Macondo Well
Deepwater Horizon
BlowoutLESSONS FOR IMPROVING
OFFSHORE DRILLING SAFETYCommittee on the Analysis of Causes of the
Deepwater Horizon Explosion, Fire, and Oil Spill to
Identify Measures to Prevent Similar Accidents in the FutureMarine Board
Board on Environmental Studies and Toxicology
NATIONAL ACADEMY OF ENGINEERING AND
NATIONAL RESEARCH COUNCIL
OF THE NATIONAL ACADEMIES
THE NATIONAL ACADEMIES PRESS
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This project was supported by Contract No. N10PC18384 between the National Academy of Sciences and the U.S. Department of the Interior. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the organizations or agencies that provided support for this project.
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THE NATIONAL ACADEMIES
Advisers to the Nation on Science, Engineering, and Medicine
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COMMITTEE ON THE ANALYSIS OF CAUSES OF THE DEEPWATER HORIZON EXPLOSION, FIRE, AND OIL SPILL TO IDENTIFY MEASURES TO PREVENT SIMILAR ACCIDENTS IN THE FUTURE
Members
DONALD C. WINTER (Chair), University of Michigan, Ann Arbor
PAUL M. BOMMER, University of Texas at Austin
CHRYSSOSTOMOS CHRYSSOSTOMIDIS, Massachusetts Institute of Technology, Cambridge
DAVID E. DANIEL, University of Texas at Dallas
THOMAS J. ECCLES, United States Navy, Washington, D.C.
EDMUND P. GIAMBASTIANI, JR., United States Navy (retired), Warwick, Maryland
DAVID A. HOFMANN, University of North Carolina at Chapel Hill
ROGER L. MCCARTHY, McCarthy Engineering, Palo Alto, California
NAJMEDIN MESHKATI, University of Southern California, Los Angeles
KEITH K. MILLHEIM, Strategic Worldwide, LLC, The Woodlands, Texas (Resigned November 28, 2011, prior to completion of the committee’s report)
M. ELISABETH PATÉ-CORNELL, Stanford University, Stanford, California
ROBERT F. SAWYER, University of California at Berkeley
JOCELYN E. SCOTT, DuPont Engineering, Facilities and Real Estate, Wilmington, Delaware
ARNOLD F. STANCELL, Georgia Institute of Technology, Greenwich, Connecticut
MARK D. ZOBACK, Stanford University, Stanford, California
Staff
RAYMOND A. WASSEL, Project Director
MARINE BOARD
MICHAEL S. BRUNO (Chair), Stevens Institute of Technology, Hoboken, New Jersey
THOMAS M. LESCHINE (Vice Chair), University of Washington, Seattle
STEVEN R. BARNUM, Hydrographic Consultation Services, Suffolk, Virginia
JERRY A. BRIDGES, Virginia Port Authority, Norfolk
MARY R. BROOKS, Dalhousie University, Halifax, Nova Scotia, Canada
JAMES C. CARD, Maritime Consultant, The Woodlands, Texas
STEPHEN M. CARMEL, Maersk Line Limited, Norfolk, Virginia
EDWARD N. COMSTOCK, Raytheon Company, Sudbury, Massachusetts
STEPHAN TONI GRILLI, University of Rhode Island, Narragansett
DOUGLAS J. GRUBBS, Crescent River Port Pilots Association, Metairie, Louisiana
FREDERICK J. HARRIS, General Dynamics, San Diego, California
JUDITH HILL HARRIS, City of Portland, Maine
JOHN R. HEADLAND, Moffatt & Nichol Engineers, New York, New York
JOHN M. HOLMES, Port of Los Angeles, San Pedro, California
DONALD LIU, Marine Consultant, Willis, Texas
RICHARD S. MERCIER, Texas A&M University, College Station
EDMOND J. MORAN, JR., Moran Towing Corporation, New Canaan, Connecticut
ALI MOSLEH, University of Maryland, College Park
GEORGE BERRYMAN NEWTON, QinetiQ North America, Marstons Mills, Massachusetts
PETER K. VELEZ, Shell International Exploration and Production, Inc., Houston, Texas
JOHN WILLIAM WAGGONER, HMS Global Maritime, New Albany, Indiana
TRANSPORTATION RESEARCH BOARD 2011 EXECUTIVE COMMITTEE OFFICERS
NEIL J. PEDERSEN (Chair), Administrator, Maryland State Highway Administration (retired), Baltimore
SANDRA ROSENBLOOM (Vice Chair), Professor of Planning, University of Arizona, Tucson
C. MICHAEL WALTON (Division Chair for NRC Oversight), Ernest H. Cockrell Centennial Chair in Engineering, University of Texas, Austin
ROBERT E. SKINNER, JR. (Executive Director), Transportation Research Board
BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY
Members
ROGENE F. HENDERSON (Chair), Lovelace Respiratory Research Institute, Albuquerque, New Mexico
PRAVEEN AMAR, Clean Air Task Force, Boston, Massachusetts
TINA BAHADORI, American Chemistry Council, Washington, D.C.
