A mathematical predictive tool for determining the time to water cone breakthrough in horizontal wells

Production of associated water from the oil wells is a common but undesirable occurrence when the reservoir is underlain by a water layer. If the drawdown exerted on the reservoir exceeds a limiting value, the water cone can become unstable and water can start replacing the oil in the production stream. During past decades, several methods have been proposed in the form of mathematical expressions in determining the time to water cone breakthrough in horizontal wells. In the present work, simple-to-use predictive tool, which is easier than existing approaches, less complicated with fewer calculations, is formulated to arrive at an appropriate estimation of the sweep efficiency to investigate the water cone breakthrough in horizontal oil wells. The results can be used in follow-up calculations for calculating time to breakthrough in a bottom-water-drive reservoir. Results show that the proposed predictive tool has a good agreement with the reported data wherein the average absolute deviation percent found to be less than 2.6%. The proposed simple-to-use approach can be of immense practical value for engineers to have a quick check on the time to water breakthrough in a bottom-water-drive reservoir for wide range of operating conditions without the necessity of any field test trials. In particular, petroleum engineers would find the proposed approach to be user friendly involving transparent calculations with no complex expressions for their applications.