Pressure buildup techniques applied to identify decreasing fracture stimulation performance

Fracture stimulation characteristics were measured and studied for changing behavior over a 6 month period using pressure buildup tests conducted on a Prudhoe Bay well. The suite of pressure tests included a pre-frac buildup, and two post-frac buildups at six month intervals following the fracture stimulation treatment. Pre-frac analysis exhibited radial composite characteristics consistent with other Prudhoe Bay well test analysis. Post-frac analysis showed the fracture length and conductivity to decrease over a six month period. Corroborating the well test results, production from this well decreased more rapidly than expected. Numerical simulation confirmed the results. Data acquisition pertinent to a successful well test analysis is discussed.