom collapse; the other killed a supervisor and briefly left a well uncontrolled. Recommendations address reviewing slip-ejection hazards, considering alternatives to straight over-pull where pipe might part, and ensuring loads are free before crane lifting.
- 201628 Jun
Environmental Assessment
Final environmental assessment comparing regulatory alternatives for exploratory drilling in the Beaufort and Chukchi seas. It evaluates direct, indirect and cumulative effects of drilling-waste capture, well monitoring, source control, relief rigs and spill preparedness, balancing potential environmental benefits against additional operational disturbance and risks associated with more frequent BOP testing.
- 2016Jun
Regulatory Impact Analysis
Final regulatory impact analysis assesses Arctic offshore exploratory drilling requirements through a ten-year numbered scenario. It distinguishes baseline and incremental compliance costs, applies two discount rates, and evaluates potential avoided spill consequences. Substantive measures include source-control equipment, relief rigs, operational planning, testing, training and audits; benefit estimates retain substantial uncertainty.
- 2015Jul
2015-002 ST 220 Investigation of Loss of Well Control and Fire, Gulf of Mexico, July 23, 2013, South Timbalier Area Block 220, Well No. A-3 OCS-G 24980
BSEE investigates the South Timbalier A-3 blowout and subsequent fire during well completion on Hercules 265. It examines temperature-dependent brine density, seepage losses, kick recognition, shut-in procedures and unsuccessful BOP sealing. The report documents evacuation, depletion-relief drilling, regulatory findings and recommendations; the ignition source remains unknown.
- 20153 Mar
Environmental Alert 001/2015
An environmental alert describes damage to both multiplex BOP control lines on a MODU in the Canada–Newfoundland and Labrador Offshore Area after a securing saddle slipped approximately one metre. It highlights attachment robustness, installation procedures, management oversight, periodic inspection and readiness testing of acoustic, auto-mode and ROV back-up controls.
- 201510 Feb
Environmental Assessment
Draft environmental assessment comparing proposed Arctic exploratory drilling rules with alternatives, including no action. It examines pollution prevention, blowout-preventer testing, well monitoring, containment equipment and relief-rig availability in the Beaufort and Chukchi Seas. Analysis considers potential spill consequences, marine wildlife, subsistence practices and additional operational effects.
- 20145 Jun
Macondo Investigation Overview
Overview of the CSB investigation into the Macondo blowout during temporary well abandonment on Deepwater Horizon. It outlines the multi-volume report’s technical, organisational and regulatory scope, highlighting blowout preventer limitations, safety culture and international regulatory comparisons. It also describes evidence gathering, public hearings and obstacles to the investigation.
- 20145 Jun
Macondo Volume 1 Final Report
Volume 1 examines the Macondo blowout during temporary abandonment aboard Deepwater Horizon. It explains deepwater drilling, cement barriers, drilling-fluid pressure and positive and negative pressure tests. The report describes inadequate barrier assurance, separator overload and drillpipe buckling that inhibited BOP sealing, followed by explosions, fire and fatal injuries.
- 20145 Jun
Macondo Volume 2 Final Report
Volume 2 examines the Deepwater Horizon blowout preventer’s failure to seal the Macondo well, including off-centre drillpipe buckling, miswired solenoid valves and emergency-system assurance gaps. It uses forensic testing and modelling to assess barrier performance, comparing regulatory approaches and recommending lifecycle management and independent verification of safety-critical elements.
- 201421 May
Pressure Release After Ice Plug Removal Results in Injury
A snubbing operator removed ice from a production casing valve using a steel chisel after methanol proved unsuccessful. Although the valve was assumed closed, removal released high-pressure wellbore gas and fluid. The crew evacuated, retrieved the supervisor from the wellhead area and controlled the well by fully closing the valve.
- 201419 Jan
Safety Alert 306 - Trapped Pressure Beneath a Tubing Plug Blows Work String from Well
During offshore well recompletion, cutting tubing below a plug released trapped pressure and expelled 807 feet of work string. No injuries were reported. BSEE identified debris and sand obstructing plug flow and equalisation, and recommended pre-entry diagnostics, procedures addressing trapped pressure, and consideration of snubbing units where pressure remained uncertain.
