Numerical Modeling of Hydraulic Fracture and Permeable Crack Interaction Nearby a Void
A. V. Azarov, V. V. Skazka, S. V. Serdyukov
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Rock mass, hydraulic fracturing, void, stress state, permeable crack, mathematical modeling, finite element method, cohesive fracture model, cohesive layer, hydraulic fracture-crack interaction
Abstract
The article analyzes interaction of a hydraulic fracture and a permeable crack nearby a void in a uniform medium under triaxial compression. 2D modeling used the finite element method. Possible paths of the created fracture are set as cohesive layers composed of elements which can deform and fail depending on an applied stress. A fluid flow is modeled by additional points with crossflow of fluid from the created fracture into the permeable crack when they intersect. The numerical studies are presented for the nature of the hydraulic fracture-permeable crack interaction depending on the: distance between their interaction point and the void; stress state; strength and internal friction factor of the medium; fluid viscosity. On the basis of the obtained results, for the creation of an antiseepage screen, it is recommended to perform hydraulic fracturing in the vicinity a void at a distance equal to the void radius.
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