Gas flow regimes judgement in nanoporous media by digital core analysis
Song Wenhui,
Liu Hua,
Wang Weihong,
Zhao Jianlin,
Sun Hai,
Wang Dongying,
Li Yang,
Yao Jun
Affiliations
Song Wenhui
State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development; Research Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Dongying, China
Liu Hua
State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Sinopec Petroleum Exploration and Production Research Institute, Beijing, 100083, P.R.China
Wang Weihong
State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Sinopec Petroleum Exploration and Production Research Institute, Beijing, 100083, P.R.China
Zhao Jianlin
Research Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Dongying, China
Sun Hai
Research Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Dongying, China
Wang Dongying
Research Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Dongying, China
Li Yang
Department of Oilfield Exploration & Development, Sinopec, China
Yao Jun
Research Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Dongying, China
A method to judge shale gas flow regimes based on digital core analysis is proposed in this work. Firstly, three-dimensional shale digital cores in an anonymous shale formation in the Sichuan Basin are reconstructed by a Markov Chain Monte Carlo (MCMC) algorithm based on two-dimensional Scanning Electron Microscope (SEM) images. Then a voxel-based method is proposed to calculate the characteristic length of the three-dimensional shale digital core. The Knudsen number for three-dimensional shale digital cores is calculated by the ratio of the molecular mean free path to the characteristic length and is used to judge the flow regimes under different reservoir conditions. The results indicate that shale gas flow regimes are mainly located at the slip flow and transition flow region. Furthermore, adsorption has no obvious influence on the free gas flow regimes. Because adsorption only exists in organic pores, three-dimensional inorganic pores and organic pores in the Haynesville shale formation are reconstructed by a MCMC algorithm based on two-dimensional SEM images. The characteristic lengths of the three-dimensional inorganic pores and three-dimensional organic pores are both calculated and gas flow regimes in organic pores and inorganic pores are judged.