- 20122 Jul
Safety Alert 302 - Pressure beneath a Surface Bridge Plug Blows Work String out of Well
During well abandonment, pressure beneath a surface bridge plug expelled 385 feet of work string and the bottom-hole assembly before the BOP sealed the well. Debris struck a diesel tank, releasing approximately five gallons into the Gulf. BSEE recommends reviewing re-entry procedures and accounting for pressure beneath plugs.
- 201217 Feb
Report - Montara investigation: Volume two
The second volume of an expert witness investigation examines nine issues surrounding the Montara hydrocarbon release. It assesses cement volumes, slurry properties, over-displacement, casing-shoe testing and corrosion-cap handling. Documentary analysis considers well suspension, barrier adequacy and programme changes, with proposed improvements to verification, contingency procedures and risk assessment.
- 201120 Sep
Failure of BOP Ram Yolk Results in a Natural Gas Release from BOP
A rigless snubbing operation experienced a natural gas release during ram-to-ram staging of production tubing. A broken stripping-ram yoke prevented adequate closing pressure and sealing. The operator closed the upper rams; damaged rams were subsequently removed for analysis. The BOP remained within its required certification period.
- 201114 Apr
Safety Alert 294 - Blowout Preventer Automatic Mode (Deadman) Activation
BOEMRE warns that a blowout preventer’s blind shear ram may reopen when power is restored following deadman activation. The alert recommends reviewing activation procedures and control logic, describes a possible blocking procedure, and explains requirements for seafloor testing and regulatory review during drilling permit approval.
- 200915 Dec
Safety Alert 284 - Diverter Flow Event
A semi-submersible completion operation experienced expanding formation gas in the riser and diverter discharge. The investigation established no specific cause, identifying possible packer communication, omitted reverse circulation and fluid-monitoring difficulties. Recommendations address brine pills, pressure monitoring, BOP sweeping, consideration of further circulation or bullheading, piping documentation and display scaling.
- 2009Sep
A guide to the well aspects of the Offshore Installations and Wells (Design and Construction etc) Regulations 1996. Guidance on Regulations
Explains the well provisions of DCR 1996, covering life-cycle integrity, subsurface assessment, material suitability, well-control equipment and examination schemes. It addresses operator responsibilities, reporting and competence, including suspension and abandonment, and clarifies interfaces with offshore safety cases and installation verification across offshore and land-based operations.
- 200925 Feb
Explosion/Flash Fire on Rig Floor Following Gas Release
An alert describes a well-control incident following drill-pipe logging and tripping. An influx was circulated using the Driller’s Method, but returns were lost. Repeated opening of the blowout preventer released mud and gas through the rig table. An explosive flash fire injured eight people, who were evacuated to hospital.
- 200812 Nov
Safety Alert 272 - Corroded Ring Gasket Causes Loss of Well Control
An MMS alert describes natural gas escaping through a corroded ring gasket during well scale-removal work. An inoperable subsurface safety valve prevented containment, and the platform was evacuated without injury. Acid treatment possibly accelerated gasket failure. Recommendations address acid-operation policies, emergency plans and gasket history or condition.
- 2008Nov
2008-054 Investigation of Loss of Well Control, South Pelto Block 10, Well No. 10, OCS-G02925, 14 February 2008, Gulf of Mexico off the Louisiana Coast..
Investigates natural-gas release during wireline scale removal and acid treatment at South Pelto Well No. 10. The panel identified ring-gasket corrosion, likely acceleration by acid treatment and an inoperable subsurface safety valve prolonging the event. It examines wellhead testing, integrity inspections and platform evacuation, recommending reviews of acid-operation policies and emergency plans.
- 20088 Oct
Safety Alert 269 - Loss of Well Control from Sustained Casing Pressure
An offshore well leaked gas at the mud line after earlier casing-pressure observations went unreported through required channels. Diagnostics suggested tubing-to-casing communication, but the investigation could not establish definitively how or why failure occurred. The alert recommends reviewing casing-pressure policies and clarifying reporting expectations in writing.
- 2008Oct
2008-049 Investigation of Blowout Eugene Island, Block 28 Well No. 4, OCS-G 05479, December 03, 2007, Gulf of Mexico, Off the Louisiana Coast.
Investigation of a workover blowout at Eugene Island Block 28, offshore Louisiana. Production tubing parted during pulling, allowing well pressure to eject tubing before preventers contained the annulus. Metallurgical examination identified fatigue cracking and flow-cut wall thinning. The report reviews barrier tests, work procedures and subsequent snubbing operations to kill the well.
