Shale Oil Extraction - In Situ Technologies

In Situ Technologies

In situ technologies heat oil shale underground by injecting hot fluids into the rock formation, or by using linear or planar heating sources followed by thermal conduction and convection to distribute heat through the target area. Shale oil is then recovered through vertical wells drilled into the formation. These technologies are potentially able to extract more shale oil from a given area of land than conventional ex situ processing technologies, as the wells can reach greater depths than surface mines. They present an opportunity to recover shale oil from low-grade deposits that traditional mining techniques could not extract.

During World War II a modified in situ extraction process was implemented without significant success in Germany. One of the earliest successful in situ processes was underground gasification by electrical energy (Ljungström method)—a process exploited between 1940 and 1966 for shale oil extraction at Kvarntorp in Sweden. Prior to the 1980s, many variations of the in situ process were explored in the United States. The first modified in situ oil shale experiment in the United States was conducted by Occidental Petroleum in 1972 at Logan Wash, Colorado. Newer technologies are being explored that use a variety of heat sources and heat delivery systems.