Modern Perspective on Gas Hydrates
After lying hidden in sediments for thousands of years, delicate frozen gas structures are in the spotlight for both scientific research and the national interest. These structures, known as gas hydrates, are being investigated by scientists the world over for their possible contributions to the global energy mix, as well as their potential interaction with the environment.
The number of discoveries and advances regarding gas hydrates has advanced at a rapid pace in recent years. As a leading voice in international gas-hydrate research, the USGS has contributed substantially to the discourse. Now, to take stock of where we are and what is known about gas hydrates, the USGS has published two new fact sheets focused on methane hydrates.
The first fact sheet (see “Gas Hydrate in Nature”) provides up-to-date information about naturally occurring gas hydrates, including their global distribution, the amount of gas trapped in these deposits, and the technology used to find them. The second fact sheet (see “The U.S. Geological Survey’s Gas Hydrates Project”) describes the USGS Gas Hydrates Project, which collaborates with other U.S. federal agencies, international partners, and academic researchers to enhance understanding of the resource potential of gas hydrates (see “Exploring Gas Hydrates as a Future Energy Source”) and the interaction of gas hydrates with the changing environment (see “Gas Hydrate Breakdown Unlikely to Cause Massive Greenhouse Gas Release”).
A Key Research Field Crystallizes
Gas hydrate forms naturally when water combines with certain gases at low temperatures and moderate pressures to produce a frozen solid (see “Gas Hydrates Primer”). Methane, which is often referred to as “natural gas,” is the gas most often trapped in gas hydrate. Globally, most methane hydrate is found below the seafloor at water depths greater than 300-500 meters (984–1,640 feet) on the margins of continents. Gas hydrate also forms in and beneath permanently frozen ground (permafrost) at high northern latitudes and in the ground beneath large ice sheets (e.g., those on Greenland and Antarctica) and some glaciers.
The “Gas Hydrate in Nature” fact sheet compiles critical background information about methane hydrate. For example, gas hydrate traps about one-sixth of the methane moving through the global terrestrial-ocean-atmosphere system. Because gas hydrate is a concentrated form of methane and is found in deposits that are shallower than conventional gas reservoirs, some countries are investigating the possibility of extracting methane from these deposits to meet resource needs. The fact sheet also provides a timeline for major U.S. and international research activities that have investigated natural gas hydrates since 1990.
A Legacy of Scientific Achievements
The “USGS Gas Hydrates Project” fact sheet describes the research carried out by USGS scientists who support the resource, environmental, and geohazards goals of the project, which is jointly supported by the Coastal and Marine Geology Program (CMGP) and the Energy Resources Program (ERP).
John Haines, Program Coordinator for CMGP and Acting Associate Director for the USGS Natural Hazards Mission Area, commented that, “These new fact sheets highlight the role that the USGS Gas Hydrates Project plays in advancing national and international understanding of natural methane hydrates in collaboration with critical partners like the U.S. Department of Energy. Our stakeholders will benefit from access to the clear, up-to-date information provided on these fact sheets.”
Start with Science
The USGS has been active in methane hydrates research for more than three decades. Among the seminal contributions of the USGS Gas Hydrates Project have been participating in and sometimes managing large-scale drilling projects that investigate the resource potential of gas hydrates in Alaska (see “Successful Test of Gas Hydrate Production Test Well Ignik Sikumi on Alaska's North Slope”), offshore India (see “Results of the India National Gas Hydrate Program Expedition 02”), and the Gulf of Mexico (see “Gulf of Mexico Gas Hydrate Joint Industry Project”); providing unique electron-microscopy imaging capabilities and special high-pressure laboratory facilities to study hydrates in conditions close to their natural state; producing the first assessment of technically-recoverable gas-hydrate resources; characterizing the physical properties of hydrate-bearing sediments to constrain reservoir properties; unraveling the possible synergies between gas-hydrate breakdown and environmental change; and acquiring data to image the distribution of these deposits on the U.S. Atlantic (see “Imaging Methane Seeps and Plumes on the U.S. Atlantic Margin”), Gulf of Mexico (see “Seismic-Imaging Research Cruise Investigates Deepwater Gas Hydrate Deposits in the Gulf of Mexico”), and Beaufort Sea margins.
Carolyn Ruppel, Chief of the USGS Gas Hydrates Project and author of the new fact sheets, said, “USGS scientists frequently receive requests for information about natural gas hydrates and international priorities for gas-hydrate studies. At the same time, federal agency partners, academic collaborators, international collaborators, and the public sometimes need a succinct description of the USGS Gas Hydrates Project and its activities. These fact sheets should provide a consistent message to respond to such needs for many years to come.”
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