- 2008Oct
2008-053 Investigation of Blowout, Main Pass Block 91 Platform A, OCS-G14576, August 23, 2007, Gulf of Mexico, Off the Louisiana Coast.
Investigation of a gas blowout at Main Pass Block 91 Platform A, followed by platform subsidence. The report examines sustained casing pressure, poor cement quality, diagnostic testing and procedural communication failures. It describes unsuccessful kill attempts and relief-well abandonment, while leaving the precise casing-failure mechanism unresolved and recommending abandonment of remaining wells.
- 200730 Jul
Safety Alert 252 - Retrieving Storm Packers
A storm-packer retrieval released gas and workover fluid, dislodging rotary bushings, injuring one person and splashing two others. An undetected gas bubble was identified, but its exact cause remained undetermined. MMS recommends retrieval procedures, a safety valve, kill-weight fluid, annular-preventer closure and restricting rig-floor personnel.
- 200712 Jun
Safety Alert 250 - Plug and Abandonment Operations Lead to Fatality and Brief Loss of Well Control
An MMS alert describes a fatal rig-less well abandonment incident in which parted tubing propelled casing-jack slips into an operator representative, briefly compromising well control. Findings address excessive pull, inadequate safety factors, unsuitable equipment, training and supervision. Recommendations emphasise contractor oversight, pre-job coordination, site verification and activity logs.
- 20066 Jul
Safety Alert 241 - Shallow-Gas Blowout and Rig Evacuation
A shallow-gas blowout during drilling in the South Timbalier area prompted temporary evacuation of non-essential rig personnel. The alert recommends considering additions to pre-spud planning, including review of historical logs and geophysical data, pilot holes and reserve kill-weight mud. It also discusses casing placement, flow checks and monitoring drilling mud properties.
- 20052 Sep
Flash Fire at Degasser Line Flare Pit Injures Worker
A worker suffered serious second-degree burns to his hands and face while attempting to relight a pail at a degasser-line flare pit. After pumping stopped and the well was shut in, his cigarette lighter sparked a flash fire involving methane venting from the line.
- 200531 May
Safety Alert 231 - Human Engineering Factors Result in Increasing Number of Riser Disconnects
This alert reviews accidental and emergency riser disconnects in deepwater operations, highlighting human error, hydraulic connection mistakes and station-keeping failures. It recommends reviewing existing requirements for deliberate sequential disconnection, protected controls and documented subsea function testing. An accompanying table summarises eleven events involving drilling and production risers.
- 20051 May
Inadvertent Unlatching of Wellhead Connector
A semi-submersible inadvertently unlatched a subsea wellhead connector on a recently perforated well. Differential pressure separated the stack and broke the seal, allowing riser fluid levels to equalise with seawater pressure. Reduced hydrostatic pressure permitted crude oil influx; prompt relatching restored the seal and averted a catastrophic well-control and environmental situation.
- 200518 Feb
Safety Alert 18 - Well-Control Equipment Circumvention
An MMS alert describes loss of well control during workover/completion after completion-fluid pumping stopped and a tubing hanger lockdown pin was removed, bypassing blowout prevention. Seawater and hydrocarbons escaped. It distinguishes direct from possible contributing causes and recommends improved hanger-landing procedures, well-control training and job safety analyses.
- 200528 Jan
Safety Alert 226 - Pressure Rise to Surface after Cementing Leads to Burst Casing and Loss of Control
An offshore well lost control when worn surface casing burst following pressure migration from a previously pressure-charged shallow reservoir. Misleading hydraulic gauge readings concealed rising annulus pressure. The alert recommends examining logs and cementing coverage, checking rig alignment and casing-wear indicators, and routinely checking hydraulic gauges for full lines and leaks.
- 200429 Nov
Safety Alert 223 - Loss of Well Control
A workover involving nitrogen washing removed a sand bridge from a well shut in for approximately ten years. Gas escaped through a corroded wellhead injection port where a seal assembly was absent, causing a minor condensate spill. The alert recommends reviewing maintenance and improving written instructions and job safety analysis.
- 200424 Jun
Safety Alert 221 - Hanger Failure and Ejection Lead to Well Control Incident
During a workover, hanger hold-down pins sheared at 6,150 psi, ejecting the hanger and tubing. Investigation identified inadequate pin engagement caused by a design flaw. The alert identifies affected Cameron products, recommends multiple well barriers and advises operators to consider shear rams for wells presenting unusual control problems.