MICHAEL J. BRADLEY, M.J. Bradley & Associates, Concord, Massachusetts
JONATHAN Z. CANNON, University of Virginia, Charlottesville
GAIL CHARNLEY, HealthRisk Strategies, Washington, D.C.
FRANK W. DAVIS, University of California, Santa Barbara
RICHARD A. DENISON, Environmental Defense Fund, Washington, D.C.
CHARLES T. DRISCOLL, JR., Syracuse University, New York
H. CHRISTOPHER FREY, North Carolina State University, Raleigh
RICHARD M. GOLD, Holland & Knight, LLP, Washington, D.C.
LYNN R. GOLDMAN, George Washington University, Washington, D.C.
LINDA E. GREER, Natural Resources Defense Council, Washington, D.C.
WILLIAM E. HALPERIN, University of Medicine and Dentistry of New Jersey, Newark
PHILIP K. HOPKE, Clarkson University, Potsdam, New York
HOWARD HU, University of Michigan, Ann Arbor
SAMUEL KACEW, University of Ottawa, Ontario, Canada
ROGER E. KASPERSON, Clark University, Worcester, Massachusetts
THOMAS E. MCKONE, University of California, Berkeley
TERRY L. MEDLEY, E.I. du Pont de Nemours & Company, Wilmington, Delaware
JANA MILFORD, University of Colorado at Boulder
FRANK O’DONNELL, Clean Air Watch, Washington, D.C.
RICHARD L. POIROT, Vermont Department of Environmental Conservation, Waterbury
KATHRYN G. SESSIONS, Health and Environmental Funders Network, Bethesda, Maryland
JOYCE S. TSUJI, Exponent Environmental Group, Bellevue, Washington
Senior Staff
JAMES J. REISA, Director
DAVID J. POLICANSKY, Scholar
RAYMOND A. WASSEL, Senior Program Officer for Environmental Studies
ELLEN K. MANTUS, Senior Program Officer for Risk Analysis
SUSAN N.J. MARTEL, Senior Program Officer for Toxicology
EILEEN N. ABT, Senior Program Officer
RUTH E. CROSSGROVE, Senior Editor
MIRSADA KARALIC-LONCAREVIC, Manager, Technical Information Center
RADIAH ROSE, Manager, Editorial Projects
DEDICATION
We dedicate this report to the memory of the eleven people who lost their lives on board the Deepwater Horizon on April 20, 2010.
Jason Christopher Anderson
Aaron Dale Burkeen
Donald Neal Clark
Stephen Ray Curtis
Gordon Lewis Jones
Roy Wyatt Kemp
Karl Dale Kleppinger, Jr.
Keith Blair Manuel
Dewey Allen Revette
Shane Michael Roshto
Adam Taylor Weise
Preface
The blowout of the Macondo well on April 20, 2010, led to enormous consequences for the individuals involved in the drilling operations and for their families. Eleven workers on the Deepwater Horizon drilling rig lost their lives, and 16 others were seriously injured. There were also enormous consequences for the companies involved in the drilling operations, to the Gulf of Mexico environment, and to the economy of the region and beyond. The flow continued for nearly 3 months before the well could be completely killed, during which time nearly 5 million barrels of oil spilled into the gulf. The economic consequences of the event were felt almost immediately and became more widespread over time. A moratorium on drilling activities was put in place throughout the gulf, and commercial fishing was halted in much of the region. The total economic impact is in the tens of billions of dollars. The long-term ecological impact will likely take many years to measure. This was truly a “spill of national significance,”1 and international efforts to learn from this disaster have been spurred.
