Integrated subsurface characterization of a low-temperature geothermal test site, Gulf Coast, Texas

The study presents results from an integrated geologic and geophysical analysis for an upcoming geothermal field test at the Ellington Field Joint Reserve Base on the south side of Houston, Texas. The study area is situated in the well- known ‘geopressured geothermal’ fairway. We conduct an integrated subsurface analysis to identify and map a suitable formation for geothermal heat production. Based on our analysis, the Wilcox Formation and its underlying formations have the potential for suitable geothermal heat production in the study area. We expect to reach 200 °C at ∼5.6 km (∼18,373 ft) depth, which will be in the lower part of the Wilcox Formation or below. Although the Wilcox is expected to be mud-rich in the current study area, we expect to find thin sandstone packages, which we can fracture. The Wilcox sandstones at this depth are expected to have <= 10% porosity with 0.1 md of permeability.