Low-frequency distributed acoustic sensing (LF-DAS) is one of the promising diagnostic techniques to detect and characterize hydraulic fractures. LF-DAS signals can capture fracture hits and the strain field around the hydraulic fracture. However, the interpretation of field LF-DAS data and the relationship between fluid allocation and production can be challenging due to the complexity of the underground conditions. This study develops a fracture propagation model to simulate the hydraulic fracturing process. The modelling results are analyzed to examine patterns and trends observed in actual field DAS data.
The fracture propagation model, coupled with the flow and geomechanical computations, is implemented in the MATLAB Reservoir Simulation Toolbox (MRST). The flow and geomechanical calculations are discretized by the finite volume and virtual element methods, respectively. The hydraulic fracture is set to propagate along a prescribed path with a specified propagation or activation criterion. The accuracy of our model is validated against the KGD analytical solutions for the leak-off-viscosity and storage-viscosity dominated regimes.
The simulated stress and strain features are consistent with those interpreted from field DAS signals. Several case studies are presented to demonstrate the modelling approach's utility and examine fracture interference, closure, and stress shadowing effects. The modelling work facilitates interpreting field measurement data by investigating characteristics of fracture hits from adjacent wells. The modelling method provides insights into fracture interference and its implications on optimal designs during hydraulic fracturing stimulation.