Dynamic fracture propagation model for oriented perforation steering fracturing in low permeability reservoir based on microelement method

Oriented perforation steering fracturing technology with the purpose of enlarging fracture extension scale and increasing reservoir reconstruction volume is a common method for stimulating and reforming low permeability oil and gas reservoirs. Accurate prediction of the fracture deflection trajectory is the key to successful implementation of this technology. Based on the relevant theories of elastic fracture mechanics and the microelement method, a prediction model for the fracture deflection trajectory of steering fracturing is established by comprehensively considering the influences of horizontal in situ stress difference, perforation parameters, injection parameters and formation mechanics parameters. The model completes the cyclic iteration calculation between the minor increment and the propagation direction angle of the crack tip using the calculation program compiled by Visual Basic and realizes the simulation of the dynamic propagation of steering fractures. Taking the tight sandstone reservoir of the Shihezi Formation in Linxing block as an example, the differences between the hydraulic fracture trajectory calculated by this model and the extended finite element model and the micro-seismic monitoring values in the fracturing field were compared, and the influence of various factors on the deflection distance of the hydraulic fracture trajectory were studied. The results show that, compared with the XFEM model, the hydraulic fracture trajectory simulated by this model has better matching with the micro-seismic monitoring results. The deflection distance decreases negatively logarithmically with increasing horizontal in situ stress difference and increases linearly with increasing fracturing fluid displacement and viscosity. The larger the perforated angle, the longer the deflection distance, and the length of perforation has little effect on the deflection distance. The model and conclusions are significant to further understand oriented perforation steering fracturing. •Based on microelement method, the mathematical model of dynamic fracture propagation for steering fracturing is established.•The iteration calculation program of the model is developed by Visual Basic.•The accuracy of the model prediction results is verified by comparison with the field fracturing results.•The influence of various factors on the deflection distance is studied.