CLINTON CORE ANALYSIS - REVIVING AN OLD OIL FIELD PLAY AS CCUS & EOR GAIN MOMENTUM

Discovered in 1907, the 445-square-mile Gore Consolidated Oil Field in southeast Ohio contains over 12,000 vertical wells of which the primary targeted interval is the lower Silurian-aged Grimsby Sandstone or more commonly known as the “Clinton Sandstone.” While heavily drilled and studied early on, the Gore Field has had a steady decline in production over the past century with ~1,600 actively producing wells today. In light of the recent interest for carbon capture, utilization, and storage (CCUS) in legacy oil fields in the United States, the Gore Field has become a potential candidate for enhanced oil recovery (EOR), and a detailed understanding of the reservoir geology is crucial for it to be a successful CO₂ EOR. Recent studies assessing the Gore Field exhibit ideal economics, cost analyses, CO₂ miscibility, but lack an updated, in-depth geology piece. Potentially favorable reservoir characteristics are however examined in other nearby Clinton fields in Ohio, such as the East Canton Oil Field. Examining 12 Clinton sandstone cores, this new research takes a fresh look at all existing core data combined in one study, utilizing existing geophysical well-log data, adding new, detailed core descriptions, and incorporating new Computed Tomography (CT) scans and X-Ray Fluorescence (XRF) data from the cores to better characterize the Clinton sandstone geology and reservoir quality within the field. Early data results from CT scans more clearly show a plethora of marine trace fossils present in the core, more precisely indicating likely environments of deposition, and also variations in the rock, such as cementation. The XRF data has helped to better calibrate core data to the original wellbore geophysical log through the calculation of a spectral gamma log. The XRF and CT data also show subtle shifts in lithologies throughout the core and areas with higher clay content, calcite, and varying cements. In conclusion, this new study aims to do a full field-scale analysis, helping to further understand the complexity of the Clinton reservoir quality and provide critical information necessary to plan a successful CO₂ EOR effort within the Gore Field.