Chevron CRUSH is an experimental ''

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

shale oil extraction Shale oil extraction is an industrial process for unconventional oil production. This process converts kerogen in oil shale into shale oil by pyrolysis, hydrogenation, or thermal dissolution. The resultant shale oil is used as fuel oil or up ...

technology to convert

kerogen Kerogen is solid, insoluble organic matter in sedimentary rocks. Comprising an estimated 1016 tons of carbon, it is the most abundant source of organic compounds on earth, exceeding the total organic content of living matter 10,000-fold. It ...

oil shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...

shale oil Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock (kerogen) into synthetic oil and gas. The resulting oil c ...

. The name stands for Chevron's Technology for the Recovery and Upgrading of Oil from Shale. It is developed jointly by Chevron Corporation and the

Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, ...

History

The Chevron CRUSH technology bases on the earlier ''in situ'' efforts. Sinclair Oil Corporation conducted an experiment using both natural and induced fractures to establish communication between wells and developing an ''in situ'' combustion process. Geokinetics, the

Sandia National Laboratories Sandia National Laboratories (SNL), also known as Sandia, is one of three research and development laboratories of the United States Department of Energy's National Nuclear Security Administration (NNSA). Headquartered in Kirtland Air Force Bas ...

, and the Laramie Energy Technology Center of the U.S. Department of Energy conducted field tests fracturing oil-shale formation by explosives and hydraulic fracturing technology. Equity Oil Company,

Continental Oil Company Conoco Inc. ( ) was an American oil and gas company that operated from 1875 until 2002, when it merged with Phillips Petroleum to form ConocoPhillips. Founded by Isaac Elder Blake in 1875 as the "Continental Oil and Transportation Company". Curre ...

and the

University of Akron The University of Akron is a public research university in Akron, Ohio. It is part of the University System of Ohio. As a STEM-focused institution, it focuses on industries such as polymers, advanced materials, and engineering. It is classifie ...

studied the benefit of carbon dioxide as a carrier gas to facilitate a higher yield of shale oil. Based on these works, Chevron Corporation and the Los Alamos National Laboratory started a cooperation in 2006 to improve the recovery of hydrocarbons from oil shale. In 2006, the United States Department of the Interior issued a research, development and demonstration lease for Chevron's demonstration project on public lands in Colorado’s

Piceance Basin The Piceance Basin is a geologic structural basin in northwestern Colorado, in the United States. It includes geologic formations from Cambrian to Holocene in age, but the thickest section is made up of rocks from the Cretaceous Period. The basi ...

. In February 2012, Chevron notified the Bureau of Land Management and the Department of Reclamation, Mining and Safety that it intends to divest this lease.

Process

For decomposition kerogen in oil shale, the Chevron CRUSH process uses heated

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

. The process involves drilling vertical wells into the oil shale formation and applying horizontal fractures induced by injecting carbon dioxide through drilled wells and then pressured through the formation for circulation through the fractured intervals to rubblize the production zone. For further rubblization propellants and explosives may be used. The used carbon dioxide then be routed to the gas generator to be reheated and recycled. The remaining organic matter in previously heated and depleted zones is combusted ''in-situ'' to generate the heated gases required to process successive intervals. These gases would then be pressured from the depleted zone into the newly fractured portion of the formation and the process would be repeated. The hydrocarbon fluids are brought up in conventional vertical oil wells.

Isolation of groundwater

The processing area is isolated from surrounding groundwater by creating fractured areas ("pockets"), approximately wide and high within the center of the oil shale deposit. In this way, about of the confining layer would separate the process area from the water bearing layers above and below, keeping the aquifers out of the production zone.

References

{{Reflist, 2 Oil shale technology Chevron Corporation Hydraulic fracturing Oil shale in the United States

History

Process

Isolation of groundwater

See also

References