A system is disclosed for generating energy from a geothermal heat source. The system includes a fluid injection system configured for injecting fluid into a subterranean formation and a fluid extraction system configured for extracting fluid from the subterranean formation after being heated by the formation. The system further includes a heat transformer configured to receive a first fluid heated by the geothermal heat source at a first temperature and adapted to heat a second fluid to a second temperature via a series of chemical reactions. Furthermore, the system includes an energy generation unit configured to receive heated the second fluid at the second temperature from the heat transformer to increase the temperature of a third fluid which is used to generate energy.
Wellheads for coupling to a heater located in a wellbore in a subsurface formation are described herein. At least one wellhead may include a heater located in a wellbore in a subsurface formation; and a wellhead coupled to the heater. The wellhead may be configured to electrically couple the heater to one or more surface electrical components. The wellhead may include at least one non-ferromagnetic material such that ferromagnetic effects are inhibited in the wellhead. Systems and methods for using such wellheads for treating a subsurface formation are described herein.
A method for treating an oil shale formation comprising nahcolite includes providing a first fluid to a portion of the formation. A second fluid is produced from the portion. The second fluid includes at least some nahcolite dissolved in the first fluid. A controlled amount of oxidant is provided to the portion of the formation. Hydrocarbon fluids are produced from the formation.
A method of forming and maintaining a low temperature zone around at least a portion of a subsurface treatment area is described. The method includes reducing a temperature of heat transfer fluid with a refrigeration system. The heat transfer fluid is circulated through freeze well canisters and placed in a formation around at least a portion of the subsurface treatment area. An initial temperature of the heat transfer fluid supplied to a first freeze well canister is in a range from about -35 .degree. C. to about -55 .degree. C. At least one of the well canisters includes carbon steel. The heat transfer fluid is returned to the refrigeration system.
Method for treating a hydrocarbon containing formation are described herein. Methods may include providing heat to two or more first sections of the formation with one or more first heaters in two or more of the first sections. The provided heat may mobilize first hydrocarbons in two or more of the first sections. At least some of the mobilized first hydrocarbons are produced through production wells located in two or more second sections of the formation. The first sections and the second sections are arranged in a checkerboard pattern. A portion of at least one of the second sections proximate at least one production well is provided some heat from the mobilized first hydrocarbons, but is not conductively heated by heat from the first heaters. Heat may be provided to the second sections with one or more second heaters in the second sections to further heat the second sections.
A method includes producing formation fluid from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a gas stream. At least a portion of the liquid stream is provided to a hydrotreating unit. At least a portion of selected in situ heat treatment clogging compositions in the liquid stream are removed to produce a hydrotreated liquid stream by hydrotreating at least a portion of the liquid stream at conditions sufficient to remove the selected in situ heat treatment clogging compositions.
