The Experimental Investigation of Fracture Propagation Behavior and Fracture Geometry in Hydraulic Fracturing through Oriented Perforations

摘要

Hydraulic fracture propagation behavior and geometry through perforated vertical wellbores are studied by a series of servo-controlled tri-axial large-scale fracturing experiments. The experimental results show that the tortuous fracture can be generated by using oriented perforation fracturing technology. By changing the perforation angle and the horizontal differential stress, it is found that the fracture propagation behavior and fracture reorientation path are obviously influenced by these parameters. The effect of a micro-annulus near the casing on the fracture initiation and its geometry is also discussed; it makes the fracture initiation as from an open hole. The conclusions are significant to further understanding of hydraulic fracturing process.