Geothermal Map of Colorado, Wyoming, Montana, and Nebraska

Abstract

Mapping of heat flow is important in developing an understanding of the controls on heat flow and for locating thermal anomalies that can become the focus of geothermal development. The 2004 Geothermal Map of North America (Blackwell and Richards, 2004) shows regional heat flow values contoured from published data. Though the data used are appropriate for representing regional-scale thermal anomalies, the data density is too low in many areas to give the resolution required to identify smaller scale anomalies. To address this point, this study worked to increase data density by utilizing bottom-hole temperature (BHT) measurements from oil and gas wells. This paper focuses on the in-depth study of heat flow for portions of Colorado, Wyoming, Montana, and Nebraska. Because the majority of the BHT data used are from oil and gas exploration efforts, this study served primarily to add data within sedimentary basins for these states. Combining 2,858 BHT derived heat flow values with existing heat flow measurements, a 5’ x 5’ surface heat flow contour map was generated. The highlight of the results point to the Raton Basin of southern Colorado as a potential target for EGS exploration, where temperatures of over 120°C are observed at 2 km.