Publication Date

2020

Document Type

Thesis

Committee Members

Robert W. Ritzi, Ph.D. (Advisor); David F. Dominic, Ph.D. (Committee Member); Ernest C. Hauser, Ph.D. (Committee Member)

Degree Name

Master of Science (MS)

Abstract

One of the strategies for reducing the emission of the greenhouse gas carbon dioxide (CO2) and mitigating its accumulation into the Earth’s atmosphere is geologic sequestration (GSCO2). This process might be paired with enhanced oil recovery (EOR) within depleted oil reservoirs to provide an economic incentive for GSCO2. Heterogeneity within reservoirs (e.g. spatial differences in entry pressure, permeability, and porosity) can exert significant influence on the dynamics of fluid flow during EOR and GSCO2, and thus on the ultimate success of GSCO2-EOR. The Western Belt sandstones of the Cypress Formation in the Illinois Basin are candidate reservoirs for GSCO2-EOR. Heterogeneity in the Western Belt reservoir rock was analyzed by quantifying contributions to the variance of log-permeability and porosity that arise from differences in primary depositional factors (grain size and bedding structure) and secondary diagenetic factors (compaction and cementation). The greatest contribution to the variance in log-permeability and porosity arises from the differences in means between grain-size units, including lower very-fine sand, upper very-fine sand, lower fine sand, upper fine sand, and lower medium sand unit types. The variance within these unit types also makes a significant contribution. Differences in mean log-permeability or porosity between types of bedding structures contributes little to the variance, and the grain size and bedding structure factors are relatively uncorrelated. Differences in the amount of diagenetic cementation and compaction do not contribute appreciably to the variance in permeability and porosity. These results are based on a limited number of research-quality rock cores extracted from the Western Belt reservoir. More cores should be obtained and studied in this way to assess the generality of these findings within the Western Belt reservoir.

Page Count

88

Year Degree Awarded

2020


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