Economic appraisal and scoping of geothermal energy extraction projects using depleted hydrocarbon wells

Abstract

This study offers a first step in examining a potential solution for what to do with the ever-increasing number of horizontal shale wells in the United States (and lately, Argentina and China), as they come to the end of their economic life. A comprehensive decision-making tool was developed for scoping assessments based on the technical and economic appraisal of abandoned hydrocarbon wells repurposed into enhanced geothermal systems. We specifically target near end-of-life oil and gas wells, re-commissioned to extract geothermal energy as opposed to hydrocarbons, because these potential geothermal resources are prevalent near a handful of major US population and energy demand centers, including Pittsburgh, Houston, Denver, Dallas, Oklahoma City and San Antonio. This study addresses some of the technical challenges associated with such projects. However, the main focus is on (1) the probabilistic evaluation of the economic net present value, and (2) specific solutions for possible commercial deal structures required for negotiation and project implementation. The backdrop for the test case in this study is the new Texas A&M RELLIS Campus being constructed in College Station, Texas. A successful commercial model for the use of abandoned oil and gas wells to extract low and medium temperature geothermal resources could spur further development and a pilot study is proposed for this green source of energy. Our estimations suggest a net present value of $1.2 billion could be unlocked in the US alone, through the repurposing of wells, previously used for hydrocarbon extraction only.