Shortly after the event, the National Academy of Engineering (NAE) and the National Research Council (NRC) were asked by the Secretary of the Interior to form a committee to examine the probable causes of the Deepwater Horizon explosion, fire, and oil spill and to identify means for preventing similar harm in the future. The committee benefited from a focused and well-defined scope, which excluded several issues such as the extensive response and remediation efforts (see Appendix A). Nonetheless, NAE and NRC wanted to ensure that the committee had not only the requisite expertise appropriate to a deepwater drilling accident but also the breadth needed to ensure that the root causes of the incident and appropriate corrective actions could be identified. Consequently, a committee of 15 members was assembled, which provided expertise in geophysics, petroleum engineering, marine systems, accident investigations, safety systems, risk analysis, human factors, and organizational behavior (see the biographical information at the end of this document).
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1Designation made by the Secretary of Homeland Security on April 29, 2010.
The committee was able to take advantage of other investigations occurring at the same time, such as the Marine Board of Investigation (MBI), convened by the U.S. Coast Guard (USCG) and the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE—formerly the Minerals Management Service). Members of the committee observed the MBI hearings and reviewed documentation submitted to the board. Similarly, committee members observed hearings of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling and the U.S. Chemical Safety Board. The committee conducted its own public meetings to hear presentations from regulators (USCG, BOEMRE, and the Republic of the Marshall Islands—the flag state), the American Petroleum Institute, the American Bureau of Shipping, and industry (see Appendix B).
The information provided to the committee by industry was constrained by the legal environment generated by the MBI, the investigation of the Department of Justice, and the prospect of multiple matters of civil litigation involving tens of billions of dollars. However, some of the companies involved in the Deepwater Horizon incident participated in the committee’s public meetings and submitted material in writing, including several corporate investigative reports. BP, Halliburton, and Transocean provided information to the committee. Cameron, manufacturer of the Deepwater Horizon’s blowout preventer (BOP), provided some material but declined to make a presentation on the Deepwater Horizon BOP.
The committee also benefited from good support by USCG, which facilitated access to recovered items from Deepwater Horizon (lifeboats, riser, drill pipe, and BOP). The BOP assessment was greatly aided by the forensic work performed by Det Norske Veritas (DNV) and reported by DNV (2011a, 2011b). However, the committee was unable to obtain results of Phase 2 testing of the Deepwater Horizon BOP led by BP. The results are maintained under protective orders by the courts supervising related litigation matters.
The committee received support from a number of industrial organizations that were not directly involved in the Macondo well–Deepwater Horizon incident, which improved its understanding of the various standards and practices of the industry. Of note, Shell provided access both to its Real-Time Operations Center in Houston, Texas, and to the Deepwater Nautilus, the sister ship to Deepwater Horizon. Hydril similarly provided access to its BOP design, production, and test facilities. The committee also visited Wild Well Control School in Houston to improve its understanding of the training provided to drilling personnel. In addition to the industry inputs provided through corporate channels, the committee was able to obtain inputs from industry personnel reflected in written summaries provided by the Society of Petroleum Engineers and the International Association of Drilling Contractors. The summaries were prepared with the prior understanding that none of the input would be attributed to specific individuals. To obtain a better understanding of alternative regulatory approaches, committee members visited the Petroleum Safety Authority of Nor-
way, SINTEF (Stiftelsen for Industriell og Teknisk Forskning), the Norwegian Oil Industry Association, and the U.K. Health and Safety Executive.
The scope and depth of the information available to the committee enabled it to develop findings and informed observations concerning the probable causes (both direct and root causes) of the incident. The information also enabled the committee to develop a series of recommendations that it believes will reduce the likelihood and impact of any future well control incidents. This final report documents the major findings, observations, and recommendations developed by the committee during its study.2 The report does not attempt to assign responsibility for the incident to specific individuals or corporations, nor does it attempt to make a systematic assessment of the extent to which the parties involved complied with applicable regulations. Such matters were deemed to be appropriately addressed by the MBI.
The committee notes that several of its recommendations reinforce steps already taken to strengthen regulatory practices in the aftermath of this incident. These are steps in the right direction, which need to be built on in a timely manner to ensure that the risks associated with this critical industry are minimized and that the public trust in both industry operations and regulatory processes is restored. Many challenges beyond those addressed in this report must be faced to revitalize the regulatory process. In particular, the administration and Congress will need to provide the funding and flexibility in hiring practices that will allow the Bureau of Safety and Environmental Enforcement (BSEE)3 to enhance its capability and capacity.
