A New Assessment of the Extractable Geothermal Energy from Deep Sedimentary Formations in Texas
Bruce Cutright, Kevin Meyer, and Daniel Zafar
Previous assessments of geothermal energy from deep sedimentary formations in Texas conducted during the 1970s and 1980s provided useful and promising information on the magnitude of the resource but focused predominantly on the resource-in-place. More recent evaluations within the last two years approached the problem in a different way, using a reservoir characterization modeling approach, and, again, provided a very useful description of an undeveloped resource with great potential. A new and more detailed database of bottom hole temperature measurements became available in 2012. Information from this expanded database is now available for the State of Texas and has allowed a new, refined assessment to be completed. We present herein a review of the previous studies of the geothermal energy potentially from deep sedimentary formations in Texas and the Texas Gulf Coast and compare earlier results with our new assessment derived using over 50,000 bottomhole temperature measurements from throughout Texas. The new assessment indicates that the magnitude of extractable energy in Texas, assuming existing technology, exceeds two trillion barrels of oil equivalent. This resource magnitude assessment is based on a rather conservative approach, but inclusion of minor improvements in drilling technology, thermal to electrical energy conversion, alternative heat mining fluids or the application of formation stimulation techniques such as hydrofracturing result in a significant expansion of this estimate. Economic calculations are also derived indicating that geothermal energy from these deep sediments can produce electrical power using existing technology at rates that are competitive with fossil fuel sources without subsidies.
AAPG Search and Discovery Article #90167©2013 GCAGS and GCSSEPM 63rd Annual Convention, New Orleans, Louisiana, October 6-8, 2013