- 20049 Feb
Safety Alert 219 - Loss of Well Control While Drilling Surface Hole
A well drilled from a producing platform encountered anomalous permeable sands and severe lost circulation. During tripping for surface casing, the well began flowing, mostly water, and was diverted downwind. Flow ceased after eight hours. MMS recommends reviewing shallow hazards even at previously drilled platforms, including formation anomalies beyond shallow gas markers.
- 20037 Dec
Loss of Well Control Results in Rig Fire
A drilling crew paused for an MWD survey when rising pit level and background gas indicated a worsening situation. After two calls to the company representative, the driller attempted to close in the well. The well unloaded and exploded, burning one employee’s back and resulting in total loss of the rig.
- 20034 Dec
Safety Alert 217 - Loss of Control Associated with Setting Surface Casing
This alert reviews loss of well control associated with surface casing cementing in the Gulf of Mexico since 1995. It reiterates recommendations for contingency procedures, planning before holding pressure with a diverter, communication to rig personnel, rig-specific supervisory training and cementing practices that protect against subsequent annular flow.
- 20037 Nov
Diverter Equipment – High Potential Consequences
Following surface-casing cementing on a Gulf of Mexico jack-up MODU, the well was shut in with the diverter in test mode. Rising pressure led to gas leakage through flow-line seals. Personnel evacuated, but the control configuration prevented remote diversion. No injuries or environmental impacts were reported.
- 200322 Oct
Safety Alert 216 - Loss Of Well Control: Annular Flow After Cementing
An alert describes annular flow after surface casing cementing. Using the diverter in test mode to retain pressure led to leaking riser seals and disabled remote control, followed by evacuation. Recommendations address contingency planning, pressure monitoring and diversion, communication, rig-specific supervisory training and review of shallow casing cementing practices.
- 200311 Jun
Safety Alert 213 - Marine Riser Failure
A drillship conducting dual activity in approximately 6,000 feet of water suffered marine riser failure while pulling drillpipe. ROV examination identified separated riser sections and mud release of undetermined quantity. Well-control equipment operated as designed, with additional shear rams activated by ROV. The alert highlights well shut-in requirements pending investigation.
- 20037 Apr
Safety Alert 212 - Shallow Gas Blowout and Rig Evacuation
A shallow-gas influx during a short trip led to uncontrolled flow, fire and abandonment of a drilling rig and producing platform. The alert discusses suspected swabbing and possible premature diverter failure, recommending review of old logs and seismic data, warnings to drilling crews, improved diverter design and safer nearby storage.
- 20038 Jan
Safety Alert 210 - Blowout After Cementing Surface Casing
An alert describes gas flow after surface casing cementing, increasing annulus pressure and subsequent gas emergence from adjacent wells. The platform was safely evacuated. Investigators identified probable cement-density regression and/or channel formation associated with delayed pumping. MMS recommends prompt cement pumping after landing casing and circulating at least one casing volume.
- 200219 Dec
Safety Alert 208 - Loss of Well Control
An MMS alert describes a kick during gravel-pack wash-over and a release through a mud-pump pressure safety valve during bull-heading. Investigators identified possible shear-pin deformation following repeated near-set-pressure exposures. Recommendations address visual inspection after such exposures, maintenance to manufacturers’ recommendations and routing valve discharges to a safe location.
- 200231 Oct
Safety Alert 205 - Blowout Results in Fatality and Injuries
An MMS alert describes a drilling blowout in which two men suffered hot-mud burns and one was lost during evacuation, presumed dead. Findings include a frozen safety valve, removed drill-pipe float and absent shear rams. Recommendations address backup valves, actuation and pressure testing, and reviews of pre-spud meetings and night-time illumination.
- 200115 Nov
Safety Alert 199 - Blowout and Fire
An alert describes a shallow-gas blowout during slip-on wellhead welding, unsuccessful attempts to kill the well with increasingly dense fluids, evacuation and a subsequent fire of unknown origin. Investigation identified inadequate cement design and communication failures. Recommendations address gas migration prevention, contractor communication and use of well-log information.
- 200116 Oct
Man Downed by H2S Gas
A well-service rig worker was overcome by hydrogen sulphide during a pump-down stripping job. As the well came in, he attempted to fit a stabbing valve to stop the flow. Operations were immediately suspended, and the worker was taken to hospital.
