Study on Optimization Design of Hydraulic Fracturing Construction Parameters for Vertical Wells in Low-Permeability Reservoirs

The construction parameters of hydraulic fracturing have a direct impact on the propagation morphology of fractures and the post-fracturing productivity of single well. Optimizing the construction parameters can effectively improve reservoir stimulation effect and increase the recovery rate of single well. The W Block of Xinjiang Oilfield, characterized by medium porosity and low permeability mudstone sandstone, must rely on hydraulic fracturing technology to achieve economic development. Using Petrel-Kinetix fracturing numerical simulation software, a numerical simulation model of vertical well fracturing considering fluid-solid coupling was established, with J10 well in this block as the research object. The influence mechanism of the pad fluid ratio, fluid displacement, and sand ratio on the propagation morphology of fractures and reservoir stimulation volume was studied using this model. The optimization design of hydraulic fracturing schemes was carried out by evaluating the single well productivity under different hydraulic fracturing construction parameters. The research results indicate that the pad fluid ratio and fluid displacement have a significant impact on the length of hydraulic fractures in this block, while fracture width is mainly controlled by sand ratio. The shorter the fracture length required to achieve the same oil production, the higher the permeability and the thinner the reservoir thickness. As the pad fluid ratio, fluid displacement, and sand ratio increase, the reservoir stimulation volume and the cumulative oil production of single well will increase, but the growth rate will gradually slow down.