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

Victoria extends drilling, fracing ban

01/30/2015 The new Victorian Labor government of premier Daniel Andrews has extended the coal seam gas (CSG) exploration and hydraulic fracturing ban in the s...

Oxy cuts capital budget by a third

01/30/2015 In the midst of falling oil prices, Occidental Petroleum Corp., Houston, expects to reduce its total capital spending for 2015 to $5.8 billion from...

Gas-turbine units in transit to Vostochno-Messoyakhskoye field

01/28/2015 JSC Gazprom Neft reported that six gas-turbine power units are in transit to Vostochno-Messoyakhskoye field in the Yamalo-Nenetsk Autonomous Region.

Eni lets $2.54-billion contract for Ghana FPSO

01/28/2015 Eni SPA unit Eni Ghana Exploration & Production Ltd. has let a $2.54-billion contract to Malaysia’s Yinson Holdings Bhd. for the chartering, op...

Chevron, BP, ConocoPhillips join to explore, appraise Gulf of Mexico leases

01/28/2015 Chevron Corp. subsidiary Chevron USA Inc., BP PLC unit BP Exploration & Production Inc., and ConocoPhillips Co. have pledged to work together t...

Carrizo cuts drilling, completion spending by 35%

01/27/2015 Carrizo Oil & Gas Inc., Houston, is cutting its drilling and completion capital expenditure plan for the year by 35% to $450-470 million, but e...

Stone Energy lets pipe supply, installation contracts for Amethyst field

01/27/2015 Stone Energy Corp., Lafayette, La., has let flexible pipe supply and installation contracts to Technip SA for Amethyst field on Mississippi Canyon ...

Hess cuts capital budget by 16% to $4.7 billion

01/27/2015 Hess Corp. has set a capital budget of $4.7 billion for 2015, down 16% from $5.6 billion spent last year. The company at the beginning of 2014 repo...

OGUK: Push to ban fracing in UK ‘ill-informed’

01/26/2015 The House of Commons Environmental Audit Committee’s proposed amendment to the infrastructure bill that would introduce a moratorium on hydraulic f...
White Papers

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

The impact of aging infrastructure in process manufacturing industries

Process manufacturing companies in the oil and gas, utilities, chemicals and natural resource industri...
Sponsored by

What is System Level Thermo-Fluid Analysis?

This paper will explain some of the fundamentals of System Level Thermo-Fluid Analysis and demonstrate...

Accurate Thermo-Fluid Simulation in Real Time Environments

The crux of any task undertaken in System Level Thermo-Fluid Analysis is striking a balance between ti...

6 ways for Energy, Chemical and Oil and Gas Companies to Avert the Impending Workforce Crisis

As many as half of the skilled workers in energy, chemical and oil & gas industries are quickly he...
Sponsored by
Available Webcasts

On Demand

Global LNG: Adjusting to New Realities

Fri, Mar 20, 2015

Oil & Gas Journal’s March 20, 2015, webcast will look at how global LNG trade will be affected over the next 12-24 months by falling crude oil prices and changing patterns and pressures of demand. Will US LNG production play a role in balancing markets? Or will it add to a growing global oversupply of LNG for markets remote from easier natural gas supply? Will new buyers with marginal credit, smaller requirements, or great need for flexibility begin to look attractive to suppliers? How will high-cost, mega-projects in Australia respond to new construction cost trends?

register:WEBCAST


US Midstream at a Crossroads

Fri, Mar 6, 2015

Oil & Gas Journal’s Mar. 6, 2015, webcast will focus on US midstream companies at an inflection point in their development in response to more than 6 years shale oil and gas production growth. Major infrastructure—gas plants, gathering systems, and takeaway pipelines—have been built. Major fractionation hubs have expanded. Given the radically changed pricing environment since mid-2014, where do processors go from here? What is the fate of large projects caught in mid-development? How to producers and processors cooperate to ensure a sustainable and profitable future? This event will serve to set the discussion table for the annual GPA Convention in San Antonio, Apr. 13-16, 2015.

This event is sponsored by Leidos Engineering.

register:WEBCAST


The Future of US Refining

Fri, Feb 6, 2015

Oil & Gas Journal’s Feb. 6, 2015, webcast will focus on the future of US refining as various forces this year conspire to pull the industry in different directions. Lower oil prices generally reduce feedstock costs, but they have also lowered refiners’ returns, as 2015 begins with refined products priced at lows not seen in years. If lower per-barrel crude prices dampen production of lighter crudes among shale plays, what will happen to refiners’ plans to export more barrels of lighter crudes? And as always, refiners will be affected by government regulations, particularly those that suppress demand, increase costs, or limit access to markets or supply.

register:WEBCAST


Oil & Gas Journal’s Forecast & Review/Worldwide Pipeline Construction 2015

Fri, Jan 30, 2015

The  Forecast & Review/Worldwide Pipeline Construction 2015 Webcast will address Oil & Gas Journal’s outlooks for the oil market and pipeline construction in a year of turbulence. Based on two annual special reports, the webcast will be presented by OGJ Editor Bob Tippee and OGJ Managing Editor-Technology Chris Smith.
The Forecast & Review portion of the webcast will identify forces underlying the collapse in crude oil prices and assess prospects for changes essential to recovery—all in the context of geopolitical pressures buffeting the market.

register:WEBCAST


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