Experimental Study of Fracture Propagation Mechanisms by Oriented Perforation Technology for SRV Fracturing

Abstract

Due to the growing importance of shale oil and gas resources, more effective techniques to develop unconventional reservoirs are strongly required. In this paper, a new volumetric fracturing measure for unconventional resources based on oriented perforation technology has been introduced. Moreover, this innovative approach was validated through a series of laboratory experiments varying the parameters of physical models, such as perforation azimuth, perforation length and horizontal stress difference. The results showed that the artificial hydraulic fracture formed by using oriented perforation technology was not a satisfactory straight dual-wing fracture, instead, it was a bent dual-wing crack like “S” or “X”, which could significantly increase the stimulated reservoir volume. The perforation azimuth and horizontal stress difference were the primary factors that affected the formation of multi fractures. The reorientation path was extended with the increasing of the oriented perforation azimuth angle, but decreased with the increasing of horizontal stress difference. In addition, increasing the perforation length could greatly decrease the initiation pressure. Therefore, the oriented perforation technology could be as a powerful way to accelerate the exploitation of the unconventional reservoirs.