Matt Jones
Unique Reservoir Traits and Maturity Trends in the Wolfcamp Shale, Southern Delaware Basin, Pecos County, Texas
Abstract:
The USGS estimates 29 billion barrels of oil and 109 trillion cubic feet of gas remain undiscovered within the Permian Upper Wolfcamp Formation (Wolfcamp A & B) in the Delaware Basin of West Texas and Southern New Mexico. Despite the recent downturn in industry activity, more than a quarter of active onshore US rigs are drilling in the Delaware Basin, with most drilling horizontally in the tight intervals of organic-rich shale and/or silty sand strata of the Upper Wolfcamp. Successful aerial and vertical targeting of these reservoirs require a detailed understanding of depositional facies, reservoir quality, saturation, pressure, and maturity.
Beginning in the spring of 2017, Gary Permian LLC took leases in the southern part of the Delaware Basin, near Fort Stockton, Pecos County, Texas. A pilot hole was drilled, taking ~400’ of core in basinal and to proximal shelf deposits in the Wolfcamp A and B intervals. Reservoir quality of most lithofacies was similar to values seen in other parts of the basin, however several mudstone beds in the Wolfcamp A contain significant proportions of siliceous sponge material and display much higher reservoir quality and a relative abundance of moldic macropores. The mechanism for the preservation of these large pores is not well-understood, but thought to be due to the presence of amorphous silica inhibiting pore-filling quartz and/or select dissolution of authigenic quartz species. The stratigraphic location and depositional fabric of these beds suggest they may be autochthonous rather than transported from shallower water.
From this same well, Rock-Eval and measured vitrinite reflectance values are inverted relative to increasing depth, with higher maturity values present in the Wolfcamp A relative to the Wolfcamp B. Higher maturity intervals measure comparatively lower in water saturation and higher in porosity and permeability. Analyses of produced oils from these zones indicate catagenesis kinetics of the Wolfcamp A in this area may have been enhanced by higher concentrations of Type IIs kerogen relative to normal marine Type II kerogen.
Biography: Matt Jones
Matt received a B.S. in Chemistry and a M.S. in Geology from New Mexico State University. His graduate thesis focused on opal and calcite beds of mixed geothermal and shallow meteoric origin in fluvial strata of the Ancestral Rio Grande, New Mexico. In 2010, Matt started his career with Devon Energy in Houston, working on special sed/strat studies and exploration in Pennsylvanian sands in the Anadarko Basin. Several years later he signed on with Samson Resources in Denver, where he worked on a wide variety of exploration and development projects in the Powder River, Williston, San Juan, and Greater Green River Basins. Most recently, Matt worked as a Senior Geologist for Gary Permian LLC, where he focused on acquisition opportunities, asset evaluation and development in the Permian Basin of West Texas. In his free time, he enjoys long walks on the outcrop, cycling, and bargaining with his children to put on their shoes.