- 10 workers onboard; no fatalities reported at this time
- Bankrupt operator: Shebah Exploration & Production Company Ltd
- Trinity Spirit FPSO moored in only 80′ of water
- 22,000 bopd maximum production
- 2 million bbls max. storage
- Aging vessel: built in 1976; last upgrade in 1997
Archive for the ‘well control incidents’ Category
FPSO fire offshore Nigeria
Posted in accidents, well control incidents, tagged FPSO fire, Nigeria, Shebah E&P on February 3, 2022| Leave a Comment »
Macondo: Still matters to be resolved
Posted in drilling, Gulf of Mexico, well control incidents, tagged blowout, bp, LSU, macondo, Mayank Tyagi, top kill on September 28, 2021| Leave a Comment »
While the official BOEMRE-USCG and National Commission/Chief Counsel investigation reports were quite good and there are countless court documents and ad hoc reviews of the blowout, some important Macondo issues have not been fully addressed. BOE will touch on these issues periodically starting with the decision to terminate the top kill operation on 5/28/2010.

The top kill operation (see diagram above) was intended to overcome and halt the flow of oil by pumping heavy mud into the well bore. The operation was not successful because the pumping rate and mud weight did not generate sufficient pressure. Per an excellent paper by Dr. Mayank Tyagi and colleagues at LSU (Analysis of Well Containment and Control Attempts in the Aftermath of the Deepwater Blowout in MC252):
It is very likely that if the top kill had been designed to deliver more than 109 bpm of 16.4 ppg drilling fluid below the BOP stack for a sustained period, the Macondo blowout could have been stopped between May 26-28, 2010. Given that the well was successfully shut-in with the capping stack in July, and that the subsequent bullhead (static) kill was successful, certainly a higher rate top kill would have been successful at that time.
The American Thinker, citing the New York Times, reports that Energy Secretary Chu stopped the top kill operation over the objections of some BP engineers. While it was reasonable to be concerned about possible casing leaks and the fracturing of subsurface formations, the subsequent (7/15/2010) closure of the capping stack demonstrated that the well had sufficient integrity to support the top kill operation. Questions regarding why a higher rate top kill effort was not attempted and how that decision was made are therefore important and merit discussion. Did the Macondo well flow unnecessarily into the Gulf for an additional 48 days (5/28-7/15)? Did the National Incident Command facilitate or delay source control?
Keep in mind that the NIC almost made a similar mistake in July. Even after the capping stack successfully shut-in the well on 7/15, Incident Commander Thad Allen (USCG) continued to call the closure of the capping stack a temporary test and threatened to require BP to resume flow from the well. Fortunately, informed input from experienced engineers prevailed. The well remained shut-in and the static well-kill operation was successful.
BOE is committed to recognizing safety leadership
Posted in accidents, Australia, offshore, Regulation, well control incidents, tagged BSEE, IOGP, NOPSEMA on August 2, 2021| Leave a Comment »
Continuous improvement has to be the primary objective of offshore safety leaders, and this independent blog is committed to recognizing initiatives that further reduce safety and environmental risks. Australia’s collaborative mental survey project is an interesting such initiative in its early stages. Two other important initiatives are noted below.
BSEE’s Dropped Object Risk-Based Inspection initiative: As has been the case for 50 years, most offshore fatalities and serious injuries are associated with falls or falling and moving objects/equipment. BSEE’s Dropped Objects initiative, as described in a presentation by Jason Mathews during a recent Center for Offshore Safety (COS) webinar is intended to draw further attention to and better manage these risks. In addition to BSEE’s focused inspections, the “Good Practices” being followed by some operators and contractors, as described on pages 40-50 of the presentation, are encouraging. These types of initiatives are necessary if we are to achieve the elusive “zero fatality” year on the US OCS.
