Late Pennsylvanian (Virgilian) to Early Permian (Leonardian) Conodont Biostratigraphy of the "Wolfcamp Shale", Northern Midland Basin, Texas

Kohn, Jennifer L.; Barrick, James E.; Wahlman, Gregory P.; Baumgardner, Robert W.

doi:10.2110/sepmsp.111.11

Cited by 6 publications

(1 citation statement)

References 63 publications

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“…The Wolfcamp shale formation is located in the Permian basin, a sedimentary basin in western Texas and southeastern New Mexico. Application of horizontal drilling and improved hydraulic fracturing technology has transformed this formation from a nonviable shale play into the largest continuous oil and gas production region in the US, , with potential recoverable resources of 20 billion barrels of oil, 16 trillion cubic feet of natural gas, and 1.6 billion barrels of natural gas liquids according to a US Geological Survey assessment . Using conventional primary recovery technology, hydrocarbon recovery rates are generally less than 10% for oil and approximately 20% for gas .…”

Section: Introductionmentioning

confidence: 99%

Small-Angle Neutron Scattering Investigation of Oil Recovery in Mineralogically Distinct Wolfcamp Shale Strata

et al. 2023

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Understanding and improving hydrocarbon yields during enhanced oil recovery (EOR) in unconventional reservoirs is complicated by the intrinsic mineralogical and geochemical heterogeneity of shale formations. In this study, we utilized small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) to investigate the degree of oil retention and its location in the nanoporous shale matrix for two mineralogically distinct shale samples. The two samples, dubbed “dark” and “light” based on their color, were taken from adjacent strata in a Wolfcamp shale core. While both samples contained kerogen, the dark sample contained more kerogen and clay (43.7 wt %) while the light sample contained more calcite (54.9 wt %). Samples were presaturated with decane, a model hydrocarbon, prior to pressure cycling with methane. Results showed significantly more retention of decane in 1.5–10 nm radius pores of both, likely indicating that oil is retained within kerogen nanopores. Although the dark sample had a higher porosity of 8.7%, versus 3.3% for the light sample, more pores were accessible to decane and a higher percentage of the imbibed decane was removable from the light sample compared to the dark sample. The majority of decane was not recoverable for the dark sample, indicating that EOR with methane can be challenging. These new findings can help to model expected recoveries of in-place oil from heterogeneous shale formations, as well as inform improved EOR strategies.

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