Research and application of rock fracturing pressure prediction method for deep oil reservoirs.

The combination of extreme formation pressure, significant burial depth, and dense lithology in deep and ultra-deep reservoirs results in abnormal fracturing pressure behavior. This phenomenon elevates operational pressures during fracturing acidizing treatments while amplifying associated engineering risks. Precise prediction of both reservoir fracturing pressure and pump injection pressure has become imperative under current technological constraints to ensure operational safety and successful reservoir stimulation. This study establishes a comprehensive fracturing pressure prediction framework through: Developing rock fracturing pressure models for open-hole and perforated completions based on near-wellbore stress distribution characteristics. Investigating fracture initiation mechanisms and corresponding computational models for perforation-altered stress fields. Deriving damage-adapted calculation models that account for stress variations in both completion types under formation impairment conditions. Numerical simulations demonstrate critical findings revealed that perforated completions reduce reservoir fracturing pressure by 10-15% compared to open-hole configurations, proving effective for pressure management. Formation damage induces stress redistribution, increasing fracturing pressure by 8-12%-a crucial factor for treatment design optimization. Maximum pressure reduction (18-22%) occurs when perforation orientation aligns within ± 40° of the maximum horizontal stress direction, beyond which fracture deviation triggers abrupt pressure escalation. Perforation density shows linear correlation with pressure reduction (3-5% decrease per 2 shots/m increase), while perforation dimensions exhibit limited impact (< 1% variation). The developed multi-completion prediction methodology provides dual engineering benefits: It enhances operational safety for hydraulic fracturing in deep reservoirs through reliable pressure forecasting, while serving as a strategic optimization tool for completion design-particularly in maximizing hydrocarbon recovery from challenging deep formations. This approach establishes a critical technical foundation for economically viable development of deep petroleum resources.