Detection of pressure buildup data dominated by wellbore phase redistribution effects

This paper presents a new diagnostic technique that detects the presence of any type of phase redistribution pressure response and determines the true beginning of the semilog straight line for conventional analysis techniques. The method can also be used to predict the end of any wellbore effects. This greatly enhances the conventional analyses and yields more accurate estimation of the reservoir parameters. The technique is based upon existing analytical solutions for radial flow in homogenous reservoirs. oposed method is simple and straightforward. It does not require manual or automatic type curve matching and it does not use complicated nonlinear optimization or history matching as some other methods necessitate. The applicability and accuracy of the proposed method are demonstrated through the analysis of three simulated cases and two field examples.