Optimization of Operational Parameters for Offshore Low-Permeability Fractured Horizontal Wells Based on Fracture Propagation and Productivity Analysis

With the continued decline in recoverable reserves of offshore medium to high permeability reservoirs, increasing attention has been directed toward low permeability reservoirs with permeability below 10 mD. To enhance recovery efficiency in these formations, multi stage hydraulic fracturing has been applied. However, significant flow imbalances among clusters within individual stages have adversely affected well performance. To evaluate the influence of multi cluster fracture geometry on horizontal well productivity, a horizontal well fracturing model was constructed using the FrSmart integrated geomechanical simulation platform. The Displacement Discontinuity Method (DDM) was used to analyze two key parameters, namely cluster spacing and the number of clusters per stage. An optimization study was then carried out using fracture uniformity coefficient and productivity index as evaluation criteria to determine the optimal fracturing parameter combination for offshore low permeability reservoirs. The results indicate that increasing the cluster count leads to greater disparity in fluid intake and fracture length. Cluster spacing strongly affects the uniformity of fracture propagation, and field observations confirm that optimized spacing promotes more uniform fracture growth. Based on the evaluation of fracture uniformity, propped fracture characteristics and productivity under various stage cluster configurations and pumping rates, the optimal parameters were identified as three clusters per stage, stage spacing of 100 m and cluster spacing of 30 m. The recommended operational conditions include a fracturing fluid with a viscosity of 30 mPa·s and a pumping rate of 8 m³/min. These optimized parameters have been successfully applied in offshore low permeability wells and have contributed to improved recovery performance.