| The propagation of a hydraulically induced fracture, which is initiated from a deviated wellbore, was studied in this dissertation. The three dimensional stress distribution around the wellbore was derived by applying the theory of elasticity. The equation of the fluid pressure required for initiating a fracture as well as the equation of the location and orientation of the induced fracture plane were derived by using this stress distribution together with a designated tensile failure stress for the rock medium. By applying the finite element method, it was demonstrated that the subsequent fracture plane from a deviated wellbore would turn and twist aligning itself to the preferred direction during the early stage of propagation.;The object of this study is to provide engineers with a theoretical guide to the fracture design of a deviated well. The effect of casing on the behavior of a hydraulically induced fracture and the perforation spacing required for forming a major fracture along the wellbore were also studied in this dissertation. Three computer programs were developed for carrying out the required calculations. The results from this study have demonstrated that the hydraulic fracture initiated at the tension zone of the wellbore would have a larger turning radius and a wider opening width than would fractures initiated at other locations. |
