Prediction method of reservoir pore types based on pore shape substitution
Zhang Jia-Jia ♦1,2, Chen Kang 3, Zhang Guang-Zhi 1,2, Di Gui-Dong 3, Xu Lei-Lei 4, and Gu Yi-Peng 1,2
1. School of Geosciences, China University of Petroleum (East China), Qingdao 266580, China
2. Key Laboratory of Deep Oil and Gas Geology and Exploration, Ministry of Education, Qingdao 266580, China
3. Research Institute of Exploration and Development, PetroChina Southwest Oil and Gas Field Company, Chengdu 610041,China
4. The 7th Institute of Geology & Mineral Exploration of Shandong Province, Linyi 276000, China
Abstract：
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.
2021, Vol. 18 
