MC-20 Science

STUDY DOCUMENTS RELEASE OF REMNANT HYDROCARBONS FROM SEDIMENT AND FINDS NO DEFINITIVE EVIDENCE OF ACTIVE RESERVOIR DISCHARGE AT MC-20 SITE IN GULF OF MEXICO

Calls upon responsible Federal Agencies to engage the National Academies of Sciences, Engineering and Medicine

FOR IMMEDIATE RELEASE:  May 11, 2020

New Orleans, La. – A peer-reviewed Study “Harnessing a decade of data to inform future decisions: Insights into the ongoing hydrocarbon release at Taylor Energy’s Mississippi Canyon 20 site,” was published today in Marine Pollution Bulletin.   A copy of the paper is available at: https://authors.elsevier.com/sd/article/S0025-326X(20)30174-0. 

The response to the 2004 toppling and partial burial of the MC-20 platform is the longest in history.  The scope and complexity of actions taken at MC-20 are unprecedented, yet after 15 years, no consensus has emerged as to the release mechanism or the path to a permanent resolution. 

The purpose of the Marine Pollution Bulletin paperis to inform ongoing response options by providing a better understanding of release dynamics. The scientists relied upon prior research developed under the auspices of the U.S. Coast Guard-led Unified Command.

Based on chemical forensics, the scientists found that surface sheens sampled in 2017 contain hydrocarbons previously entombed in sediments before the last well intervention in 2011. 

“We specifically test and refute the hypothesis that surface sheens originate as discharge from one or two homogenous reservoirs, and instead find that the evidence supports release of multiple, chemically-distinct oil groups including exhumation of hydrocarbons trapped in the sediment,” conclude the authors.

In addition, the authors conclude there is “no definitive evidence of hydrocarbon discharge directly from a reservoir.”

The authors maintain “the benefit and risk associated with additional unconventional well interventions has been and remains at the forefront of the MC-20 response and should incorporate the observations from this research.”

Authors’ Recommendations

In the paper the authors recommend independent experts evaluate scientific uncertainties and advanced engineering solutions: “Given the challenging scientific and technical nature of this problem and the stalled progress, we call on the responsible federal agencies to capitalize on the respite and opportunity afforded by active containment and initiate a fast-track study by the National Academies of Sciences, Engineering and Medicine to develop response options”.

They go on to suggest “leveraging ongoing collection activities to assess release dynamics,” saying, “the combination of capture rate, chemical composition, temperature, and salinity data could be invaluable for interpreting the dynamic behavior of oil and gas subseafloor and inform possible and appropriate long-term solutions. Samples and data from the collection system should also be made available to parties outside the response, which is not present [Coast Guard] practice.”

The authors warn, “A major hurdle for any path forward is managing the liability associated with a failed outcome that results in the release of more oil, damage to property, or worse, causes harm to responders. These are genuine concerns given the challenging and complex environment at MC-20.”

About the Study

The paper was authored by a team of eight scientists who have been studying the MC-20 site for over a decade:

  • Wade L. Bryant, CK Associates, Baton Rouge, LA
  • Richard Camilli, Navistry Corporation, Jackson, WY
  • G. Burch Fisher, Earth Research Institute, University of California, Santa Barbara, CA
  • Edward V. Overton, Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA
  • Christopher M. Reddy, Makepeace Environmental Solutions LLC, Woods Hole, MA
  • Danny Reible, Department of Civil and Environmental Engineering, Texas Tech University, Lubbock, TX
  • Robert F. Swarthout, Department of Chemistry, Appalachian State University, Boone, NC
  • David L. Valentine, Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA

Funding for the Study was provided by Taylor Energy Company, the federally-designated “Responsible Party” for the MC-20 incident. 

Marine Pollution Bulletin is concerned with the rational use of maritime and marine resources in estuaries, the seas and oceans, as well as with documenting marine pollution and introducing new forms of measurement and analysis. A wide range of topics are discussed as news, comment, reviews and research reports, not only on effluent disposal and pollution control, but also on the management, economic aspects and protection of the marine environment in general.

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The article was published in Marine Pollution Bulletin, and it can also be found online, with additional information about the science of MC-20, at MC20Science.com.