Government releases DNV's findings on Deepwater Horizon BOP

 (Story updated Mar. 24 with Transocean statement, see 4th paragraph)

Paula Dittrick
OGJ Senior Staff Writer

HOUSTON, Mar. 23 -- Federal officials have released a two-volume report from Det Norske Veritas (DNV) on the forensic examination of the Deepwater Horizon blowout preventer (BOP), and the report recommends additional study be done on the BOP’s failure to close and seal the Macondo well.

On Apr. 20, 2010, a blowout of the Macondo well in about 5,000 ft of water off Louisiana resulted in explosions and fires killing 11 crew members on Transocean Ltd.’s Deepwater Horizon semisubmersible drilling rig. BP PLC operated the Macondo well. A massive oil spill resulted in the Gulf of Mexico.

The Bureau of Ocean Energy Management, Regulation and Enforcement/US Coast Guard Joint Investigation Team released DNV’s report on the BOP, which concluded that off-centered drill pipe prevented the blind shear rams (BSR) from fully closing and sealing the wellbore.

Transocean issued a statement saying, “The findings confirm that the BOP was in proper operating condition and functioned as designed. These results are consistent with the function and pressure tests conducted on the BOP in the days preceding the Macondo well blowout. High-pressure flow from the well created conditions that exceeded the scope of BOP’s design parameters.”

While releasing the report, BOEMRE announced a seventh session of public hearings starting Apr. 4 in New Orleans. The hearings will focus specifically on the BOP forensic examination.

The forensic examination is one aspect of an investigation into the accident and subsequent oil spill. The full investigation report is not expected to be released until sometime this summer, BOEMRE said.

Forensic testing
The report said forces from the flow of the well induced the drill pipe to buckle between the upper annular and the upper variable bore rams (VBR). The drill pipe deflected until it contacted the wellbore just above the BSR.

“This condition would have most likely occurred from the moment the well began flowing and would have remained until either the end conditions changed (change in upper annular or upper VBR state) or the deflected drill pipe was physically altered (sheared), the report said. “The portion of the drill pipe located between the shearing blade surfaces of the BSRs was off center and held in this position by buckling forces.”

Drill pipe became trapped between the ram block faces, preventing the blocks from fully closing and sealing.

“This position of the drill pipe between the upper annular and the upper VBRs led to buckling and bowing of the drill pipe within the wellbore,” the report said.

The BOP examination was completed after the BOP stack was raised from the sea floor on Sept. 4 and transferred to the NASA-Michoud complex in New Orleans. The blind shear, casing shear, and three sets of VBR were removed from the lower section of the BOP and examined both visually and using laser profilometry.

DNV examined the wellbore using high-definition video cameras and used laser profilometry to examine the wellbore and the BSR. The upper and lower annulars in the lower marine riser packer were examined using a high-definition video camera.

Eight segments of drill pipe were recovered, examined, and tested. Two drill pipe segments were recovered from the BOP at Michoud. Three additional segments were recovered from the drilling riser at Michoud. Investigators also examined three other segments of drill pipe that had been previously recovered.

Function testing of the AMF/Deadman autoshear indicated the voltage of the 27-v battery in the blue pod was insufficient to activate the higher-pressure BSR pilot solenoid mounted on the blue pod. Tests of the yellow pod BSR pilot solenoid circuits were inconsistent, the report said.

Recommendations
DNV recommends that industry examine and study potential conditions that could arise in the event of the loss of well control. It suggests numerous studies including:

• Effects of the flow of the well fluids on BOP components and various tubulars that might be present.

• Effects that could arise from the tubulars being fixed or constrained within the components of a BOP.

• Ability of the BOP components to complete their intended design or function under these conditions.

DNV also recommended industry study the ability of shear rams to completely cut tubular and seal the well regardless of the tubulars position within the wellbore.

“The findings of these studies should be considered and addressed in the design of future BOPs and the need for modifying current BOPs to address these findings,” the report said.

DNV also recommended industry examine and study the potential effects or results that closing of the annulars or closing of the VBRs could have on the BOP stack, including an evaluation of how elastic buckling of tubulars could adversely affect the ability to regain control of the well.

Contact Paula Dittrick at paulad@ogjonline.com.

Related Articles

PHMSA proposes pipeline accident notification regulations

07/02/2015 The US Pipeline and Hazardous Materials Safety Administration has proposed new federal oil and gas pipeline accident and notification regulations. ...

FourPoint Energy to acquire Anadarko basin assets from Chesapeake

07/02/2015 FourPoint Energy LLC, a privately owned Denver company, plans to acquire oil and gas assets from Chesapeake Energy Corp. subsidiaries Chesapeake Ex...

Puma Energy completes purchase of Murco’s UK refinery, terminals

07/02/2015 Singapore-based Puma Energy Group Pte. has completed its purchase of UK midstream and downstream assets from Murco Petroleum Ltd., a subsidiary of ...

