US Patent 11685604 Underground energy storage systems

Systems for underground energy storage and methods for their construction. Methods include forming a plurality of chambers underground connected to a plurality of multiple flow conduits, the plurality of chambers including an upper chamber and a lower chamber each containing a working fluid, each multiple flow conduit of the plurality of multiple flow conduits comprising an inner tubular segment having a flowbore interior to the inner tubular segment configured to flow the working fluid, and an outer tubular segment containing the inner tubular segment, wherein each multiple flow conduit defines an annulus between the outer tubular segment and the inner tubular segment configured to flow a compressed gas, by drilling a borehole in the earth formation, installing an outer tubular segment in the borehole, cementing the outer tubular segment at a target location, and installing the inner tubular segment inside the outer tubular segment.