Research and Practice on Balanced Fracture Initiation Technology for Shale Oil Horizontal Well Hydraulic Fracturing

To address challenges in D Oilfield’s lamellar shale oil development, such as deep burial depth, strong heterogeneity, and uneven competitive initiation and propagation of multi-cluster fractures within a single stage, research was conducted on balanced fracture initiation technology. Heterogeneity evaluation within stages was performed based on calculations of bottomhole mechanical specific energy and minimum horizontal principal stress in horizontal sections, optimizing fracture stage length. A flow rate-perforation number-throttling friction chart was established to optimize the number of perforations per stage and injection rate according to throttling friction requirements. Numerical simulations of fracture propagation under uniform, spindle-shaped, and tapered perforation layouts were carried out to optimize perforation patterns, followed by field trials. Results demonstrate that a stage length of 50–60 m, 10 clusters with 32 perforations per stage, an injection rate of 14–16 m3/min, and spindle-shaped perforation layout significantly improved fracture uniformity (from 0.79 to 0.88). This technology provides critical research insights and technical support for establishing a cost-effective shale oil development demonstration platform in D Oilfield.