While the public is generally aware of the use of hydraulic fracturing for unconventional resource development onshore, it is less familiar with the well completion and stimulation technologies used in offshore operations, including hydraulic fracturing, gravel packs, “frac-packs,” and acid stimulation.1 Just as onshore technologies have improved, these well completion and stimulation technologies for offshore hydrocarbon resource development have progressed over many decades. To increase public understanding of these technologies, the National Academies’ Roundtable on Unconventional Hydrocarbon Development established a planning committee to organize and convene a workshop on Offshore Well Completion and Stimulation: Using Hydraulic Fracturing and Other Technologies on October 2-3, 2017, in Washington, DC. This workshop examined the unique features about operating in the U.S. offshore environment, including well completion and stimulation technologies, environmental considerations and concerns, and health and safety management. Participants from across government, industry, academia, and nonprofit sectors shared their perspectives on operational and regulatory approaches to mitigating risks to the environment and to humans in the development of offshore resources (see Box 1.1 for workshop Statement of Task). Specifically, the panelists, speakers, and audience drew on their collective expertise to consider the following questions:
- What is the purpose of these technologies in the offshore environment?
- How are these technologies different from those onshore?
- How does the geology of each environment impact the use of these technologies?
- How does the geology of the oil or gas reservoir impact project design?
- What safety concerns and potential environmental impacts exist in offshore operations when employing these technologies?
Chapters 2 through 6 summarize the presentations and moderated discussion for a set of three keynote presentations (Chapter 2) and four different panels (Chapters 3 through 6). The keynote presentations included Evan Zimmerman, Offshore Operators Committee; David Payne, Chevron Corporation; and William Y. Brown, Bureau of Ocean Energy Management who provided the underlying background regarding well completion and stimulation technologies used in the offshore. The speakers discussed general practices from exploration to production for offshore oil and gas development and unconventional resources, an overview of offshore well completion and stimulation technologies, and offshore regulatory and environmental considerations.
Substantial differences exist between oil and gas development in the onshore and offshore environments—for example, the equipment deployment logistics in offshore environments for drilling and production, and particularly at increasing water depths, require different approaches and strategies to facilitate oil and gas extraction and manage risk compared to onshore environments. The logistical differences between onshore and offshore drilling are also linked to differences in the geology of the intended drilling target. The geological history of the target rock formation influences, for example, its permeability and porosity, which in turn influence techniques and goals for well stimulation and completion. A summary of the panel presentation introducing readers to the life cycle of offshore oil and gas development from Azra N. Tutuncu, Colorado School of Mines, appears in Chapter 3, and summaries of presentations about technology deployment and practice in the offshore from Dennis McDaniel, Anadarko Petroleum Corporation, and Lisa Grant, Bureau of Safety and Environmental Enforcement, are provided in Chapter 4.
These decisions about stimulation techniques and goals also impact production costs, monitoring strategies, safety approaches, and policy decisions. The offshore industry has had a
strong safety record related to deepwater production operations on the U.S. Outer Continental Shelf (OCS), according to Bud Danenberger, Independent Consultant. In terms of offshore safety, members of industry and regulating bodies alike play important roles in maintaining an operating culture that is safe for workers and the natural environment. Summaries of panel presentations from Benjamin Coco, American Petroleum Institute (Chapter 3), and from Danenberger; Paul Hebert, Chevron Corporation; and Nancy Tippins, CEB (Chapter 5) reveal more detailed information about regulatory initiatives, industry standards, and operational practices for increased safety in the offshore oil and gas industry.
In addition to the differences that exist between the onshore and offshore environments, differences are also evident when comparing one offshore region to another. Michael Schexnailder, Halliburton, and Mike Hecker, ExxonMobil provided overviews, respectively, of the operational differences between offshore development in the Gulf of Mexico and offshore California (Chapter 4). The different characteristics of these locations call for varied regulations and safety standards appropriate for each environment that, in turn, demand a high level of collaboration and coordination among multiple entities (e.g., service providers, operators and regulators). For example, states regulate operations in state waters, while federal agencies regulate operations in the OCS in conjunction with the appropriate states. Bradley Watson, Coastal States Organization, highlighted some of these state responsibilities and federal partnerships (Chapter 3).
Because the operating environments of the oil and gas industry are so diverse, it can be difficult to transfer this knowledge effectively among a broad audience that includes government decision makers, academic researchers, industry representatives, and members of the public. Accurate information is essential to support science- and technology-based decisions and to manage risk related to environmental and human health and safety. The data generated from decades of research on the environmental impacts of offshore oil and gas operations can be used to inform lease and permit approval decisions, to prevent or mitigate negative impacts to the environment, to increase system resilience, to inspire collaborative opportunities, and to educate affected communities. Environmental concerns, related research, relevant regulations, and useful technologies were addressed by the fourth and final panel in the workshop (Chapter 6): James Ray, Oceanic Environmental Solutions, LLC; Paul Montagna, Texas A&M University–Corpus Christi; Robert Habel, California Department of Conservation; and Desikan Sundararajan, Statoil.
To commence the workshop, Roundtable co-chairs David Dzombak, Carnegie Mellon University, and Wendy Harrison, Colorado School of Mines, offered an overview of the Roundtable’s work. Since its formation in 2015, the Roundtable has held two prior workshops: they first discussed the reuse of flowback and produced waters,2 and the second considered two separate topics, environmental legacy issues and induced seismicity, linked through the common theme of risk management.3 Both of these workshops focused on unconventional hydrocarbon development in the onshore environments. Workshop co-chair Melissa Batum, Bureau of Ocean Energy Management, expressed the planning committee’s hope that this third Roundtable workshop would begin to bring awareness of and clarity to the application of unconventional resource development technologies in offshore environments. She explained that the workshop would offer an introduction to the various stages of offshore oil and gas
operations and an overview of specific technologies for well completion, as well as a discussion of safety and environmental concerns associated with those technologies. Workshop co-chair Joe Lima, Schlumberger, indicated that the workshop would explore this information via comparisons between the offshore environments in the Gulf of Mexico and California.
This Proceedings of a Workshop was prepared by a rapporteur as a factual summary of what occurred at the workshop. The planning committee’s role was limited to planning and convening the workshop. The views contained in this proceedings are those of the individual workshop participants and do not necessarily represent the views of all workshop participants, the planning committee, or the National Academies of Sciences, Engineering, and Medicine.
After the summaries of each presentation and accompanying moderated discussions are provided in the chapters that follow, supporting material is provided in the references and appendixes. Appendix A presents the workshop agenda; Appendix B contains a list of the Roundtable members; Appendix C provides biographies of the planning committee members; Appendix D offers biographical information of workshop moderators and presenters; Appendix E is a list of workshop participants; and Appendix F contains a glossary of frequently used terms. In addition to the summary provided here, materials related to the workshop, including videos, presentations, and discussion sessions can be found at http://nas-sites.org/uhroundtable/meetings.