- 20005 Jun
Failure of Annular BOP Element
This alert describes a newly installed element in an annular blowout preventer cracking and failing during testing after delivery to a rig. It highlights the preventer’s critical role in well control and the potentially extremely hazardous condition resulting from its failure.
- 20003 Apr
Safety Alert 187 - Coiled Tubing Incidents
Two Gulf of Mexico coiled-tubing operations suffered tubing separation after encountering unknown obstructions. Failed well-control interventions and absent back-pressure valves led to uncontrolled flow and platform evacuation. The alert recommends hazard analysis, force limits, backflow protection, supervision, communication, equipment-specific procedures, training and weekly well-control drills.
- 20003 Mar
Safety Alert 186 - Accidental Disconnect of Marine Drilling Risers
Two accidental marine riser disconnects involved selection of the wrong control button and installation of a disconnect-switch lock-out device. The latter incident lost riser hydrostatic pressure and surface BOP control. The alert recommends assessing changes and communicating current activities, and stresses reliable backup BOP actuation.
- 2000
Calendar Year 2000
This MMS report compiles incidents reported from Outer Continental Shelf operations during 2000, covering Gulf of Mexico and Pacific regions. Statistical comparisons accompany category-organised narratives of fires, injuries, well-control losses, collisions and pollution. Case findings examine lifting failures, hot work, equipment condition and work planning, while distinguishing events from incident categories.
- 1999
OCS Report 1999
Statistical compilation of 1999 Outer Continental Shelf incidents in the Gulf of Mexico and Pacific regions, using TIMS records. It compares operational trends and presents case accounts of blowouts, fires, injuries, crane failures, collisions and pollution, including equipment behaviour, investigation findings and emergency responses. Appendices provide historical comparisons.
- 19986 May
Drilling Breaks
A rig continued drilling after a drilling break, then suffered lightning damage to its pit-volume monitoring system and loss of one mud pump. A gas bubble entered the wellbore. Annular preventer damage and apparent upper-ram failure preceded successful closure of the lower rams and killing of the well.
- 19986 May
Lightning Protection
Lightning disabled a drilling rig’s electronic pit volume totaliser, knocked one mud pump offline and caused minor SCR damage. A kick followed several minutes later and was eventually controlled by the crew. The contractor subsequently evaluated grounding methods in the hope of preventing recurrence.
- 1998
OCS Report 1998
This report compiles 1998 Outer Continental Shelf oil and gas incidents by region and event type, combining case narratives with graphical analysis. Pacific and Gulf of Mexico data cover well-control events, fires, collisions, fatalities, injuries and pollution. Cases examine equipment failures, work procedures and response measures, retaining uncertainty in reported causes.
- 199727 Aug
Safety Alert 171 - List of Gulf of America OCS Region Safety Alert and Accident Investigation Reports Concerning Blowouts
This notice indexes earlier safety alerts and accident investigation reports about Gulf of Mexico Outer Continental Shelf blowouts. It encourages operators to use previous incidents when designing and planning work to prevent recurrence, and lists report identifiers, accident dates, areas and blocks, with information on obtaining reports.
- 1997
OCS Report 1997
Compiles 1997 Outer Continental Shelf incidents from Pacific and Gulf of Mexico records, combining performance analysis with case narratives covering fires, blowouts, injuries, collisions and pipeline releases. Examines crane failures and lifting accessories, records incident responses and testing, and includes a separate crane review and historical statistical charts.
- 199617 Jun
Safety Alert 167 - Retrieval of Back-Pressure Valve Results in Loss of Well Control
A workover incident involving back-pressure valve retrieval released wellbore pressure, expelled fluids and blew rotary bushing inserts onto the drill floor, resulting in one fatality and two injuries. Inspection identified debris in the relief groove and a freely moving poppet. Recommendations address killing the well, equipment functionality, insert retention and checking for trapped pressure.
- 1996
Calendar Year 1995-1996
Regional compilation of Outer Continental Shelf incidents reported for 1995–1996, combining case narratives with graphical summaries. It covers well-control events, collisions, explosions, fires, fatalities, injuries and pollution in the Gulf of Mexico and Pacific regions. Incident types within a single event are counted separately, and some investigations remained pending.
- 19953 Apr
Safety Alert 165 - Shallow Gas Flows While Cementing Surface Casing
This alert examines four shallow-gas incidents following surface-casing cementing, attributed to formation-fluid migration before cement developed compressive strength. It discusses diverter removal, annular flow and well-killing methods, and considers cement properties, location selection, back pressure and shut-in options. Laboratory testing is suggested as a better basis for determining cement waiting time.
