about 1,500 feet (about 500 meters) (Figure 1.1; Box 1.1). Although the estimated total global volume of methane in methane hydrate is still debated, generally acknowledged estimates yield figures between 2 and 10 times greater than those of technically recoverable conventional natural gas resources (see Chapter 2). The existence of such a large and as-yet untapped methane hydrate resource has provided a strong global research incentive to determine how methane from methane hydrate might be produced as a technically safe, environmentally compatible, and economically competitive energy resource (e.g., Council of Canadian Academies, 2008).
Although methane is a cleaner-burning energy source than other fossil fuels, it is itself a significant greenhouse gas, about 25 times more potent per molecule than carbon dioxide on a 100-year basis (International Energy Administration, 2009). Thus, understanding the potential environmental impacts of methane hydrate degassing3 and the seafloor hazard (“geohazard”) potential resulting from methane hydrate dissociation, whether through natural processes or through oil and gas drilling and production, is also important as its potential for commercial production is considered and tested.
The Department of Energy (DOE), through congressional authorization in the Methane Hydrate Research and Development Act of 2000 (P.L. 106-193), and as reauthorized in the Energy Policy Act of 2005 (P.L. 109-58) (Appendix A), has led a national research effort to understand (1) the physical nature of methane hydrate occurrences in sedimentary rock layers in offshore and in permafrost areas, (2) methods to quantify and explore for methane hydrate accumulations in nature, (3) the stability and behavior of methane hydrate when disturbed by drilling and production, (4) the technological requirements to produce methane from methane hydrate, and (5) the potential environmental impacts of methane