A calculation method for the pressure behavior response of horizontal well in anisotropic reservoirs at variable flow rate

Offshore oilfields are lack of high-precision pressure monitoring data. In order to solve this problem by applying the historical production data and transient well test method to evaluate and predict horizontal wells in anisotropic reservoirs, the pressure behavior response relation of horizontal well in anisotropic reservoirs at variable flow rate was established based on the three dimension point source function of horizontal well and the Newman product principle. Then, this relation was discretely transformed into the pressure response well test model of horizontal well at variable flow rate in the form of convolution and matrix which is practically applicable. Finally, the solution was calculated by means of the optimization algorithm. It is indicated that this model can be used to evaluate the production performance of horizontal wells and determine the number of the series terms constituting the point source function of horizontal well in the process of calculation, and the model parameters determined by the optimization algorithm can be also used for production performance prediction. Field application results show that the calculation results of the pressure behavior response model of horizontal well at variable flow rate is accordant with the actual production performance, and the average relative error is 3.1%. The research results are practically of instructive significance to evaluate the oil reservoir characteristics of horizontal wells and predict the development and production of horizontal wells.