Graduation Semester and Year
Fall 2024
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Earth and Environmental Science
Department
Earth and Environmental Sciences
First Advisor
Dr. Majie Fan
Second Advisor
Dr. Qinhong Hu
Abstract
The New Albany Shale (NAS) in the Illinois Basin is an important organic-rich source rock for hydrocarbon production, making it essential to understand its complex geochemical, petrophysical, and fluid migration characteristics for efficient exploration and resource management. However, NAS poses several challenges due to its heterogeneous nature, low porosity, intricate mineral composition, and the need for an integrated approach that addresses organic matter enrichment, pore structure, and fluid migration dynamics. Existing studies often focus on isolated aspects, leaving a gap in comprehending the full range of factors influencing the reservoir potential of NAS. This study bridges these gaps by employing a multi-approach methodology that combines geochemical, petrophysical, and fluid migration analyses across different lithofacies to achieve a comprehensive characterization of NAS.
Geochemical analysis reveals substantial total organic carbon content, predominantly Type I/II kerogen, and early to peak-stage thermal maturity, affirming NAS as a viable hydrocarbon source rock. By examining paleoenvironmental factors, the study identifies paleoclimate, paleoproductivity, paleoredox conditions, and hydrothermal activity as crucial influences on organic matter enrichment. Variations of these factors and hydrographic restriction shaped the depositional environment of NAS, contributing to organic production and preservation and enhancing its source rock potential.
A petrophysical assessment of NAS reveals significant heterogeneity in pore structure and distribution across its lithofacies: NAS-1 (Organic-Rich Laminated Quartz-Bearing Argillaceous Shale), NAS-2 (Organic-Fair Non-Laminated Calcareous Shale), and NAS-3 (Organic-Rich Laminated Clay-Bearing Argillaceous Shale). Using techniques such as scanning electron microscopy (SEM), nitrogen physisorption, small angle x-ray scattering (SAXS) and X-ray diffraction, the study identifies variations in pore morphology, with inkbottle-shaped pores in NAS-1 and NAS-2 and wedge-shaped pores in NAS-3. Mesopores (pore diameters at 2-50 nm) and macropores (>50 nm) are significant contributors to the overall pore system, influenced by mineralogical composition. Microfractures associated with organic matter and brittle minerals further enhance fluid migration potential, especially in NAS-2, underlining the importance of lithofacies-specific attributes in reservoir evaluation.
Fluid migration analysis investigates the characteristics of pore connectivity, wettability, and tracer migration across NAS samples, focusing on both hydrophilic and hydrophobic pore networks. Mercury intrusion porosimetry (MIP), contact angle measurements, and tracer experiments reveal a preferential flow for nonpolar fluids (such as oil) over polar fluids (such as brine), with hydrophobic pores exhibiting superior connectivity. This behavior is further supported by spontaneous imbibition experiments and contact angle data, which show higher connectivity slopes for nonpolar fluids. Findings indicate that hydrophobic pore networks play a dominant role in fluid migration, critical for enhancing hydrocarbon extraction efficiency and optimizing production strategies in shale reservoirs.
This dissertation integrates geochemical, petrophysical, and fluid migration analyses to present a holistic understanding of the reservoir potential of the NAS. By adopting a multi-scale, multi-analytical approach, the study not only addresses limitations in previous research but also offers valuable insights for hydrocarbon exploration and economic assessment of shale resources in the Illinois Basin.
Keywords
hydrocarbon exploration; paleoproductivity; pore connectivity; lithofacies; pore connectivity
Disciplines
Data Science | Earth Sciences | Natural Resources and Conservation | Oil, Gas, and Energy | Other Environmental Sciences | Sustainability
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Iltaf, Khawaja Hasnain, "MULTI-APPROACH GEOCHEMICAL AND PETROPHYSICAL CHARACTERIZATION OF THE NEW ALBANY SHALE IN THE ILLINOIS BASIN" (2024). Earth & Environmental Sciences Dissertations. 91.
https://mavmatrix.uta.edu/ees_dissertations/91
Included in
Data Science Commons, Earth Sciences Commons, Natural Resources and Conservation Commons, Oil, Gas, and Energy Commons, Other Environmental Sciences Commons, Sustainability Commons