Interference testing with horizontal wells in layered reservoir

Interference testing with horizontal wells has become a valuable tool for characterization of heterogeneous reservoirs. However, the current methods of analysis of interference tests with horizontal wells in layered system use single-layer homogeneous model. This can result in significant errors in the estimated average reservoir properties. This paper presents the results of a study carried out to investigate the effect of layering on the pressure response at the observation well in horizontal well interference testing in a two-layer reservoir. A numerical approach is employed to study the effect of parameters like omega, kappa, vertical permeability and distance between the horizontal wells on observation well pressure response in an interference testing with horizontal wells in a two-layer reservoir. The results of the study show that the observation well pressure response form interference testing in two-layer system deviates from the equivalent single-layer system response. This deviation depends on the contrast in transmissibility and storage between the two layers. The deviation is found more pronounced when Omega is small and Kappa is large. It was also found that, as the distance between the active and observation wells increases, the deviation of the observation well response from the equivalent single-layer system response decreases. Vertical permeability has considerable effect on the observation well response when the contrast in transmissibility and storage between the layers is large.