- 1994
Calendar Year 1991-1994
Compilation of Outer Continental Shelf oil and gas accidents during 1991–1994, drawing on investigator reports held in the OPAC database. Narratives cover blowouts, fires, explosions, pipeline leaks, significant pollution, injuries and fatalities, including equipment failures and emergency responses. Some incidents appear in multiple categories.
- 1994
CY 1991-1994 Addendum
This addendum records a fatal workover incident at well B-2 in South Marsh Island. Retrieving a back-pressure valve released trapped pressure and expelled well fluids and objects, killing one worker and injuring two. It identifies probable gas migration beneath the valve and describes pipe rams shutting in the well.
- 198919 Jul
Safety Alert 157 - Wireline Accident Involving the Formation of an Ice Plug in the Lubricator
An ice plug immobilised wireline tools in a lubricator. Bleeding pressure above the plug created a differential that propelled the plug and tools upwards, rupturing the lubricator. A subsurface safety valve shut in the well. The alert suggests retaining test pressure before opening the crown valve and using glycol in test fluid.
- 198623 Jan
Safety Alert 144 - Uncontrolled Shallow Gas Flow
A shallow gas flow during surface-hole drilling escalated when a diverter line parted and damaged the rig air supply. Loss of air pressure reopened annular preventers and prevented pipe-ram operation. The alert describes subsequent well control and modifications to diverter-line geometry and accumulator regulators with manual overrides.
- 198522 Aug
Safety Alert 145 - Tubing String Equipment Failure During a Plug and Abandonment Operation
During plug and abandonment, a telescoping swivel sub parted and trapped pressure expelled approximately 500 feet of tubing. Mismatched component designs and buckled internal parts were identified. The well was controlled without injuries. Recommendations address worst-case tool testing and, whenever feasible, killing the well and bleeding trapped pressure before unseating the completion string.
- 198518 Jun
Safety Alert 140 - Uncontrolled Well Flow and Pollution During Workover Operations
During reperforating, leaking casing hanger anchor screws were removed without securing the well, leading to uncontrolled flow and approximately 50 barrels of pollution. The platform was evacuated. The alert reiterates requirements for qualified, certified repair personnel, separation from downhole operations and management approval of procedures for repairs to unsecured wells.
- 19846 Jul
Safety Alert 130 - Fire
A Gulf of Mexico shallow gas blowout was diverted through port and starboard lines. Generator exhaust sparks were observed while mud and gas flowed; a flash fire followed drainage of the closed port diverter line. Water extinguished the fire without damage, and an exhaust-mounted spray nozzle was installed to prevent recurrence.
- 19845 Jan
Safety Alert 123 - Shallow Gas Blowout
A shallow gas blowout occurred while drill pipe was being withdrawn from a platform well. The crew diverted the flow and evacuated across a bridge; the well ceased blowing after approximately 45 minutes. The operator recommends continuous drill-floor supervision, checks before withdrawal, slow pipe movement and frequent hole filling.
- 19833 Oct
Safety Alert 119 - Successful Diverter System Operation to Control Shallow Gas Flow
An alert describes successful diversion of shallow gas during a drilling trip on a platform development well. Gas flowed through vent lines for approximately ten minutes before the hole bridged. Personnel evacuated and power was shut down. The operator planned adjustments to mud weight, drilling parameters and pipe withdrawal practices.
- 198313 May
Safety Alert 111 - Blowout and Fire
A platform well blew out after a diverter valve failed to open, the separator line plugged with gumbo and parted, and the annular preventer failed. Personnel evacuated without injury. The alert recommends frequent diverter operation, protected controls, less restrictive diversion where plugging is likely, and planned drilling parameters in severe gumbo areas.
- 198324 Mar
Safety Alert 110 - Fire
During casing running, a welder cutting a thread protector ignited gas migrating from the bell nipple, injuring a crew member filling the hole with mud. The alert describes BOP closure and hose extinguishment, reinforces prohibition of hot work near open wells, and recommends combustible-gas checks.
- 198217 Dec
Safety Alert 108 - Explosion and Fire
Dry gas accumulated during kick circulation and exploded from an unknown ignition source, causing a platform fire. Generator shutdown left no firefighting water pressure; a vessel extinguished the remaining fire after abandonment. The alert recommends regulating choke flow, considering direct gas venting and compliant electrical installations in classified locations.
