A NEW SEMIANALYTICAL PRESSURE TRANSIENT MODEL TO INTERPRET WELL TEST DATA IN RESERVOIRS WITH LIMITED EXTENT BARRIERS

Due to the lack of enough models to interpret transient well test data in reservoirs with limited baffles/faults, a novel semianalytical model is developed in this study based on the concepts of imaginary wells and superposition in time and space. The proposed model was validated by comparing its results with outcomes of a numerical well test simulator, and statistical parameters such as root mean square error (RMSE) analysis, residual plots, and the R-squared parameter were used to verify the accuracy of the model. Furthermore, a sensitivity analysis was performed over the length of the fault and the distance of the fault from the wellbore. Although RMSE for the derivative data varies between 0.5 and 9 psi for various fault and well scenarios, it varies between 2.88 and 26 psi for the pressure drop data. Residual data scattered around the zero horizontal line and R-squared values larger than 0.99 revealed the robustness of the proposed algorithm. To reduce the computational time, a logarithmic function was applied to distribute the imaginary wells along the limited fault. Ultimately, the developed model can be embedded into commercial well test software where there is a lack of limited fault models to analyze the pressure transient data.