There have been positive indications regarding industry’s recognition of the need for change, as well. Notable have been the formation and funding of additional response capabilities, such as the Marine Well Containment Company. That said, the companies involved in the Macondo well-Deepwater Horizon incident have the added challenge of ensuring that positions taken to defend against civil liabilities and potential criminal charges do not inhibit their timely recognition of the need to change their internal processes and the manner in which the many parties to this industry (operating companies, drilling contractors, and service companies) all work together.
The need to maintain domestic sources of oil is great, but so is the need to protect the lives of those who work in this industry and to protect the Gulf of Mexico and the many other industries that depend on it. The oil and gas industry
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2The committee issued an interim letter report on November 16, 2010, which presented preliminary findings and observations concerning key factors and decisions that may have contributed to the blowout of the Macondo well. The committee also provided a letter to BOEMRE on September 17, 2010, which identified potential approaches for use in conducting forensic analyses of the Deepwater Horizon BOP.
3On October 1, 2011, BOEMRE split into two entities. BSEE is currently the federal entity responsible for safety and environmental oversight of offshore oil and gas operations internal processes and the manner in which the many parties to this industry (operating companies, drilling contractors, and service companies) work together.
is robust and capable of improving offshore drilling safety; it employs many experienced personnel and utilizes many impressive technologies. Similarly, there are many dedicated and capable individuals in the various regulatory agencies responsible for overseeing the industry who can make further safety improvements. There is no reason why the diligent application of these multifold capabilities toward strengthening system safety should not significantly reduce the likelihood and consequences of any future loss of well control in the Gulf of Mexico.
Donald C. Winter, Chair
Committee on the Analysis of Causes of the Deepwater
Horizon Explosion, Fire, and Oil Spill to Identify
Measures to Prevent Similar Accidents in the Future
Acknowledgments
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise in accordance with procedures approved by NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that assist the authors and NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We thank the following individuals for their review of this report: Benton F. Baugh, Radoil Inc., Houston, Texas; Robert Bea, University of California, Berkeley (emeritus); Michael J. Burke, Tulane University, New Orleans, Louisiana; Vice Admiral James C. Card (USCG, retired), The Woodlands, Texas; Elmer Danenberger III, independent consultant, Reston, Virginia; Chan Gill, independent consultant, Avondale, Arizona; Richard Hartley, B&W Pantex, Amarillo, Texas; Trevor O. Jones, ElectroSonics Medical Inc., Cleveland, Ohio; Rear Admiral Malcolm MacKinnon III (U.S. Navy, retired), MSCL LLC, Alexandria, Virginia; Erik B. Nelson, independent consultant, Houston, Texas; Robin Pitblado, Det Norske Veritas (U.S.A.), Inc., Katy, Texas; Christopher Ranger, Ranger Consultants, Ltd., Ayrshire, Scotland; Frank J. Schuh, Drilling Technology, Inc., Plano, Texas; Richard Sears, Leading Energy Now, Houston, Texas; and A. Dan Tarlock, Chicago Kent College of Law, Chicago, Illinois.
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the committee’s conclusions or recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by Robert A. Frosch, Harvard University, Cambridge, Massachusetts, and by C. Michael Walton, University of Texas, Austin. Appointed by NRC, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.
The work of the committee was assisted by three consultants. Michael Griffes, Alexandria, Virginia, and Peter Johnson, Washington, D.C., facilitated information-gathering activities. Stephen Kemp, Marine & Process Controls LLC, Whitmore Lake, Michigan, provided analysis of the Deepwater Horizon control and alarm systems.
This project was overseen by the Marine Board, a component of the NRC’s Transportation Research Board (TRB), with support from the Board on Environmental Studies and Toxicology of the NRC’s Division on Earth and Life Studies.
Raymond Wassel managed the study under the guidance of the committee and the supervision of Stephen Godwin, Director, Studies and Special Programs, TRB. Beverly Huey and Mirsada Karalic-Loncarevic provided scientific and technical information. Norman Solomon edited the report; Jennifer Weeks prepared the prepublication manuscript, under the supervision of Javy Awan, Director of Publications, TRB. Radiah Rose assisted in preparing the prepublication manuscript and the final published version. Mark Hutchins and Orin Luke arranged meetings and provided logistical communications to the committee. In addition, Keri Schaffer helped with gathering and compiling background information.
