Title: Influence of relative permeability, capillary pressure, and well orientation in the geological carbon sequestration in a saline aquifer

Authors: Abhishek Gupta; Akshoy Ranjan Paul

Addresses: Department of Applied Mechanics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj-211004, India ' Department of Applied Mechanics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj-211004, India

Abstract: In carbon capture and sequestration (CCS), geological sequestration of carbon dioxide (CO₂) in deep saline aquifers with porous and permeable rocks is one of the most feasible among various solutions to sequester CO₂. Here, the TOUGH2 numerical simulator was validated with the analytical model developed predicting the CO₂ behaviour in confined saline aquifers. The sensitivity of the numerical model was examined by changing the model of fluid relative permeability (RP) and capillary pressure (CP) functions. Corey's RP functions and Van Genuchten's CP function is most effective to capture the gas saturation (SG) well. The effect of CO₂ injection, well orientation, and its length in a simplified saline aquifer model are also demonstrated. This study reveals that the horizontal well configuration is most acceptable. For the same injection well length (at 100 m), 22% drop in the pressure rise is computed in horizontal well as compared to its vertical counterpart. [Received: October 9, 2021; Accepted: February 7, 2022]

Keywords: carbon capture and sequestration; CCS; CO₂ geological sequestration; saline aquifers; relative permeability; capillary pressure; well orientation.

DOI: 10.1504/IJOGCT.2022.126360

International Journal of Oil, Gas and Coal Technology, 2022 Vol.31 No.3, pp.263 - 279

Received: 08 Oct 2021
Accepted: 07 Feb 2022
Published online: 24 Oct 2022 *