The primary objective achieved in this project was to identify sites for test wells capable of long-term production of methane-bearing water from the shallow geopressured and deep hydropressured zones. The process of test-well site selection involved several steps, each contributing to the basic knowledge of shallow geopressured and deep hydropressured aquifers.
First, zones within the geopressured and deep hydropressured section of the Texas Gulf Coast Tertiary were defined based on pressure gradients and temperatures. Next, high-sandstone corridors, corresponding to the trends of the Wilcox Group and Frio Formation, were identified for each of these zones. Five fairways, or areas of greatest net-sandstone thickness, were located within the corridors. Areas most prospective for testing entrained methane resources in the shallow geopressured and deep hydropressured zones were identified in each fairway. Finally, test sites were selected in four of the prospect areas: the Blessing Prospect in Matagorda County, the Nueces Bay and Corpus Channel Prospects in San Patricio and Nueces Counties, and the Sarita Prospect in Kleberg County.
Knowledge gained from these geologic studies and subsequent testing will be significant in (1) evaluating the technical and economic feasibility of producing solution gas from the shallow geopressured and deep hydropressured zones, and (2) comparing these zones with deeper, hotter geopressured zones (studied previously in DOE-funded projects) as sources of entrained methane.Bureau of Economic Geolog