- 198128 Aug
Safety Alert 106 - Blowout
This alert describes a blowout during completion of a dual-zone gas well following a reduction in completion-fluid density. Four people sustained slight injuries during evacuation, and a later fire destroyed platform facilities. Suggested precautions address fluid-level monitoring, maintenance scheduling and consideration of a low-fluid-loss polymer pill.
- 198130 Jun
Safety Alert 103 - Blowout
A Gulf of Mexico drilling blowout flowed through the drill string rather than the annulus. An inadvertently open fill-up valve and inaccessible lower kelly cock feature in the account; gas ignited and one fatality followed evacuation. The alert recommends immediate valve closure after pressure checks and accessible kelly positioning where possible.
- 198130 Mar
Safety Alert 100 - Explosion, Fire
An offshore safety alert describes an explosion and fire during well killing before snubbing. Returns were routed through a choke manifold into an open mud tank; escaping gas exploded, damaging the platform and injuring four men. The operator planned gas separation, safe vent routing and ignition-source inspections.
- 197915 Nov
Safety Alert 89 - Blowout and Fire, 8 Fatalities
An offshore drilling blowout released gas through the mud system after drillpipe and standpipe valves could not be closed. Ignition killed eight men and destroyed the rig. The alert records prolonged well-control efforts and the operator’s planned expansion of pressure testing across mud-system equipment and piping.
- 19781 Dec
Safety Alert 81 - Blowout
A water injection well intersected a gas-lifted producing well during drilling, causing a blowout and platform evacuation. One roustabout sustained minor injuries, and the drilling rig suffered considerable damage. The alert describes directional surveys, interference plotting and monitoring drilling parameters to recognise and halt impending well interference.
- 19785 Sep
Safety Alert 73 - Gas Leak from Subsea BOP Stack While Circulating Out Kick
A semisubmersible rig was evacuated after gas escaped from its subsea BOP stack during kick circulation. A non-conforming ring gasket failed to seal, and escaping fluids damaged a hydraulic line, preventing BOP operation and riser release. The alert records the operator’s planned gasket quality controls and flange-standoff verification procedures.
- 197812 Jun
Safety Alert 70 - Blowout During Workover
A workover well apparently swabbed in while a perforation wash tool was being withdrawn. A safety valve failed to close; sand in its working parts could have contributed. The alert recommends mud monitoring during pipe tripping, reserving safety valves for well control and checking valve operation before withdrawal.
- 19776 Dec
Safety Alert 69 - Blowout, Platform Loss
An offshore development well suffered a gas blowout during attempts to kill a deep saltwater flow. Gas jetting formed a seabed crater, undermining the platform legs; personnel evacuated safely before it toppled. The alert reviews drilling warning signs and planned casing-integrity checks, cement evaluation, well-control training and reassessment following operational deviations.
- 197726 Sep
Safety Alert 66 - Blowouts from Surface Casing, Conductor Casing Annulus
This alert describes delayed shallow gas flows between conductor and surface casing after cementing, sometimes requiring abandonment or vessel relocation. It attributes the flows tentatively to reduced cement-column hydrostatic head and outlines logging, casing movement, slurry selection, returns monitoring and conditional retention of blowout-preventer capability.
- 19775 May
Safety Alert 64 - Uncontrolled Gas Flow
An offshore drilling alert describes uncontrolled well gas flow after a safety-valve grease fitting failed during well-killing operations. A combustible atmosphere prompted evacuation; the well bridged two days later without injuries, fire or pollution. The operator replaced valve grease fittings with solid plugs and pressure-tested the valves.
- 197623 Jun
Safety Alert 45 - Tubing Blows Out of Well, Men Injured
An offshore workover incident expelled 600 feet of tubing when it was disconnected, leaving five workers with minor injuries while fleeing or being struck by debris. The alert describes the tubing plug and closed subsurface safety valve arrangement, and the operator’s planned well killing and valve blocking measures to prevent trapped gas.
- 197621 Jun
Safety Alert 43 - Shallow Gas Blowout
An offshore drilling alert describes a shallow gas blowout after casing cementing and blowout preventer removal. The platform was abandoned and control restored sixteen days later without injury, fire or pollution. The operator suspected cement bridging and hydrostatic pressure loss, and adopted low-water-loss, quick-setting cement and casing reciprocation.