New Type Curves for Modeling Productivity of Horizontal Well With Negative Skin Factors

Abstract

Summary This paper first establishes a comprehensive semianalytical model for a horizontal well in a homogeneous, dual- or triple-porosity reservoir. By taking a negative-skin approach, including Laplace transform, separation of variables, and inverse Laplace transform, we obtain the solutions in a unified formula for both constant-rate production and constant-wellbore-pressure production. In the model, we consider a set of rich boundary conditions, including infinite reservoir and closed or constant-pressure boundary conditions for the top, bottom, and side of the bounded reservoir. Consequently, we plot a series of new standard log-log type curves and make a clear observation of different flow periods (e.g., early radial flow, hemiradial flow, linear flow, and late pseudoradial flow) from negative-skin type curves. We make a comparison between the solutions using the negative-skin approach and conventional solutions, which shows that there are some small differences between the two methods. We also analyze the type-curve characteristics for horizontal-well production in dual- and triple-porosity reservoirs, which shows that the derivative curves are V-shaped for dual media and W-shaped for triple media. Finally, we perform well-test interpretations for a horizontal well with positive skin and a horizontal well with negative skin and bottomwater, which shows that our new model performs well against the real field data.

Study on Skin Factor and Productivity of Horizontal Well after Acidizing with Nonuniform Damage

“…Taking into account a negative skin, Nie et al [17] considered a set of complex boundary conditions and built a comprehensive semianalytical model for a HW in homogeneous or dual-or triple-porosity reservoir, which performed well against the real field data. An and Wu [18] built a semianalytical model for predicting production rate of complex wells in anisotropic reservoirs considering damage to the formation due to the invasion of drilling and well completion, which were expressed by a skin factor.…”

A Semi-Analytical Method for Simulating Two-Phase Flow Performance of Horizontal Volatile Oil Wells in Fractured Carbonate Reservoirs

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Evaluation of Liquid Production and Water Injection Profiles of Horizontal Well by Pressure-Transient Analysis: Field Cases

“…Cheng et al 21 developed a well-test model for the horizontal wells with nonuniform production rate considering the segmented oil production and various skin factors in different production segments by Green's function and Newman's product tool. Nie et al 22,23 established a semianalytical model for horizontal wells in a homogeneous, dual, and triple-porosity reservoir and then developed a time-tracking test method to reduce the well testing costs. Sureshjani et al 24 proposed the procedures to estimate the formation permeability distribution by pressure transient analysis.…”