| Title | DGS High-Capacity, Single Well, Full Hydraulic Circuit Technology Refinements for EGS |
|---|---|
| Authors | William K OTT and Jeffery A SPRAY |
| Year | 2023 |
| Conference | Stanford Geothermal Workshop |
| Keywords | EGS, DGS, HDR, conductive reservoir, diverting barrier, isolating packers, fluid sweep |
| Abstract | An innovative method that extracts global scale energy from HDR while eliminating geothermal’s fundamental problems obsolesces current EGS approaches. Called “DGS,†the single vertical well format features complete control over reservoir hydraulics and heat recovery and can produce 50 MW from top 1/5th thermal gradient rock anywhere in the world. Based on downhole materials and procedures known to the developers for decades, DGS works by installing flow diverters in engineered reservoirs that cause heat-carrying fluid to travel across 60+M sq. ft. (630 hectares) of subsurface rockfaces. The diverters are installed in a manner effecting hydraulic channel definition in the reservoir, where sweep efficiency is controllable, enabling more than 90% heat recovery. Set in deeper, hotter strata, generally 2X that of traditional EGS, high rock closure pressure mitigates natural fracture presence and connectivity, all but eliminating ever-present water loss problems and seismicity potential. DGS Technology developers also present in their paper the system’s high-temperature proppant carrying fluid, certain means of reservoir diverter construction, novel multi-set thermally compliant packer assemblies, and methods of heat transfer optimization. |