Development of a True 3D Hydraulic Fracturing Simulator

摘要

The recent development of horizontal and deviated boreholerndrilling technology in oil and gas wells requires hydraulicrnfracturing simulators which can take the three-dimensionalrnformation of fractures into account. The authors haverndeveloped a fully coupled modeling of fracture opening andrninjected fluid flow for the three-dimensional formation ofrnhydraulically induced fractures. The simulation can deal withrnthe entire process of hydraulic fracturing including the postshut-rnin process. A three-dimensional DisplacementrnDiscontinuity (DD) formulation for an elastic medium is usedrnto model the relationship of fracture aperture and stress aroundrnthe fracture. This formulation allows the simulator to deal withrnthree-dimensional fracture propagation including bending andrntwisting of the fracture.rnFracture propagation based on the linear elastic fracturernmechanics model, non-Newtonian behavior of the fracturernfluid, and proppant transportation are modeled in thernsimulator. Fracturing processes including the post-shut-inrnprocess are calculated so as to satisfy the equilibrium ofrninjected fluid volume, fracture volume and leak-off volume.rnThe numerical fracturing simulator can be used as arnplatform for studying the behavior of complicated hydraulicrnfracturing processes, and as a tool for the optimal design ofrnhydraulic induced fractures.