234 D32. Relevant Topics in Geochemistry (Posters)

Wednesday, 18 October 2023
8:00 AM - 5:30 PM
Hall B

GEOCHEMICAL AND GEOLOGICAL CHARACTERISTICS OF THE UPPER DEVONIAN SHALE IN THE ILLINOIS BASIN

Paper number: 234-3
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

The New Albany Shale holds significant importance due to its potential as an abundant organic-rich source rock for hydrocarbon exploration, contributing to the assessment of regional energy resources and facilitating advancements in unconventional oil and gas extraction technologies. This study aims to analyze the geochemical properties of the Upper Devonian New Albany Shale (NAS) formation in the Illinois Basin, which has become a promising target for hydrocarbon exploration. Analyzing the geochemical properties of the Upper Devonian New Albany Shale (NAS) formation in the Illinois Basin is crucial for assessing its hydrocarbon potential and suitability for effective oil and gas exploration. This research utilized twenty core samples from two drilled wells within the Illinois Basin. Here we employed various geochemical techniques, including total organic carbon (TOC), Rock-Eval pyrolysis, and X-ray diffraction (XRD), to gain deeper insights into the geochemical characteristics of the New Albany Shale. The TOC content in the examined core samples varies from nearly 0 to 8.6 wt.%, with an average of 3.9 wt.%, suggesting very good organic matter content in the New Albany Shale. The average free hydrocarbon content (S1) and the generated hydrocarbon content (S2) values are 1.90 and 17.27 mg HC/g Rock. These results suggest the New Albany Shale has enough potential to produce hydrocarbons in the Illinois Basin. Our samples comprise moderately high hydrogen index values (averaging 376 mg HC/g TOC). It mainly contains type I/II kerogen, indicating New Albany Shale is mixed oil and gas prone in the studied region. The average Tmax value in the examined samples is 438 °C, and the mean calculated vitrinite reflectance (VR) is 0.71% lies early to the peak hydrocarbon generation window. Using X-ray diffraction (XRD), the quantitative mineral composition revealed significant proportions of clays, quartz, and feldspar minerals in the studied core samples. It indicates the New Albany Shale holds a higher amount of ductile minerals relative to brittle minerals. Overall, our findings have great significance and present compelling evidence that the New Albany Shale is a promising prospect for further exploration and evaluation of oil and gas resources in the Illinois Basin.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-395614

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