SPE Denver General Meeting: September 2026
Title: “From Heel to Toe: Engineering Uniform EGS Injection”
Abstract:
EGS circulates cooler water through hydraulically connected horizontal wells, creating a subsurface heat exchanger. Ideally, the injection is evenly distributed across the fracture network to promote uniform thermal drawdown; however, fracture variability and wellbore friction can concentrate flow in high-conductivity pathways or heel-biased stages, reducing sweep efficiency and accelerating thermal breakthrough. Modeling indicates conformance control providing uniform injection can increase 30-year power generation by 50%. This presentation summarizes surface qualification testing by GTO Technologies of a second-generation casing sleeve, pump-down actuation system, and high-temperature tractor designed to deliver uniform EGS injection independent of fracture conductivity. The system preserves full inner diameter from heel to toe and avoids telescoping ball seats while providing regulated flow through an outflow control device. The larger casing inner diameter also reduces parasitic pumping losses from wellbore friction and supports higher injection rates at lower pressures.
Speaker Bio:
Dr. Will Fleckenstein is a registered engineer and co-founder of GTO Technologies; a start-up funded with a $5 million seed round focused on commercializing EGS conformance-control technologies. He served as the PI for a $5.3 million DOE grant through the Utah FORGE project to develop the world’s hottest-temperature tractor and first-generation stimulation and conformance-control tools. Dr. Fleckenstein retired from the Colorado School of Mines on June 30, 2026, after 26 years as a non-tenure-track faculty member, including service as the Petroleum Engineering Department Head from 2012 to 2014. Dr. Fleckenstein has 40 years of industry experience, including a first job as a roughneck on rigs working in the Salton Sea geothermal field and has drilled, completed or worked over at least 200 wells in his career. Since 2009, he has also served as Board Chair of the Credit Union of Colorado, with170,000 members and $2.6 billion in assets.
Sponsored by: Drift Consulting Solutions