3D STRUCTURAL MODELING OF THE FORT WORTH BASIN IN TEXAS

The Fort Worth basin with an area of 54,000 square miles (120,000 km²) is located in the north central part of Texas. It consists of the largest producible onshore gas reservoirs in the United States with current production rate of about 200×10⁶ cu ft/d. The Fort Worth basin is bounded by the Ouachita thrust belt to the east, the Red River and Muenster uplifts to the north, the Llano uplift to the south, and is separated from the Permian Basin to the west by the Bend Arch. The basin is a peripheral foreland basin of the Ouachita thrust belt, which formed as a result of Gondwana and Laurasia continental collision during Late Mississippian and Permian time. The axis of the basin trends almost N-S direction, parallel to the eroded and covered Ouachita thrust belt to the east. It has an asymmetric shape and its depth increases to ca. 12,000 ft (3,800 m) toward the northeast, adjacent to the Ouachita deformation front and the Muenster compressional structures. In this study, we used 100 borehole data, structural maps of the Paleozoic formation tops derived from sub-surface data, and one available seismic section to model the 3D structural evolution of the basin. The results enable us to observe and investigate 3D bending deflection, flexural strength, and geometry change of the basin through the Paleozoic. Our results also reveal dynamics and influence of the Muenster uplift and the Ouachita orogen on formation and subsidence history of the Fort Worth basin, and have implications for future hydrocarbon exploration.