Wellhead brine treatment

Abstract

This invention relates to methods, systems and apparatus for producing primary treated brine, i.e. <20 ppm calcium, magnesium, strontium and barium ions at the wellhead of underground salt caverns formed by depletion of their salt content by previous solution mining operations. The purified brine produced is maintained in an anerobic state and transported to chlor-alkali plant installations for use in electrolysis cells for the production of chlorine, sodium hydroxide and hydrogen. Raw brine produced at an operating brine wellhead is injected into a depleted salt cavern along with the treatment chemicals required to purify the raw brine. A novel installation including a producing well or wells, a depleted well cavern or caverns, and support facilities for producing primary treated brine is provided. Also, special wellhead injection tubing, a mixer and radial distributor for injecting the fluids into the cavern are employed which allows for the chemical reaction, precipitation, settling and clarification operations to take place in a pre-selected reaction zone in the cavern. The cavern acts as the reactor for precipitation, settler and clarifier and deposition site for storage of the precipitates which are innocuous solid by-products of the purification process. The methods, systems, installations and apparatus of this invention provide environmental, investment cost and operating advantages, as compared to surface brine treating facilities and operations at the chlor alkali plant installation, or, as compared to other subterranean attempts to purify brine.

Dependencies are inferred from the claim text.