The National Academies of Sciences, Engineering, and Medicine was requested to conduct a peer review of OSRR 1063: Bureau of Safety and Environmental Enforcement Report: Computational Fluid Dynamics Model for Predicting Wellhead Oil-Burning Efficiency at Bench and Intermediate Scales: Interim Report (July 30, 2020), produced by the U.S. Naval Research Laboratory (NRL) and funded by the Bureau of Safety and Environmental Enforcement (BSEE). The work was carried out by an ad hoc committee convened by the National Academies and overseen by the Board on Chemical Sciences and Technology within the Division on Earth and Life Studies. The committee’s peer review encompassed the study methods, the quality of the data informing the study, and the strength of any inferences drawn by the NRL authors; accordingly, this final peer review report focuses on the technical nature of the interim NRL report (OSRR 1063).
CONTEXT FOR THIS PEER REVIEW
BSEE is responsible for permitting, oversight, and enforcement of the laws and regulations governing offshore oil and gas development. Within BSEE, the Oil Spill Preparedness Division (OSPD) is responsible for developing and administering regulations related specifically to the oil and gas industry’s preparedness to contain, recover, and remove oil discharges from facilities operating seaward of the coastline. As part of its permitting authority, BSEE must certify that operators are prepared to respond in the event of a loss of well control and a “worst-case” release.
OSPD is in the process of reviewing a proposal by an independent operator to use wellhead burning to mitigate the effects of a potential well blowout from a gravel island in federal waters off of the North Slope region of Alaska. Because BSEE is charged with ensuring that offshore oil and gas development occurs with minimal environmental impact, it is critical that permitting, oversight, and regulatory decisions be based on the best available science. Therefore, as part of the review process for the independent operator’s proposal, BSEE contracted with NRL to conduct a literature review and provide preliminary technical guidance on the feasibility of wellhead burning as a mitigation method. This review demonstrated insufficient evidence in the published literature to support the proposal that wellhead burning would be efficient enough to minimize unburned oil fallout. BSEE subsequently contracted with NRL to conduct a research program with the primary objective of developing a computational fluid dynamics (CFD) model, with experimental validation at multiple scales (bench scale to intermediate scale), of the burning efficiency of wellhead flames. BSEE asked the National Academies to conduct an independent peer review of NRL’s interim report on the CFD model and experimental validation results.
THE COMMITTEE, ITS TASK, AND ITS APPROACH
The peer review of OSRR 1063: Bureau of Safety and Environmental Enforcement Report: Computational Fluid Dynamics Model for Predicting Wellhead Oil-Burning Efficiency at Bench and Intermediate Scales: Interim Report was conducted by a carefully selected committee of experts appointed by the President of the National Academy of Sciences. The committee included experts in wellhead condition assumptions; flow, soot, and radiation models; droplet injection models, imaging techniques, and characterization; laboratory test validation; temperature measurements; flow regime impact on effluent
plume; wellbore flow impact on plume; fire plume and flame projections; and burn efficiency. See Appendix E for biographical information on the committee members.
To carry out its statement of task (Box 1-1), the committee reviewed NRL’s interim final report, as well as additional background information provided by BSEE, including a detailed list of charge questions for the committee to address (see Appendix A). To conduct a thorough peer review, the committee considered salient information in the published literature. The committee’s deliberations were confidential to avoid any political, special-interest, or sponsor influence. Checks and balances were applied throughout the process to protect the integrity of this report.
To accomplish its task, the committee held four virtual meetings, including two data-gathering sessions that included presentations by NRL and BSEE staff. Both data-gathering sessions were open for the public to access; agendas for those sessions are provided in Appendix C.
Shortly after its official appointment, the committee was provided with the NRL interim report, supplementary materials, and the charge questions supplied by BSEE. Each member was asked to answer the charge questions based upon their findings and interpretation of the interim report. These answers were submitted to staff for compilation and distribution to the full committee prior to its final meeting, when the members reached consensus on a response to each question.
ORGANIZATION OF THE REPORT
Chapter 2 presents the committee’s consensus answers to BSEE’s charge questions. The committee members’ individual anonymized answers to the questions can be found in Appendix B. The committee’s findings and conclusions are presented in Chapter 3. The charge questions were used to guide the committee’s thinking about its Statement of Task, and the committee did not limit its discussions to those questions. After considering the answers to the charge questions, the committee determined what additional information was needed to address each bullet of the Statement of Task.