Analytic Two-Dimensional Models of Water Cresting Before Breakthrough for Horizontal Wells

Summary Production with horizontal wells offers a new approach to reducing water-coning effects during oil production. This paper evaluates what effect water cresting under a horizontal well will have and determines the critical flow rate by fully analytic, two-dimensional (2D) methods developed in a vertical plane perpendicular to the axis of the horizontal well. Three production mechanisms are considered: lateral edge drive, gas-cap drive, and bottomwater drive. The theory gives the critical flow rate value in each case. A major achievement of this theory is the proof of a decreasing critical flow rate value with cumulative production by the bottomwater-drive mechanism. Results are presented in graphs for quick use. Case studies exemplify a simple evaluation method to help solve practical engineering problems.