Jurassic Cotton Valley and Smackover Reservoir Trends, East Texas, North Louisiana, and South Arkansas

Abstract

The stratigraphic and structural framework of the Jurassic Cotton Valley and Smackover in the Ark-La-Tex area can be divided into distinct producing trends, each having predictable characteristics and geographic limits. The main Cotton Valley producing trends are: (1) a semicircular belt of lower Cotton Valley limestone along the west flank of the Sabine uplift in east Texas; (2) a north-trending belt of lower Cotton Valley limestone on the west flank of the East Texas basin; (3) an arcuate belt of blanket sandstones centering in Lincoln Parish, north Louisiana; and (4) a broad circular area of massive fine-grained sandstones covering the general area of the Sabine uplift. Minor Cotton Valley sandstone production is developing on the west flank of the East Texas basin from low-permeability Bossier sandstones. The Smackover producing areas are: (1) updip fault traps along the Mexia-Talco fault system; (2) salt anticlines along the flank of the salt basins; (3) basement structures updip from the salt anticlines and fault system; (4) stratigraphic traps near the Arkansas-Louisiana state line downdip from the salt anticlines; (5) complex graben-fault traps associated with more intense salt features deeper within the basin; and (6) a speculative new trend updip of the Mexia-Talco fault system combining small fault traps and regional updip porosity pinchouts recently discovered by McFarlane Oil in western Henderson County, Texas, in a well with oil flows of over 1,000 bbl per day.