Geothermal brine production

Abstract

There is disclosed a method for the production of geothermal brines that avoids depressuring the brine below its flash point in the well bore and thereby avoids the scaling and plugging unavoidably experienced whenever high salt content brines are depressured, releasing carbon dioxide and upsetting their solubility equilibrium and precipitating calcium carbonate. The invention avoids the flashing of the geothermal brine by injecting a lift fluid immiscible with and of substantially lesser density than the brine into the production tubing to form a column of a mixture of brine and lift fluid which has a sufficiently lesser density than the column of brine that the hydrostatic head of the column of brine raises the mixture to the surface from where it is withdrawn without flashing, separating the lift fluid and processing the brine for heat recovery. Where the brine is extremely hot, the pressure is maintained at higher levels to avoid flashing by an additional column of brine below the production level. This is provided by establishing a column of the geothermal brine a substantial depth below its production interval, installing a production tubing for a substantial depth in the column of brine and injecting a lift fluid which yields a higher pressure at the top of the well.

Dependencies are inferred from the claim text.