Abstract: Applicability of Well-Test Analysis Results in Production Forecasting

IAKOVLEV, SERGUEI, Consultant

Practicing petroleum engineers often obtain average values of oil permeability and skin factor from buildup pressure transient data. Then these values are used in production forecasting. Our work shows whether calculated average values of oil permeability and skin factor and a single-layer reservoir model can approximate the depletion performance of a layered reservoir.

We used calculated values of permeability and skin in a single-layer reservoir model to make several production forecasts. We compared them to the production performance of a two-layer reservoir. The agreement between the layered reservoir and its single-layer analogy depends on the accuracy of average permeability and skin estimation and on the contrast in the layer properties.

Overall, even though we may have good estimates of calculated average permeability and skin, a single-layer analogy fails to approximate a layered reservoir performance if the contrast in layer properties is great. The paper gives more detail on the range of contrast in layer properties when single-layer approximation is valid.

AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California