THREE-DIMENSIONAL FINITE ELEMENT NUMERICAL SIMULATION OF HORIZONTAL WELL HYDRAULIC FRACTURING

Multiple transverse fractures could be generated in the process of horizontal well hydraulic fracturing, which may achieve higher productivity than vertical well hydraulic fracturing, so more and more horizontal well hydraulic fracturings were performed in recent years. In this paper, fluid-solid coupling elements were used to describe the behavior of rock fluid-solid coupling, and pore pressure cohesive elements were employed to simulate the process of fracture initiation and propagation in oil and barrier layers, thus perforations were connected to micro-annulus and transverse fractures, making it possible that micro-annulus fracture and transverse fracture propagate simultaneously. A 3D non-linear fluid-solid coupling finite element model for a horizontal well in Daqing Oilfield was established with the ABAQUS platform. Numerical simulations were performed for a staged fracturing process of the horizontal well. The parameters of formation and physical properties in simulations were adopted from Daqing Oilfield. Fracture geometry, pore pressure distribution, stress and strain distribution in oil and barrier layers were obtained. Fracture height was much smaller than fracture length. The fracture geometry obtained from numerical simulation was in good coincidence with that obtained from field measurement. The pressure history evolution at the bottomhole obtained from numerical simulation was consistent with field measurement results. The correctness and rationality of the simulation model were verified.