BP to settle federal, state Deepwater Horizon claims for $18.7 billion

07/02/2015 BP Exploration & Production Inc. has agreed in principle to settle all federal and state claims arising from the 2010 Deepwater Horizon inciden...

MARKET WATCH: NYMEX oil prices plummet on crude inventory build, Iran deadline extension

07/02/2015 Oil prices plummeted more than $2/bbl July 1 to settle at a 2-month low on the New York market after a weekly government report showed the first ri...

API to issue recommended practice to address pipeline safety

07/01/2015 The American Petroleum Institute expects to issue a new recommended practice in another few weeks that addresses pipeline safety issues, but the tr...

Shell Midstream Partners takes interest in Poseidon oil pipeline

07/01/2015 Shell Midstream Partners LP has completed its acquisition of 36% equity interest in Poseidon Oil Pipeline Co. LLC from Equilon Enterprises LLC, a s...

Shell makes FID on Appomattox deepwater development in Gulf of Mexico

07/01/2015 Royal Dutch Shell PLC has taken a final investment decision (FID) on the Appomattox deepwater development, authorizing construction and installatio...

MARKET WATCH: Oil prices decline as US crude inventories post first gain in 9 weeks

07/01/2015 Oil prices on July 1 surrendered much of their gains from the day before after the release of a government report showing the first rise in US crud...
White Papers

2015 Global Engineering Information Management Solutions Competitive Strategy Innovation and Leadership Award

The Frost & Sullivan Best Practices Awards recognise companies in a variety of regional and global...
Sponsored by

Three Tips to Improve Safety in the Oil Field

Working oil fields will always be tough work with inherent risks. There’s no getting around that. Ther...
Sponsored by

Pipeline Integrity: Best Practices to Prevent, Detect, and Mitigate Commodity Releases

Commodity releases can have catastrophic consequences, so ensuring pipeline integrity is crucial for p...
Sponsored by

AVEVA’s Digital Asset Approach - Defining a new era of collaboration in capital projects and asset operations

There is constant, intensive change in the capital projects and asset life cycle management. New chall...
Sponsored by

Transforming the Oil and Gas Industry with EPPM

With budgets in the billions, timelines spanning years, and life cycles extending over decades, oil an...
Sponsored by

Asset Decommissioning in Oil & Gas: Transforming Business

Asset intensive organizations like Oil and Gas have their own industry specific challenges when it com...
Sponsored by

Squeezing the Green: How to Cut Petroleum Downstream Costs and Optimize Processing Efficiencies with Enterprise Project Portfolio Management Solutions

As the downstream petroleum industry grapples with change in every sector and at every level, includin...
Sponsored by

7 Steps to Improve Oil & Gas Asset Decommissioning

Global competition and volatile markets are creating a challenging business climate for project based ...
Sponsored by
Available Webcasts

On Demand

OGJ's Midyear Forecast 2015

Fri, Jul 10, 2015

This webcast is to be presented by OGJ Editor Bob Tippee and Senior Economic Editor Conglin Xu.  They will summarize the Midyear Forecast projections in key categories, note important changes from January’s forecasts, and examine reasons for the adjustments.

register:WEBCAST


Predictive Analytics in your digital oilfield - Optimize Production Yield and Reduce Operational Costs

Tue, Jul 7, 2015

Putting predictive analytics to work in your oilfield can help you anticipate failures, plan and schedule work in advance, eliminate emergency work and catastrophic failures, and at the same time you can optimize working capital and improve resource utilization.  When you apply analytic capabilities to critical production assets it is possible to reduce non-productive time and increase your yield.

Learn how IBM's analytics capabilities can be applied to critical production assets with the goal of reducing non-productive time, increasing yield and reducing operations costs.

register:WEBCAST


Cognitive Solutions for Upstream Oil and Gas

Fri, Jun 12, 2015

The oil & gas sector is under pressure on all sides. Reserves are limited and it’s becoming increasingly expensive to find and extract new resources. Margins are already being squeezed in an industry where one wrong decision can cost millions. Analyzing data used in energy exploration can save millions of dollars as we develop ways to predict where and how to extract the world’s massive energy reserves.

This session with IBM Subject Matter Experts will discuss how IBM Cognitive Solutions contribute to the oil and gas industry using predictive analytics and cognitive computing, as well as real time streaming for exploration and drilling.

register:WEBCAST


The Alternative Fuel Movement: Four Need-to-Know Excise Tax Complexities

Thu, Jun 4, 2015

Discussion on how to approach, and ultimately embrace, the alternative fuel market by pulling back the veil on excise tax complexities. Taxes may be an aggravating part of daily operations, but their accuracy is crucial in your path towards business success.

register:WEBCAST


Emerson Micro Motion Videos

Careers at TOTAL

Careers at TOTAL - Videos

More than 600 job openings are now online, watch videos and learn more!

 

Click Here to Watch

Other Oil & Gas Industry Jobs

Search More Job Listings >>
Stay Connected