A New Semi-Iterative Well-Test Matching Method Based on Featured Points for Homogeneous Reservoir

Abstract The accurate inversion of reservoir parameters is of paramount importance for the successful production of oil and gas. The well test is an important technique for achieving accurate reservoir parameter inversion. However, the challenge of balancing inversion accuracy and speed is present in existing well-test analysis. To tackle this challenge, two homogeneous well-test models with single and dual-porosity media are first presented for the study. Then, a new semi-iterative model (SIM) is used for well-test curve matching method based on featured points of these two well-test models. Furthermore, this study continues to compare the performance of the SIM, the formula-based analytical model (FAM), and the full-iterative model (FIM). It is found that the SIM can be more efficient and accurate to invert the parameters of homogeneous reservoir, because it can integrate the analytical and iterative inversion for each parameter. In addition, the analytical solution formulas for the storage capacity ratio and the interporosity flow coefficient in dual-porosity model are improved using the curvilinear method to achieve higher inversion accuracies. It is found that the median relative errors of parameter inversion for both single and dual-porosity media reservoirs are approximately 0.10% and 0.51%, respectively. The mean time for the SIM model to achieve both parameter inversion and matching of the well-test curves for the two aforementioned models is 2.36 seconds and 251.30 seconds, respectively. The time required for manual fitting methods that rely on human experience is reduced by approximately 90% or more. The results demonstrate that the SIM model proposed in this study is an accurate and efficient method for matching well-test curves of homogeneous reservoirs.