WorldWide Drilling Resource

35 WorldWide Drilling Resource ® AUGUST 2018 Gas Hydrates as a Source of Natural Gas? Adapted from Information by the U.S. Geological Survey After lying hidden in sediments for thousands of years, frozen gas structures, known as gas hydrates, are being investigated by scientists all over the world for their possible contributions to global energy, as well as their potential interaction with the environment. Gas hydrate forms when water combines with certain gases at low temperatures and moderate pressures to produce a frozen solid. The type of gas most often trapped in gas hydrate is methane. This means it represents a concentrated, shal- lowly buried form of natural gas, which could be used as an energy resource. Most methane hydrate is found below the seafloor on the margins of continents. It also forms in and beneath permanently frozen ground (permafrost) at high northern latitudes, as well as in the ground beneath large ice sheets and some glaciers. The U.S. Geological Survey (USGS) has conducted methane hydrate research for more than three decades. The Gas Hydrates Project is a collaboration between the USGS Energy Resources and the USGS Coastal and Marine Geology Programs. It works closely with other U.S. Federal agencies, some State governments, outside research or- ganizations, and international partners. The project studies the formation and distribution of gas hydrates in nature, the potential of hydrates as an energy resource, and the inter- action between methane hydrates and the environment. USGS scientists acquire new geophysical data, as well as samples of sediments, the water column, and the atmosphere. In addition, project personnel analyze datasets provided by partners and manage unique laboratories which supply innovative analytical capabilities. A petroleum systems framework is used to evaluate sedimentary basins which may contain high-concentration gas hydrate deposits. They often analyze existing seismic and borehole logging data to determine where gas hydrate is concentrated. In 2008, the USGS completed the first ever assessment of recoverable methane from gas hydrates by using existing technology. It focused on permafrost-associated gas hydrates on the Alaskan North Slope and adopted methodology which can be extended to other gas hydrates. Project scientists have led, advised, or participated in more than a dozen domestic and international drilling projects. These research wells can improve information about the potential viability of gas hydrates as an economic source of natural gas. A sample of gas hydrate. A test well for collecting gas hydrates in Mallik, Canada. G&O