IOGP process safety guidance, Report 456 v.2 : Contrary to some post-Macondo narratives, process safety and well control were always the primary focus of the US OCS regulatory program. In 1974, my boss Richard Krahl (known as “Mr. OCS” for his commitment to offshore safety) dropped a copy of the first edition of API RP 14C (Analysis, Design, Installation, and Testing of Safety Systems for Offshore Production Facilities) on my desk and told me it was an excellent document that I should read. RP 14 C and other process safety standards were incorporated into the USGS OCS Orders (regulations) in the 1970’s. For decades, the USGS and MMS were leaders in well control and production safety research and training. That said, better indicators and improved approaches to offshore facility process safety were needed, and the International Association of Oil and Gas Producers report has provided an excellent framework. Report 456 is comprehensive and technically sound, and provides excellent guidance and examples. Very well done!
Must read piece for those following the Macondo investigations
Posted in accidents, well control incidents, tagged accidents, blowouts, Deepwater Horizon, drilling, Gulf of Mexico, macondo, offshore drilling, safety, well control on August 4, 2011| 4 Comments »
- The well clearly had losses through the shoe during the initial displacement of the heavy spacer with seawater, immediately prior to the negative test.
- Allowing for, and accepting, losses of ~80 bbls during spacer displacement, explains ALL pressure and flow anomalies without the need to create or invoke undocumented and unsubstantiated valve closures or manipulations that contradict witness testimony of events. It also eliminates the need to adopt unrealistically-low pump efficiencies for the rig pumps, hypothetical washed-out tubing and ridiculously high viscosities for the drilling mud, in an effort to fit questionable computer models.
- Despite extensive examination by investigators and the publication of several reports, the fact that the well experienced losses, making it even more severely underbalanced than was planned, has been given little credence or has received little or no attention, despite several clear indications that this was the case. While this statement regarding losses may be self-evident, its significance on the outcome at Macondo merits closer examination since it explains many previous, apparently-contradictory aspects of the disaster.
- Under-displacement of heavyweight spacer, as a result of losses during displacement, caused U-tubing and partial evacuation of the kill line, the lower end of which was later refilled with heavyweight spacer, driven by pressure and flow from the formation. The vacuum, initially, and subsequent invasion of heavy fluid rendered the kill line useless for monitoring the well since the line was effectively blind to pressure changes in the well.
- While initial flow into the well was through the shoe, pressure above the casing hanger seal during the negative test was reduced to levels that could have allowed the casing to lift, compromising the seal and possibly also allowing flow from the external annulus.
- The well encountered further losses during the second displacement (to displace the riser), after completion of the negative test. These losses, which were perhaps as much as 200 bbls, effectively replaced heavy mud with sea water in the casing below the drill pipe. This further underbalanced the well to the point that it was being kept under control only by pumping friction pressure. As the pump rate was reduced prior to shut down for the sheen test, effectively reducing system backpressure, the now severely underbalanced well began to flow.
Rapid bacterial consumption of Gulf oil confirmed
Posted in accidents, well control incidents, tagged blowouts, Deepwater Horizon, Gulf of Mexico, macondo, oil spill, oil-eating bacteria, Woods Hole Oceanographic Institute on August 2, 2011| Leave a Comment »
Woods Hole Oceanographic Institute scientists have published important new findings on the rapid bacterial degradation of the Macondo spill.
They found that bacterial microbes inside the slick degraded the oil at a rate five times faster than microbes outside the slick—accounting in large part for the disappearance of the slick some three weeks after Deepwater Horizon’s Macondo well was shut off.
Cheryl Anderson’s Macondo Oil Spill Update
Posted in accidents, well control incidents, tagged accidents, blowouts, bp, Deepwater Horizon, Gulf of Mexico, macondo, offshore drilling, oil spill on August 1, 2011| 1 Comment »
Cheryl’s update after reviewing the latest reports:
- There is a USCG unified command specific to BP spill residue after storms.
- The tarballs are not considered toxic, just an unattractive nuisance.
