1. Field of the Invention
This invention relates to a method of power generation, and, in particular, to a method of geothermal power generation.
2. Brief Statement of the Prior Art
The successful geothermal power projects to date have exploited subterranean steam reservoirs. The more common subterranean brine reservoirs have not been developed, primarily because of the difficulties experienced in producing hot geothermal brine. The brine is difficult to produce because it forms scale deposits, chiefly calcium carbonate, when it is depressured. Attempts to avoid the scaling have included the use of down hole heat exchangers, however, the corrosive nature of the brine makes this approach impractical.
In my prior patent, U.S. Pat. No. 4,059,156, I disclose and claim a method for producing brine by injecting, into a column of brine, a low density lift medium which is sufficient to reduce the density of the resulting mixture, permitting it to be produced by the hydrostatic head of the brine column without any significant depressuring of the brine. Thereafter, the brine can be depressured above surface in equipment adapted for handling of slurries and scaling liquids.
While the method described and claimed in my aforesaid patent is a substantial improvement in geothermal brine production, improvements are desirable in increasing the thermal efficiency of the process by providing increased recovery of energy from the produced brine.