Multi-Stage Deflective Fracturing Technology for Low Permeability Reservoir

Problems such as small sweeping volume, short longevity and poor fracturing stimulation effects are common when conventional fracturing technology is adopted in low permeability reservoirs. In order to improve the production of low-permeability oil and gas fields, a high-performance temporary bridging agent with high solubility, fast dissolution rate, low residue content and low damage to permeability was developed with deployment using an innovative multi-stage deflective fracturing technology. These were developed based on geological characteristics of the reservoir and the initiation mechanism of multi-stage deflective fracturing. When the formation is fractured, a temporary bridging agent is added in the frac fluid in real time to form instantaneous temporary bridging at the opening of fractures. These result increased net pressure within fractures, and generate microfractures and branch fractures, thus forming complex network fractures and achieving the goal of volumetric stimulation. After the application of multi-stage deflective fracturing technology in Block X of the Xinjiang Oilfield, oil production dramatically increased, and daily oil increment per well is 2.0 times that of wells with conventional fracturing technique. In addition, this method results in a longer stable production period, and the longevity is 50% higher than that with conventional fracturing. The application of multi-stage deflective fracturing technology can solve the problem of reservoir stimulation in low permeability conglomerate reservoirs and provided a new technical mean for achieving stable production in the late production period of low permeability conglomerate reservoirs.