Three-dimensional finite element simulation and parametric study for horizontal well hydraulic fracture

Abstract

Estimation or determination of fracture geometry has been one of the most difficult technical challenges in hydraulic fracturing treatment. A three-dimensional non-linear fluid–solid coupling finite element model was established based on the finite element software ABAQUS. The staged fracturing process of a horizontal well in Daqing Oilfield, China was simulated with the model, in which perforation, wellbore, cement casing, one pay zone, two barriers, micro-annulus fracture and transverse fracture are included. The field data of Daqing Oilfield were used in numerical computation. Micro-annulus fracture and transverse fracture generate simultaneously and a typical T-shaped fracture occurs at the early stage of treatment history, then the micro-annulus disappears and only the transverse fracture remains and propagates. The pore pressure distribution in the formation and the fracture configuration during the treatment history are obtained. The evolution of bottomhole pressure as the direct output of simulation is well coincident with the corresponding data from the field measurements. The validation of the model is approved. The effects of several parameters on fracture characteristic are studied with the model. The parameters include in-situ stress contrast, modulus contrast, tensile strength contrast and viscosity of fracturing fluid.