Physical Modeling of Hydraulic Fracturing in Cross Boreholes in Nonuniform Stress Field

The article describes the lab-scale tests of hydraulic fracturing in the nonuniform stress field. Fractures were created in a system of two and three cross holes made in artificial cubic blocks with the edges 420 mm long. The stress raiser generated at the intersection of the holes facilitates fracturing in the neighborhood. In the tests the maximum compression was applied to a sample in perpendicular to the plane containing the axes of the holes. It is found that in such stress field, the system of three holes stabilizes a fracture in the mentioned plane better than the system of two holes.