引用本文:
【打印本页】   【下载PDF全文】   查看/发表评论  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览次   下载 本文二维码信息
码上扫一扫!
分享到: 微信 更多
A computing method of shale permeability based on pore structures
SUN Hai1,2, YAO Jun1, ZHANG Lei1, WANG Chen-chen1, SUN Zhi-xue1, YAN Yong-ping3, PANG Peng3
(1.School of Petroleum Engineering in China University of Petroleum, Qingdao 266580, China;2.School of Geosciences in China University of Petroleum, Qingdao 266580, China;3.Oil & Gas Technology Research Institute of Changqing Oilfield Company, Xi 'an 710021, China)
Abstract:
A modified Darcy 's law with apparent permeability is used to describe the gas transport mechanisms in tight shale rocks, and the apparent permeability can be correlated to the intrinsic permeability and porosity of the rocks, which are difficult to measure using conventional experimental methods. A new computing method for the intrinsic permeability, porosity and apparent permeability of shale was proposed based on the data obtained from pore structure images. Firstly, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the mineral compositions and pore structures of a shale rock sample. Then a 3D digital rock was constructed using the Markov chain Monte Carlo (MCMC) method,and the rock 's parameters, such as intrinsic permeability and porosity, were calculated using the lattice Boltzmann method (LBM). Finally, a model of the correlation between the intrinsic permeability and porosity of the shale rock was established, and the apparent permeability was calculated. The results show that the main pores in the shale matrix can be classified as nano-micro pores. The apparent permeability is found, when the Knudsen number is less than 0.01, to be equal to the intrinsic permeability, and the Darcy 's law can be used. When the Knudsen number is higher than 0.01, the Darcy 's law cannot be used, and the higher the Knudsen number and the smaller the intrinsic permeability and pressure, the bigger the deviation between the apparent permeability and the intrinsic permeability.
Key words:  digital rock  shale gas  lattice Boltzmann method  Markov chain Monte Carlo method  permeability