 Heated fluid was used to improve oil production and was one of the first attempts in enhanced oil recovery.Solar energy has been used in enhanced oil recovery as a thermal energy source since 1957 when Atlantic Richfield used it a California experimental facility.In the 1970s, research on the use of injecting CO2, or Carbon dioxide flooding, into wells for enhanced oil recovery led to better modeling techniques and understandings, especially in the area of the flow a heat injection into production wells.