The Establishment of Numerical Well Testing Modeling and Sensitivity Analysis in Fractured Basement Reservoir

The dual porosity model is always applied in pressure transient well testing interpretation of fractured basement reservoir and there is no direct correlation between the interpretation results and fracture characteristic parameters. Fractures are important in fluid storage and flowing in basement reservoir, more details and information are needed in fractured reservoir well testing interpretation to guide the oil field development. The numerical well testing modeling is designed to solve the well testing interpretation problems in reservoir with regular fractures. But precise numerical well testing modeling of a dense system of randomly spaced, randomly distributed and oriented, interconnected and unconnected fractures would be very challenging. The numerical well testing modeling can simulate the impacts of well-hole connectivity, dip angle and fracture width on the interpretation results. It is supposed that the parameters in the regular fracture system that do not affect interpretation results do not work in nature fracture system. With this hypothesis, imaging logging data of 3 wells are selected to determine the fracture width, density and azimuth to calculate the fracture porosity and effective permeability and to build the simulation model. The pressure simulated from the model matches the pressure response of actual filed well testing and the effective permeability matches the real one too, which indicates that random fracture system can be replaced by simplified regular fracture system in this study to lower simulation difficulty. The sensitiveness of fracture parameters is also studied in this paper.