Stanley T. Paxton

Upper Devonian–Mississippian stratigraphic framework of the Arkoma Basin and distribution of potential source-rock facies in the Woodford–Chattanooga and Fayetteville–Caney shale-gas systems

Wireline logs were used to document the stratigraphic framework of Upper Devonian–Mississippian strata in the Arkoma Basin, and maps of high-gamma ray (HGR) log response were used to analyze the spatial distribution of potential source rocks in the Woodford–Chattanooga and Fayetteville–Caney shale-gas systems. The Woodford–Chattanooga shale is a transgressive deposit that accumulated on an arid continental margin influenced by marine upwelling and minimal sediment influx. A broad HGR depocenter along the southwestern margin of the basin includes two areas of higher accommodation containing the thickest HGR concentrations. Basin-wide patterns of HGR likely reflect broad tectonic influence on accommodation. The proportion of chert in the formation increases eastward and southward, likely reflecting latitudinal and bathymetric influence on the accumulation of siliceous ooze. The Lower Mississippian Burlington sequence, which lies between the two shale-gas systems, comprises carbonate ramp and distal shale deposits. Proximal ramp facies form an apron around the southern flank of the Ozark uplift and grade radially basinward into distal facies. An Upper Mississippian succession in the east includes lowstand deposits of the Batesville delta, which onlap the relict Burlington ramp. Basinwide, the succession includes the transgressive Fayetteville–Caney shale overlain by regressive deposits of the proximal Pitkin Limestone and distal upper Fayetteville (Arkansas) and “false” Caney (Oklahoma) shale. The HGR shale is concentrated in an area of intermediate accommodation on the western margin of the Mississippi Embayment and just basinward of the Pitkin Limestone pinchout in Arkansas, and in an area of relatively high accommodation in Oklahoma.

Assessment of undiscovered oil and gas resources in the Eagle Ford Group and associated Cenomanian–Turonian Strata, U.S. Gulf Coast, Texas, 2018

The U.S. Geological Survey (USGS) assessed undiscovered, technically recoverable hydrocarbon resources in self-sourced continuous reservoirs of the Upper Cretaceous Eagle Ford Group and associated Cenomanian–Turonian strata, which are present in the subsurface across the U.S. Gulf Coast region, Texas (fig. 1). The USGS completes geologybased assessments using the elements of the total petroleum system (TPS), which include source rock thickness, organic richness, and thermal maturity for self-sourced continuous accumulations. Assessment units (AUs) within a TPS are defined by strata that share similar structural and petroleum-charge histories along with lithology and stratigraphy.

Assessment of undiscovered oil and gas resources in sandstone reservoirs of the Cotton Valley Group, U.S. Gulf Coast, 2015

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered mean volumes of 14 million barrels of conventional oil, 430 billion cubic feet of conventional gas, 34,028 billion cubic feet of continuous gas, and a mean total of 391 million barrels of natural gas liquids in sandstone reservoirs of the Upper Jurassic–Lower Cretaceous Cotton Valley Group in onshore lands and State waters of the U.S. Gulf Coast region.

ABSTRACT: Downstream Fining of Sediment in a Modern Fluvial System: Lessons from the Canadian River Drainage, Oklahoma, USA, and Implications for Regional Reservoir Performance

Developments in regional reservoir-quality technology suggest that prediction of porosity/permeability in ancient clastic deposits requires better pre-drill estimates of sandstone composition and texture. Toward this end, we are evaluating a series of topographic analysis tools for describing the character of modern fluvial systems for input to reservoir models. Our intent is to demonstrate for the Canadian River drainage that texture and composition of sand varies predictably as functions of 1) distance of sediment transport, 2) bedrock lithology, and 3) changes in stream gradient.