Determining Geothermal Resources in Three Texas Counties

Abstract

The Southern Methodist University Geothermal Laboratory updated their quantification of the geothermal resources within and beneath the Texas oil and gas fields in Crockett, Jackson, and Webb counties as part of the research for the University of Texas Geothermal Entrepreneurship Organization research project DE-EE0008791. Through additional well sites drilled since 2000, the number of bottom-hole temperatures increased from 532 to 5,410. The research improved the methodology to calculate formation temperatures from 3.5 to 10 kilometers (11,480 to 32,800 feet) by using thermal conductivity values more closely related to the county geological formations, incorporating radiogenic heat production of geological formations, and updating the depth to the basement rocks. The results show deep temperatures as hotter than previously calculated, with temperatures of 150 °C (300 °F) possible for Webb, Jackson, and Crockett Counties on average at depths of 3.3, 3.7, and 4.0 kilometers (10,800, 12,100, and 13,100 feet), respectively. A target temperature of 150 °C is considered the minimum for efficient power generation, although cooler temperatures can be useful in other low-temperature applications. Therefore, geothermal resources are a new way to diversify the local electric grid with a baseload renewable energy option. It has the potential of making a significant energy contribution in the future.