Prediction method of reservoir pore types based on pore shape substitution

• 作 者: Zhang Jia-Jia Chen Kang Zhang Guang-Zhi Di Gui-Dong Xu Lei-Lei Gu Yi-Peng
• 机 构: School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China;Key Laboratory
• 出 处: 应用地球物理（英文版）
• 发表日期: 2021年1期
• 关键词: pore shape pore shape substitution multiple-porosity variable critical porosity

Carbonate, tight sandstone, and shale reservoirs have many pore types, and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape. This paper presents a method for predicting reservoir pore types based on pore shape substitution. The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape, assuming there are no changes in terms of minerals, porosity, or fluids. By employing a multiple-porosity variable critical porosity model, the effective pore aspect ratio could be inverted from the velocities of the rock. To perform pore shape substitution, we could replace the effective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of different pore shapes. The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape. The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the effects of the pore shapes from the effects of the minerals, porosity, or fluids on the velocities.