Abbreviations
ABS | American Bureau of Shipping |
ALARP | as low as reasonably practicable |
AMF | automatic mode function |
AoC | acknowledgment of compliance |
API | American Petroleum Institute |
ASRS | Aviation Safety Reporting System |
BOEMRE | Bureau of Ocean Energy Management, Regulation, and Enforcement |
BOP | blowout preventer |
BSR | blind shear ram |
BSEE | Bureau of Safety and Environmental Enforcement |
CAIB | Columbia Accident Investigation Board |
CCPS | Center for Chemical Process Safety |
CDC | Centers for Disease Control and Prevention |
CGD | combustible gas detector |
CSB | U.S. Chemical Safety Board |
CSR | casing shear ram |
DHSG | Deepwater Horizon Study Group |
DNV | Det Norske Veritas |
DoD | U.S. Department of Defense |
DOI | U.S. Department of the Interior |
ECD | equivalent circulating density |
EDS | emergency disconnect system |
EIA | U.S. Energy Information Administration |
EMW | equivalent mud window |
EPA | U.S. Environmental Protection Agency |
EPRI | Electric Power Research Institute |
E&P | exploration and production |
ESD | emergency shutdown |
FAA | Federal Aviation Administration |
FBI | Federal Bureau of Investigation |
FS | flag state |
GAO | U.S. General Accounting Office |
HSE | Health and Safety Executive of the United Kingdom |
IACS | integrated alarm and control system |
IADC | International Association of Drilling Contractors |
IAEA | International Atomic Energy Agency |
IBOP | internal blowout preventer |
LCM | lost circulation material |
LMRP | lower marine riser package |
MBI | Marine Board of Investigation |
MGS | mud–gas separator |
MMS | Minerals Management Service |
MODU | mobile offshore drilling unit |
MUX | multiplexer |
MWCC | Marine Well Containment Company |
NAE | National Academy of Engineering |
NEI | Nuclear Energy Institute |
NOAA | National Oceanic and Atmospheric Administration |
NPC | National Petroleum Council |
NRC | National Research Council |
NTSB | National Transportation Safety Board |
OECD | Organisation for Economic Cooperation and Development |
OIM | offshore installation manager |
OLF | Norwegian Oil Industry Association |
ppg | pounds per gallon |
Presidential Commission | National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling |
PSA | Petroleum Safety Authority of Norway |
ROV | remotely operated vehicle |
SEMS | Safety and Environmental Management Systems |
SINTEF | Stiftelsen for Industriell og Teknisk Forskning |
SPE | Society of Petroleum Engineers |
SUBSAFE | U.S. Navy's Submarine Safety Program |
TSA | Transportation Security Administration |
USCG | U. S. Coast Guard |
U.S. NRC | U.S. Nuclear Regulatory Commission |
VBR | variable bore ram |
WCID | well construction interface document |
Contents
Challenges in Designing and Constructing Offshore Wells
Several Past Accidents Caused by Blowouts
History of Macondo Well Before the Blowout
Committee’s Approach to Its Task
2 Well Design and Construction
Overview of the Macondo Well Plan
BOP System for Deepwater Horizon
4 Mobile Offshore Drilling Units
Regulation of U.S. Offshore Drilling Before the Macondo Well Blowout
DOI’s Safety and Environmental Management Systems
Goal-Oriented Risk Management Regulatory Systems
APPENDICES
C Findings, Observations, and Recommendations
Study Committee Biographical Information
BOXES, FIGURES, AND TABLES
BOX
1-1 Reports of Other Macondo Well–Deepwater Horizon Investigations
FIGURES
2-1 Original wellbore architecture planned for Macondo well
2-2 Final wellbore architecture for Macondo well
2-5 Planned cement location and likely cement location after pumping
2-6 Calculated foam density versus depth during pumping
2-7 Uncontaminated cement compressive strength tests (DP = differential pressure)
2-8 Float collar with flapper valves and differential fill tube
3-1 Deepwater Horizon BOP port side
3-2 Sketch of intended nominal operation of BSR in the Macondo well
3-4 Macondo well blowout timeline
3-5 Finite element analysis model of BSR blade surfaces and off-center drill pipe
4-1 Basic dimensions of the Deepwater Horizon rig while drilling
4-2 Illustration of the main deck of the Deepwater Horizon
5-1 Selected major petroleum mergers (1996–2002)
TABLES
2-1 Chevron Data to Illustrate the Effect of Mud Contamination on Cement Compressive Strength
6-1 Offshore Drilling Operations and Relevant Federal Agencies
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