1Department of Earth and Environment Sciences, University of Texas at Arlington, Arlington, TX 76019, United States
2Porous Media Research Lab, Department of Geology, Kansas State University, Manhattan, KS 66506, United States
3Department of Energy and Mineral Engineering, G3 Centre and Energy Institute, The Pennsylvania State University, University Park, PA 16802, United States
4The Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87544, United States
1Department of Earth and Environment Sciences, University of Texas at Arlington, Arlington, TX 76019, United States
2Porous Media Research Lab, Department of Geology, Kansas State University, Manhattan, KS 66506, United States
3Department of Energy and Mineral Engineering, G3 Centre and Energy Institute, The Pennsylvania State University, University Park, PA 16802, United States
4The Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87544, United States
Received: 20 Dec 2022 – Discussion started: 19 Jan 2023
Abstract. Nano-darcy level permeability measurements of porous media, such as nano-porous mudrocks, are only practically feasible with gas invasion methods into granular-sized samples with short diffusion lengths and thereby reduced experimental duration; however, these methods lack rigorous solutions and standardized experimental procedures. For the first time, we resolve this by providing an integrated technique (termed as gas permeability technique) with coupled theoretical development, experimental procedures, and data interpretation workflow. Three exact mathematical solutions for transient and slightly compressible spherical flow, along with their asymptotic solutions, are developed for early- and late-time responses. Critically, one late-time solution is for an ultra-small gas-invadable volume, important for a wide range of practical usages. Developed as applicable to different sample characteristics (permeability, porosity, and mass) in relation to the storage capacity of experimental systems, these three solutions are evaluated from essential considerations of error difference between exact and approximate solutions, optimal experimental conditions, and experimental demonstration of mudstone and molecular-sieve samples. Moreover, a practical workflow of solution selection and data reduction to determine permeability is presented by considering samples with different permeability and porosity under various granular sizes. Overall, this work establishes a rigorous, theory-based, rapid, and versatile gas permeability measurement technique for tight media at sub-nano darcy levels.
The utilities of tight rock are critically needed in various emerging fields of energy geosciences such as EGS and CCUS, but its ultra-low-permeability is not easily measurable, with a lack of a theory-based, rigorous, and rapid measurement technique at sub-nano darcy levels. For the first time, we resolve this by providing an integrated technique (termed as gas permeability technique) with coupled theoretical development, experimental procedures, and data interpretation workflow.
The utilities of tight rock are critically needed in various emerging fields of energy...
