Design and Analysis of a Hydraulic Fracture in the Tar Sand at Northwest Asphalt Ridge, Utah

摘要

Material properties and the in-situ stress field information are used to design and analyze a hydraulic fracture experiment in tar sand. Simplified mathematical models have been used to correlate the measured tilts (uplift gradient) at the surface during fracture treatment to the fracture orientation and geometry. Recommendations are made for post-fracture investigation to ascertain the validity of the analysis and the predictability of fracture orientation. Measurements and analysis suggest that the induced fracture was initiated horizontally but turned to a near vertical plane on propagation. This is considered to be a result of the near hydrostatic stress state in which the induced fracture has no preferred orientation and local inhomogeneities, etc., may change the propagation direction. (ERA citation 06:029959)