Fuzzy Structural Element Method for Solving Nonlinear Fuzzy Seepage Model of Shale Gas Reservoir

Abstract

Shale gas reservoir refers to a new alternative energy. The percolation of shale gas reservoir is more complicated than that of conventional power for its unique reservoir forming characteristics and physical properties. Accordingly, to produce shale gas reservoirs in a large scale, the percolation of shale gas reservoirs should be better simulated. The conventional seepage model of shale gas reservoir assumes that reservoir permeability is a specified value. However, reservoir is usually significantly uneven and complex, suggesting that considering the permeability as a fixed value will reduce the accuracy of the model. Given this, the concept of fuzzy permeability is proposed here. On that basis, the fuzzy non-linear seepage model is established. To avoid the ergodic operation of the conventional fuzzy differential equation solving method, this study employed the fuzzy structural element method to solve the new model. Also, given the practical application problems, the fuzzy solution set is further non-fuzzy treated using the centroid method. Finally, the superiority of the nonlinear fuzzy seepage model is illustrated by the comparison between the nonlinear fuzzy seepage model and the conventional nonlinear seepage model.