- Tarball cleanup on Dauphin Island was halted on May 1 to protect nesting birds.
- BP estimates a total Macondo spill volume of about 4 million bbl as opposed to the government estimate of 4.9 million bbl.
- BP estimates that 850,000 barrels were captured, burned or skimmed off the water.
- 1,260 people remain employed in spill cleanup as of [July 14, 2011], down from a peak of 48,200 a year ago
Articles of interest:
Transocean Releases Macondo Investigation Report
Posted in accidents, well control incidents, tagged accidents, blowouts, BOP, Deepwater Horizon, drilling, Gulf of Mexico, macondo, oil spill, safety, transocean, well control on June 22, 2011| Leave a Comment »
Links
Animation of Transocean’s BOP analysis
Transocean’s BOP Defense:
Forensic evidence from independent post-incident testing by Det Norske Veritas (DNV) and evaluation by the Transocean investigation team confirm that the Deepwater Horizon BOP was properly maintained and did operate as designed. However, it was overcome by conditions created by the extreme dynamic flow, the force of which pushed the drill pipe upward, washed or eroded the drill pipe and other rubber and metal elements, and forced the drill pipe to bow within the BOP. This prevented the BOP from completely shearing the drill pipe and sealing the well.
In other words, Transocean contends that properly maintained BOPE was not up to the task of shutting-in and securing a high-rate well. If true, this finding has significant implications for the offshore industry. I’m looking forward to reading the government’s findings on the BOP failure when the Joint Investigation Team report is issued next month.
Important Macondo Settlement
Posted in accidents, well control incidents, tagged accidents, blowouts, bp, Deepwater Horizon, drilling, float collar, Gulf of Mexico, macondo, Montara, offshore drilling, safety, Weatherford, well control on June 21, 2011| 2 Comments »
BP settled Macondo litigation with Weatherford, manufacturer of the float equipment equipment used in the Macondo well. The failure of this equipment was a key contributing factor in the Macondo blowout. Under the agreement, Weatherford will pay BP $75 million. This money will be applied to the $20 billion Macondo trust fund.
Weatherford is the first of BP’s contractors to formally agree with BP that the entire industry can and should learn from the Deepwater Horizon incident. Accordingly, Weatherford has committed to working with BP to take actions to improve processes and procedures, managerial systems, and safety and best practices in offshore drilling operations. BP and Weatherford will encourage other companies in the drilling industry to join them in this improvement and reform effort.
Comments:
- $75 million seems like a rather modest payment by Weatherford given the magnitude of Macondo damage costs. BP will “indemnify Weatherford for compensatory claims resulting from the accident.” Presumably, Weatherford’s sales agreements provide good legal protection.
- One of the root causes of the Montara blowout was also a float collar failure. That float collar was also supplied by Weatherford. I’m surprised that this common cause and supplier have received almost no attention. Of course, no one has paid much attention to Montara, either before or after Macondo. Had more attention been paid to the Montara inquiry, Macondo might have been avoided. (Note that most of the post-Macondo commentary still implies that deep water is the threat even though Montara was in 80 m of water and the root causes of Macondo were not water depth related).
- When do we learn more about the “improvement and reform effort” described in the quote above?
Western Australia vs. Federal Government Dispute Continues
Posted in accidents, well control incidents, tagged accidents, Australia, blowouts, Montara, offshore drilling, well control, Western Australia on June 18, 2011| Leave a Comment »
Resources Minister Martin Ferguson is determined to establish a single national regulator after the Montara oil spill in the Timor Sea leaked oil and gas condensate for more than two months in 2009.
The WA government is at odds with Mr Ferguson over plans for a national regulator and wants to maintain responsibility for oversight of the industry in the state.
Senator Eggleston and Senator David Bushby said the federal government had introduced the legislation to parliament before concluding ongoing negotiations with the WA government. Herald Sun
Meanwhile, still no news regarding any penalties for Montara operator PTTEP. Will there be none?




