A look into the Val Verde Basin, Texas

Abstract

Editor's note: This paper won the Best Poster Paper Award from the 2001 Annual Meeting in San Antonio. The study area consists of 180 miles2 within the Val Verde Basin. A new interpretation is proposed and is based primarily on 3D seismic data. Emphasis is placed on the Lower Permian to Pennsylvanian Section in which hydrocarbons have been found from tight reservoirs. The general stratigraphy is summarized, the focus being on hydrocarbon source, reservoirs, and seal. Seismic lines, spread across the area, illustrate structure. The producing fields sit atop the Foreland Thrust, which was transported as a decollement zone on Mississippian shales. A series of backthrusts is invoked to accommodate the movement of competent rocks up the ramped Foreland Thrust, creating the main structures in the fields. The Foreland Thrust is thought to be the primary migration pathway while the back-thrusts appear to be secondary migration pathways. The new interpretation incorporates 3D seismic, well, and reservoir performance data. The 3D seismic data, in particular, demonstrate the overall sequence stratigraphy of the basin and lead to a new structural interpretation. This interpretation is based mainly on 3D seismic data. Emphasis is placed on the Lower Permian to Pennsylvanian geologic section where hydrocarbons have been found in tight reservoirs. Currently, these reservoirs are being developed by Conoco Inc. in partnership with Tom Brown Inc. Geographically, the study area is located about 120 miles south of Midland in Texas. It encompasses Conoco's 3D seismic coverage in the Val Verde Basin and occupies an area roughly 30 × 6 miles. Geologically, the Val Verde Basin comprises the southern portion of the greater Permian Basin of mid-continent United States. It lies between the Central Basin Platform to the north and the Marathon Uplift to the south (Figure 1). Figure 1. Location map. Based on 2D seismic …