EGR stimulation research project - direct observation of hydraulic and dynamic fracturing

Conducting controlled fracturing experiments which are subsequently available for direct observation has been shown to be feasible and is producing significant new observations. Hydraulic fractures have been shown to be relatively unaffected by interfaces between formations with different properties. Specifically, the upwards growth of a fracture was not contained by an overlying formation with significantly higher modulus and rectangular, bounded fracture geometries should not be assumed. The High Energy Gas Frac has been shown to be a viable technique for creating multiple, randomly oriented fractures in a borehole. This field test has demonstrated that a propellant can be suitably designed to provide (1) a large enough loading rate to initiate multiple fractures, (2) high enough pressures to extend fractures radially, but not so high as to exceed the flow stress of the rock, and (3) sufficient gas generation to allow most of the fractures to be pressurized and propagated further.