A New Approach for Computing Pressure Derivative in Well Test Analysis

Abstract Analysts commonly use the pressure derivative to identify flow regimes and well test interpretation models in pressure-transient test analysis. This article developed a novel adaptive smoothing algorithm by recursive differentiation–integration to improve the pressure derivative calculation. Our method can efficiently suppress measurement errors and produce smooth pressure derivatives from well test data. Equally important, it can prevent oversmoothing of the data by avoiding inappropriate use of large window size, and it can preserve the characteristic behavior of the pressure derivative. We validate our approach with a synthetic case and demonstrate its applicability to actual field examples.