Analysis Of Drainage Area In Shale Gas Formation Of Multi-well Pressure Interfere With Fast Marching Method

Shale gas reservoirs are developed using fracturing horizontal wells by factory operations,and the pressures propagate from different horizontal wells to interfere with the effective exploitation of shale gas reservoirs.Therefore,it is very important to study the development of reservoir under the condition of multi-well disturbance to guide the development of shale gas reservoir.In order to solve the problem of the evaluation of the degree of drainage,this paper predicts the propagation of pressure wave front in the reservoir at different time under the condition of multi-well interference in shale gas reservoir based on fast marching method(FMM).Based on the calculation principle of FMM,the equation of pressure wave migration of shale gas reservoir under multi-well disturbance is established,and the method of solving the equation is improved to realize the application of FMM in heterogeneous reservoirs.Considering the slippage flow and adsorption and desorption characteristics of shale gas reservoirs,the method of evaluating the degree of utilization in orthogonal grids reservoir is put forward,and the degree of utilization in unstructured grids is also proposed to simulate the flow of fluid in different media on the basis of the discrete fracture model(DFM).The pressure calculation model based on time of flight is established,meanwhile production evaluation method based on FMM is put forward after obtaining the degree of utilization.Based on the evaluation method of reservoir utilization degree,the influencing factors of multi-well use degree are analyzed,such as the positive situation,horizontal well spacing,half length of hydraulic fractures,conductivity of hydraulic fractures,permeability and fracturing level.The pressure prediction and the composition analysis of the shale gas reservoir under the conditions of multi-well production are carried out,and the field examples are analyzed and studiedThe results of this paper are of significance for the field operation for shale gas reservoirs and the parameter optimization of multiple fracturing horizontal wells.