Depositional and Structural Challenges of the Wilcox Lobo Natural Gas Trend, South Texas

To increase understanding and utilization of gas resources in the Wilcox Lobo play of South Texas, this report reviews current geological knowledge of the Lobo trend. An additional objective of this report is to identify areas where advancements in geological understanding could lead to substantial improvements in efficient development of the Wilcox Lobo trend natural gas resource. According to published accounts, Lobo sandstones formed in a variety of depositional environments in both shallow and deep marine waters. During and after deposition, the Lobo experienced repeated episodes of erosion, faulting, and diagenesis. Thus, accurate prediction of reservoir sandstone attributes is difficult, and this difficulty is cited by operators as a significant challenge to efficiently targeting the remaining gas resource. Knowledge that would aid in the emergence of this resource includes information on sandstone correlation and accurate zone identification, depositional systems and facies interpretations, controls on fault pattern variability, and, to a lesser extent, recognition of diagenetic patterns and faults and fractures that are below seismic resolution. Geologic challenges of the Lobo trend are opportunities for targeting increasingly smaller and more difficult-to-detect compartments with advanced technology.