Mechanical Specific Energy Analysis of the Utah FORGE Drilling

Abstract

One of the key findings of the 2014 Petroleum Practices Technology Transfer Committee report led by National Renewable Energy Laboratory (NREL) was that the geothermal drilling process lacked proper data collection while drilling, data integration, and analysis of such data. The lack of this essential engineering, well planning, and construction tool seemingly adds a significant amount of time to the 12-day additional non-productive time (NPT) at average per well while drilling geothermal wells versus oil and gas wells out of the 42 wells studied of the comparable order of magnitude of construction complexity. Geothermal Resource Group (GRG) has recently been involved in the construction of wells for a unique domestic enhanced geothermal system (EGS) observation drilling project (FORGE Utah) and implemented a hydraulic surface torque data collection system on a mechanical rig to analyze the MSE (mechanical specific energy), on the test well. We plan full instrumentation on the subsequent EGS wells. This paper presents the collection, evaluation, and the post-mortem comparison of the MSE to the drilling history.