Effective Model to Evaluate the Inflow Performance of Highly Deviated Wells in Anisotropic Reservoirs

Abstract

Inflow performance evaluation is an important basis for the completion design of highly deviated wells, but existing evaluation models do not consider reservoir anisotropy or well deviation angle with long calculation time and certain limitations. In order to perfect the inflow performance evaluation model of highly deviated wells, a high-efficiency model evaluating their inflow performance in anisotropic reservoirs was proposed in this study. On the basis of a source function method, an oil reservoir-wellbore coupling flow equation was established, and a new model that can evaluate inflow performance of highly deviated wells in anisotropic reservoirs was proposed by introducing the anisotropic quantitative characterization method. On this basis, the influence laws of anisotropy and well deviation angle on inflow morphology, potential section, and productivity of highly deviated wells were discussed. Results indicate that the new model can consider the influences of reservoir anisotropy and well deviation on inflow performance, and the calculation only consumed 1/30 of the traditional model. Reservoir anisotropy has a great influence on the inflow performance of highly deviated wells. The smaller the anisotropy coefficient, the earlier the transient-state flow appears in the transition phase, and the later the steady-state flow appears in the subsequent phases. Anisotropy coefficient has an apparent influence on flow velocity in the wellbore, and flow rates at two ends of the wellbore decrease by 32.3% when the anisotropy coefficient increases from 1/100 to 100. The influence of well deviation angle on the highly deviated well production is enhanced as the anisotropy coefficient increases. The study contributes to the highly efficient evaluation of the inflow performance of highly deviated wells and provides a certain reference for the optimization of highly deviated wells and production forecast.

Analysis of Gas Flow Behavior for Highly Deviated Wells in Naturally Fractured‐Vuggy Carbonate Gas Reservoirs

“…In a recent work, Meng et al proposed a semianalytical model of HDW for evaluating the pressure behavior which considered the stress-sensitive performance in fractured-vuggy carbonate gas reservoirs with composite systems [27]. Zhao et al built a new model for evaluating inflow performance of HDW in anisotropic reservoirs, which was proposed by introducing the anisotropic quantitative characterization method [28].…”