Modern Perspective on Gas Hydrates

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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 hydrate, 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 U.S. Geological Survey has contributed substantially to the discourse. Now, to take stock of where we are and what is known about gas hydrates, USGS has published two new fact sheets focused on methane hydrates.

Image shows burning gas hydrates
Natural gas from gas hydrates burning. Methane, the primary component of natural gas, is the most common of the gases that form gas hydrate. In fact, the amount of natural gas within the world’s gas hydrate accumulations is estimated to greatly exceed the volume of all known conventional gas resources. Because of that potential, the USGS and academic, government, and private industry scientists and engineers have been studying how to produce natural gas from hydrates for many decades. Read more about our gas hydrate research here. Image courtesy of the Department of Energy.(Public domain.)

The first fact sheet 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 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 and the interaction of gas hydrates with the changing environment.  

A man pulls a chunk of frozen ice from a core collection tube, the ice is lumpy and interspersed with dark sediment
In 2010, the U.S. Geological Survey recovered white chunks of gas hydrate (methane ice) mixed with gray sediment a few feet below the sea floor in the Arctic Ocean at a water depth of approximately 8,000 feet.(Public domain.)

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.  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., Greenland, Antarctica) and some glaciers. 

Image shows a map of the world with locations of gas hydrates marked
Map showing locations where gas hydrate has been recovered, where gas hydrate is inferred to be present on the basis of seismic data, and where gas hydrate drilling expeditions have been completed in permafrost or deep marine environments, also leading to recovery of gas hydrate. (Public domain.)

The “Gas Hydrates 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 earth-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.  

Image shows a graphic with various gas hydrate expeditions on a timeline
Timeline showing past and future drilling and deep-sea coring and borehole logging expeditions as of late 2017. The goal of the permafrost and deepwater marine programs is to evaluate the potential of gas hydrate as a resource, whereas the goal of the academic ocean drilling programs is to focus on critical research questions related to natural gas hydrate deposits. DOE refers to the U.S. Department of Energy. The academic programs are the Ocean Drilling Program (ODP; 1983–2003), the Integrated ODP (IODP; 2003–2013), and the International Ocean Discovery Program (IODP), which started in 2013. The international marine drilling programs are the Ulleung Basin Gas Hydrates project (UBGH; Korea), the National Gas Hydrates Project (NGHP; India), and the Guangzhou Marine Geological Survey (GMGS; China). (Public domain.)

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).  

USGS scientists stand on the edge of a ship, preparing equipment to go into the ocean
USGS scientists collect sediment samples in a gas hydrates area during a cruise on the U.S. Atlantic margin in 2015. (Public domain.)

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.”

 Scanning electron microscope image of gas hydrate crystals in a sediment sample.
 Scanning electron microscope image of gas hydrate crystals in a sediment sample. The scale is 50 micrometers (µm) or approximately 0.002 inches. (Public domain.)

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, offshore India, and the Gulf of Mexico; 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, 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.”