Patent ID: 9051827
Filing Date: 2015-06-09
Classification: E21B

Abstract:
1. A method for preventing silica scale in geothermal brine reinjection wells by selectively removing silica from a geothermal brine solution, the method comprising the steps of: obtaining a geothermal brine solution comprising silica; maintaining the pH of the geothermal brine solution at a pH of between 4 and 6.25; contacting the geothermal brine solution comprising silica with activated alumina, such that silica present in the geothermal brine solution selectively binds to the activated alumina; recovering an aqueous brine product stream from the contacting step, said aqueous product stream having a reduced silica concentration relative to the geothermal brine solution; and injecting the aqueous brine product stream into the geothermal well, the aqueous brine product stream comprising less than about 80 ppm of silica.