Robert Loucks of the Texas Bureau of Economic Geology talks bout the Austin Chalk trend in Texas. The Austin Chalk Trend along the onshore Gulf of Mexico is an active exploration and production trend, yet little has been published on the detailed reservoir geology. The Carbonate Reservoir Characterization Research Laboratory (RCRL) at the Bureau of Economic Geology, The University of Texas at Austin has undertaken a comprehensive core-based regional investigation of the Austin Chalk for the past five years.
The study covers the trend from the Texas-Mexico border through Louisiana. For this study, we have described ~40 cores and several well-exposed outcrops and we have constructed a large interactive database of core and thin-section descriptions, mineralogy XRD data, total organic carbon (TOC) and rock pyrolysis data, porosity and permeability data, SEM analyses, XRF analyses, and unconfined compressive strength (UCS) analyses.
The Austin Chalk is a complex mixture of lithofacies with wide-ranging mineral compositions, lithofacies-related TOC values, and poor reservoir quality. The basic geology must be defined to explore and exploit this terrigenous-rich chalk trend and to understand reservoir quality, source rock variability, and rock strength or brittleness. Our regional study has developed this basic understanding and our large geologic characterization database provides the range of expected basic parameters and characteristics.