Occidental Petroleum

Frederic B Boucher

Edward F Wahl, Iii

Process for recovery of energy from geothermal fluids such as geothermal brine in a geothermal formation by injecting a water immiscible working fluid, preferably organic, typically a hydrocarbon, e.g. isobutane, into the geothermal formation containing a geothermal fluid such as hot brine, wherein the hydrocarbon working fluid is heated by direct heat exchange contact with the hot geothermal fluid in the formation, and employing the hot working fluid to drive a heat engine or turbine to produce work or electrical energy or to provide heat energy to a chemical process (e.g., alcohol manufacture). The cooled working fluid discharged from the turbine is reinjected into the geothermal formation. The working fluid preferably has a density which changes substantially with temperature to provide a substantial pressure difference for causing flow of heated working fluid up the production well. The density difference can be due to phase transfer from liquid to gas.

Geothermal energy production

Process and system for recovery of energy from geothermal brines and other hot water sources, by direct contact heat exchange between the brine or hot water, and an immiscible working fluid, e.g. a hydrocarbon such as isobutane, in a heat exchange column, the brine or hot water therein flowing countercurrent to the flow of the working fluid. The column can be operated at subcritical, critical or above the critical pressure of the working fluid. Preferably, the column is provided with a plurality of sieve plates, and the heat exchange process and column, e.g. with respect to the design of such plates, number of plates employed, spacing between plates, area thereof, column diameter, and the like, are designed to achieve maximum throughput of brine or hot water and reduction in temperature differential at the respective stages or plates between the brine or hot water and the working fluid, and so minimize lost work and maximize efficiency, and minimize scale deposition from hot water containing fluid including salts, such as brine. Maximum throughput approximates minimum cost of electricity which can be produced by conversion of the recovered thermal energy to electrical energy.

Recovery of energy from geothermal brine and other hot water sources

Recovery of energy from geothermal brines and other hot water sources by direct contact heat exchange with a working fluid, such as a hydrocarbon working fluid, e.g. isobutane. The process and system consists of a plurality of stages, each stage including mixing and settling units. In the first stage, hot brine and arm working fluid are intimately mixed and passed into a settler wherein the brine settles to the bottom of the settler and the hot working fluid rises to the top. The hot working fluid is passed to a heat engine or turbine to produce work and the working fluid is then recycled back into the system. The system is comprised of a series of stages each containing a settler and mixer, and wherein the working fluid and the brine flow in a countercurrent manner through the stages to recover the heat from the brine in increments and raise the temperature of the working fluid in increments.

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San Juan Capistrano, CA, United States of America

Frederic B Boucher