Spatially Informed Inter-Well Connectivity Logging in Conventional Reservoirs using LF-DAS: A Numerical Study

Low-Frequency Distributed Acoustic Sensing (LF-DAS) has emerged as a valuable tool for downhole in-well and cross-well monitoring. This study numerically investigates the application of LF-DAS strain rate measurements to enable spatially informed interference testing analysis in conventional reservoirs. Using poroelastic simulations, we examine rock's response to water and gas injection in offset wells, capturing the coupled dynamics of fluid flow, mechanical deformation, and poroelastic behavior across the reservoir. Strain rate tensors along the monitoring wells are measured and compared with local pressure derivatives to assess their correlation. The results demonstrate that the temporal evolution of LF strain rate exhibits characteristics similar to pressure derivative plots. By applying a multi-segment interference testing analysis approach, we constructed the LF-DAS strain rate plot for each segment of the monitoring well as a proxy for the zonal pressure derivative plot and successfully produced an inter-well connectivity log along the well. This DAS-assisted well testing approach introduces new opportunities to enhance conventional well testing methods by providing greater spatial clarity and aiding in the identification of local inter-well discontinuities such as unconformities, barriers, and baffles that influence reservoir performance.