ANALYSIS OF TWO-PHASE FLOW PRESSURE BUILDUP DATA FROM WELL IN AN INFINITE MULTIWELL RESERVOIR

A general method has been developed for analyzing two-phase flow pressure buildup data from a well located in a system of both production and injection wells completed in an infinite multiwell reservoir. The analysis technique assumes that the tested well has established its own drainage area before shut-in and a linear reservoir pressure trend dominates the well pressure behavior at the instant of shut-in. And for the two-phase flow problems the horizontal saturation gradients are assumed to be negligible. The entire pressure response, whether or not conventional semilog straight lines exist, can be analyzed and the Injection-Production Ratio (IPR), the total fluid (oil/water) mobility, the average drainage-area pressure, and also the skin factor can be calculated much easily. The validity and applicability of the method are demonstrated by a field example. The technique by using the type curves for analyzing the pressure-buildup data is also presented here.