Research On Stochastic Simulation Method Combined With Well Test Data

The key of the stochastic simulation method in reservoir is establishing the geological model.Well test is one of the methods to understand reservoir dynamics and can be used to evaluate the production dynamics of oil and gas reservoir.However,the established geological model is mainly based on static geological data,ignoring the dynamic data of the well test.In this paper,hence,a stochastic simulation method based on well test data and conventional geological modeling method was presented,which makes the obtained newly model match well with the real reservoir.Firstly,the principles and implementation processes of three commonly used stochastic simulation methods were introduced in this paper.Three commonly used stochastic simulation methods are sequential Gauss simulation method,sequential indicator simulation method and simulated annealing method.In addition,reservoir physical parameters were simulated by SGSIM,SISIM and SASIM programs in Geostatistical Software Library(Gslib),and the initial reservoir model was established based on it.Secondly,according to the principle of simulating annealing algorithm,and combine the well test data to set up annealing target function.That is the function of pressure and the initial parameter field of disturbance,so that the pressure of new model is matched with well test pressure.Due to the variation of parameters field when disturbing the initial parameters field,it is impossible to simulate every parameter field in real time.Therefore,the physical mathematical percolation mode of eccentric well in the two zone composite reservoir is put forward to and solved and verified.This analytical solution is used to replace the simulated value of the numerical simulation.Moreover,because the variables calculated by mean value were not accurate enough in the analytical solution,so we need to correct the reservoir pressure by simulating that it can reduce the number of numerical simulation and time.In conclusion,the stochastic simulation procedure of the dynamic data testing have been compiled in combination of Fortran.Though disturbing initial parameter field to make the objective function be minimum and stop disturbance.Then,outputting the new parameters field matching with dynamic well test data.Finally,the example verification is carried out.The feasibility of the stochastic simulation method combined with the dynamic data of well test is verified by the ideal 5 point well group model and the reservoir well group model of S Oilfield.