Dynamic Test Data Are Used To Predict The Production Capacity Of Low-permeability Reservoirs

The precise evaluation of reservoir productivity is of great significance for the exploration and development of offshore oil and gas fields.Production capacity is a comprehensive dynamic parameter that describes the status of oil and gas reservoirs and development engineering,and is an indicator that reflects the dynamic balance between the production potential of reservoirs and various engineering factors.Productivity prediction is to analyze factors affecting productivity and calculate relevant parameters in combination with reservoir data and means of production of various production wells and exploration wells,so as to finally achieve the purpose of predicting future production of reservoirs.The accuracy of production capacity prediction directly affects the rationality of oil and gas field development plans,so precise production capacity evaluation can improve the economic benefits of oil and gas field exploration and development.The effective permeability and skin coefficient are key parameters for productivity prediction.This article uses MDT formation testing data combined with phase permeability models to calculate the effective permeability of single-phase and two-phase gas reservoirs;Analyze the impact of different operating conditions on the skin factor in the research area,and use the pressure data from MDT testing combined with the unstable well testing method to calculate the total skin factor.The optimal parameters are divided into two categories: dynamic parameters obtained from DST well testing and MDT formation testing,and static parameters obtained from logging,and the methods for obtaining relevant parameters are provided.The absolute open flow rate and gas production index of the gas well are used as quantitative parameters to describe the production capacity,and the gas production index is used as the output parameter of the established model.Finally,the support vector machine method is used to combine dynamic and static parameters,as well as permeability and skin coefficient to establish a suitable production capacity prediction model for the research area.The main achievements and understanding achieved are as follows:(1)The theoretical relationship formula for calculating the effective permeability of pure gas reservoirs and gas-water two-phase gas reservoirs based on MDT pressure drop flowrate and pump pumping flowrate has been verified through error verification with DST permeability testing,proving that this method is feasible and effective.(2)According to the statistical analysis of skin coefficient in this research area,the use of oil-based mud can reduce reservoir pollution;The smaller the nozzle,the smaller the production capacity pollution;The skin coefficients of different flow modes can be summarized as linear flow<radial flow<spherical flow;In this study area,the skin coefficient of straight wells is generally larger than that of inclined wells.The skin coefficient calculation method proposed in this article has been proven feasible and can reduce costs through error analysis with DST well testing reports.(3)Comparing the results obtained from the productivity prediction model established in this article with the DST well test report,it can be concluded that the error is controllable and the productivity value of new wells can be predicted.This method is feasible.