Speaker
Description
Understanding time-dependent petrophysical and geophysical responses during carbon capture and storage (CCS) is critical for reliable monitoring and long-term storage assessment. This study investigates the evolution of in-situ electrical resistivity and associated pore-scale alterations in carbonate core samples from the Permian Basin under CO₂ storage–relevant conditions. Four core samples, two (S06465, S06468) obtained from the Bureau of Economic Geology (BEG) and two (H3, H4) from Department of Energy (DOE) repositories, were analyzed to quantify changes in porosity, permeability, and pore structure resulting from CO₂–brine–rock interactions.
The experimental workflow was applied to four core samples: H3, H4, S06465, and S06468. Sample H3 was collected from depths of 10,673.5–10,674 ft, H4 from 10,721–10,721.5 ft, S06465 from 9,742 ft, and S06468 from 9,652 ft. Initial petrophysical characterization included helium porosity, Archimedes porosity, gas permeability, and liquid permeability measurements. A 20 wt% NaCl brine was used to represent formation salinity. Nuclear magnetic resonance (NMR) measurements, including quick porosity, T₂, and T₁ analyses, were conducted before CO₂ exposure.
Pore combination modeling was performed using PLS400 equipment to characterize pore structure before and after exposure to supercritical CO₂ (scCO₂). In-situ resistivity measurements were conducted under both 100% brine saturation and partial saturation conditions, where approximately 30% brine saturation and 70% scCO₂ saturation were maintained. Measurements were performed at an elevated temperature (120 °C) to simulate reservoir conditions. Resistivity was continuously monitored for 10 days at 3,500 psia. Following the resistivity experiments, pore-combination modeling was developed using the experimental data to quantify pore-scale changes. Additional characterization techniques, including thin-section analysis, micro-CT imaging, and advanced image segmentation, were employed to evaluate changes in pore structure, including vuggy and matrix porosity, as well as permeability evolution.
Results indicate clear time-dependent petrophysical changes, with an initial increase in porosity observed after 10 days of scCO₂ exposure. However, liquid permeability decreased, likely due to the dissolution and alteration of connected pore pathways. One of the studied samples exhibits low permeability, with values of approximately 0.04 mD. These findings provide one of the first laboratory-scale observations of short-term porosity and permeability evolution in Permian Basin carbonate samples under CCS-relevant conditions.
In-situ resistivity monitoring proved to be an effective tool for developing scalable models applicable to CCUS, CO₂-enhanced oil recovery (CO₂-EOR), and Foam CO₂ huff-and-puff processes. The results support improved oil recovery strategies and contribute to economic feasibility under U.S. Section 45Q tax incentives for CCUS technologies. This integrated and novel workflow enhances pore-scale understanding of mineralization, precipitation, and dissolution mechanisms, providing valuable insights into pore-scale processes that control both hydrocarbon recovery and long-term CO₂ storage capacity. Ongoing experiments extend exposure durations to three months to compare short- and long-term storage behavior relevant to CCS and CO₂-EOR applications, which will be further investigated through detailed pore-scale geochemical modeling using PetraSim/TOUGHREACT.
| Country | USA |
|---|---|
| Green Housing & Porous Media Focused Abstracts | This abstract is related to Green Housing |
| Student Awards | I would like to submit this presentation into both awards |
| Acceptance of the Terms & Conditions | Click here to agree |
