Abstract
Hazebroek, Rainbow, and Matthews proposed a trial-and-error method to determine static reservoir pressure using pressure falloff data for three phases (oil, water, and gas). Using their method, we cannot determine the correct static pressure when the period of the test is not long enough. In other words, even though we can get a straight line, the accuracy is questionable. Other limitations are that the method is for a single layer-the saturations within each bank are assumed to be constant-and the method cannot be used for systems with fractures. A simulation approach using history matching is the most practical method to find the static pressure from field data. This approach can relax the assumptions of the previous method and can include fractures in the system. The methodology of our study was to reproduce the shut-in pressure of the falloff test data obtained from the field by modeling the reservoir and scheduling the test using a simulator. After getting a match between the simulation results and the field test data, we forecast the pressures with the simulator to the extent that the pressures do not change with time. That constant value of pressure is considered the reservoir pressure. The matching is basically a trial-and-error method. However, we are able to generate a general procedure and some clue techniques to drive the simulation results close to the match with the field test data. Once we know how to do the matching, it can be done much faster. The simulation approach can predict the static pressure under conditions including the wellbore storage effect, multilayered system, and a hydraulically fractured well. We obtained a unique static reservoir pressure.
Ariadji, Tutuka (1994). Injection pressure falloff with flooded zone. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1994 -THESIS -A6966.