Development of Second Generation Sleeve Based Conformance Control System for EGS

Abstract

Enhanced Geothermal Systems (EGS) using induced and natural fractures require uniform fluid flow distribution for the most economic power production. An extended circulation test of August 2024 at the Utah FORGE Site between two extended reach wells completed with “Plug and Perf” methods yielded non-uniform flow between the wells in the induced fractures from the first three fracture zones. To overcome the differences in fracture conductivity between wells and wellbore friction that is the root of the non-uniform flow, a low-cost and rapid multistage fracture stimulation technology with cemented casing frac sleeves that also have the ability to regulate flow through the sleeve is being developed and tested with a high temperature tractor to detect and control flow of heat-carrier fluid. This paper reports on the progress of the development of a second-generation sleeve, actuation system, and high temperature tractor, with the goal to provide a uniform injection profile, regardless of the conductivity of fractures between injection and producing wells. Modeling has shown that conformance control may provide a 50% uplift in power generation over a 30-year life as compared to wells without conformance control, for similar costs and with less stress shadowing and a lower seismicity risk.