The Refined-Control Vertical Fracturing Technology for Thin and Low Permeability Interbeded Reservoir

Abstract

This paper presents a technology that can control fracturing properly in the thin layers in peripheral Daqing oil fields. The layers are thin and numerous, and the lithology is very complex, so the conventional frac or limited entry fracturing has been serious inadaptability. For an example, only 47% of the oil layers produce in a single well, Lots of thin layers in peripheral oil field couldn't be fractured, and reservoir could not be developed fully,, so the effects t of fracturing is poor. Refined-controlled fracturing technique takes into account reservoir nature, lithologic character and the distribution of in-situ stress. In this case, the organic integration of detailed geological research and control technique has been achieved. 308 wells have been applied and tested the technology. The technology break through the limits that the fracturing layers must be more than 4m and stratified according to thickness of the barrier and crustal stress in the past. The effect of perforation parameters to the fracture's initiation direction has been determined by three-dimensional elastic-plastic finite element techniques. Based on the fracture mechanics, the model of fracture extension has been built, and simulated the perforation and its impacts, the contrast of horizontal stress on the deflection of fracture. Based on theoretical study, the perforation design of fracturing wells has been developed.