Review of Drilling Performance in a Horizontal EGS Development

Abstract

Drilling costs constitute a major part of geothermal development capital costs. Many conventional geothermal developments lack geologic consistency and the scale and continuous scope of operations needed to leverage the duration and cost advantages that a drilling learning curve may yield. A significant advantage of proposed EGS projects is the repeatability of projects in similar geologic conditions in a condensed area. This allows for geologic, technical, and operational learnings to be applied directly from project to project. This paper presents drilling data from Fervo Energy’s first eight horizontal EGS wells during which significant performance improvements have been achieved. The paper will describe the processes and methodologies applied to deliver a geothermal drilling learning curve and provide an outlook on its implications for the potential and economics of future EGS projects.