Study of permeability coefficient and inflow rate effects on hydraulic fracturing in saturated porous media

Document Type : Research Article

Authors

Faculty of Civil Engineering, K.N.Toosi University of Technology, Tehran, Iran

Abstract

In this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in saturated porous media. The model is derived within the framework of generalized Biot theory. The fracture propagation is governed by a cohesive fracture model. The flow within the fracture zone is modeled considering the lubrication equation. In order to describe the fracture in the saturated porous media, momentum equation and mass balance equation with Darcy law are employed. The standard Galerkin method and Newmark scheme are used for discretization in space and time, respectively. Finally, the effects of permeability and rate of injection on the hydraulic fracture propagation are studied. It is observed that an increase in permeability leads to slower crack propagation. In addition, increasing flow rate leads to a faster crack propagation. When permeability increases by 3.3 times, CMOD and crack length decreases by 43.8% and 20%, ,respectively after 1 second and decreases by 29.4% and 15.9%, respectively after 6 seconds. In addition, when flow rate increases by 2, 3, and 4 times, the crack length increases by 30.5%, 55.9%, and 76.3% after one second.

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