Volume 9: Sustainable Energy Solutions for Changing the World: Part I

Genetic algorithm-based interpretation of shale core matrix-natural fracture parameters Jian-Yi Liu, Lu Jiang, Shan Yi , Miao Liu, Zhi-Bin Liu, Xue-Ni Dai, Yi-Zhao Chen, Yang Xie

Abstract

Shale pore-seepage parameters are the basic data for evaluating the seepage ability of shale formation. Due to the low-seepage characteristics of shale, only pulse attenuation method can be used to accurately test shale permeability.Various experimental results show that shale has distinct dual-pore characteristics, and conventional pulse attenuation method can only test the overall permeability and total porosity of shale.Based on the dual-hole characteristics of shale, this paper establishes a non-steady seepage model in shale matrix-natural cracks, solves it by Laplace transformation and fits it by genetic algorithm, and obtains an interpretation method for both shale matrix and natural fracture pore-seepage parameters by a set of data.This method can be used not only for the forward analysis of the pulse attenuation pressure response characteristics, but also for testing the pore and seepage parameters of natural fractures in shale core matrix by fitting experimental data.The correlation coefficients R2 of the two groups of experimental data were 0.9953 and 0.9996 respectively, and the fitting results were good.

Keywords Genetic algorithm, Well Test interpretation, Shale Core, Permeability testing