title: The Description of Shale Reservoir Pore Structure Based on Method of Moments Estimation.
abstract: Shale has been considered as good gas reservoir due to its abundant interior nanoscale pores. Thus, the study of the pore structure of shale is of great significance for the evaluation and development of shale oil and gas. To date, the most widely used approaches for studying the shale pore structure include image analysis, radiation and fluid invasion methods. The detailed pore structures can be studied intuitively by image analysis and radiation methods, but the results obtained are quite sensitive to sample preparation, equipment performance and experimental operation. In contrast, the fluid invasion method can be used to obtain information on pore size distribution and pore structure, but the relative simple parameters derived cannot be used to evaluate the pore structure of shale comprehensively and quantitatively. To characterize the nanoscale pore structure of shale reservoir more effectively and expand the current research techniques, we proposed a new method based on gas adsorption experimental data and the method of moments to describe the pore structure parameters of shale reservoir. Combined with the geological mixture empirical distribution and the method of moments estimation principle, the new method calculates the characteristic parameters of shale, including the mean pore size (mean), standard deviation (σ), skewness (Sk) and variation coefficient (c). These values are found by reconstructing the grouping intervals of observation values and optimizing algorithms for eigenvalues. This approach assures a more effective description of the characteristics of nanoscale pore structures. Finally, the new method has been applied to analyze the Yanchang shale in the Ordos Basin (China) and Longmaxi shale from the Sichuan Basin (China). The results obtained well reveal the pore characteristics of shale, indicating the feasibility of this new method in the study of the pore structure of shale reservoir.
authors.affiliation: College of Energy Resources, Chengdu University of Technology, Chengdu, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Li
authors.affiliation: College of Energy Resources, Chengdu University of Technology, Chengdu, China.|State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, China.
authors.forename: Changcheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: College of Energy Resources, Chengdu University of Technology, Chengdu, China.|State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, China.
authors.forename: Zejin
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Research Institute of Exploration and Development, Daqing Oil Field Company, Daqing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, China.|College of Geophysics, Chengdu University of Technology, Chengdu, China.
authors.forename: Huailai
authors.initials: H
authors.lastname: Zhou
authors.affiliation: College of Energy Resources, Chengdu University of Technology, Chengdu, China.|State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Deng
mesh_terms: D002681:China; D019015:Geologic Sediments / Q000145:classification; D055593:Geological Phenomena; D008903:Minerals; D059206:Natural Gas; D061329:Oil and Gas Fields; D016062:Porosity; D012987:Soil / Q000737:chemistry*
chemical_list: D008903:Minerals; D059206:Natural Gas; D012987:Soil