Study on Timing Determination and Parameter Optimization for Switching to Pumping in Shale Oil Fractured Horizontal Wells Based on Integration of Fracturing and Production

Shale oil fractured horizontal wells can maintain 3–5 years of natural flow production relying on fracturing stimulation and original formation pressure. As reservoir energy depletes, oil production declines to a relatively low level and recovery efficiency deteriorates. The production method needs to be switched from natural flow to beam pumping to reduce bottomhole pressure, increase production differential pressure, and improve oil production. The tNavigator numerical simulation software was used to perform integrated fracturing-production history matching for the target well. Based on this, comprehensively considering the influence of stress sensitivity and the constraints of economic limit production rate, the judgment conditions for proper pumping conversion timing were proposed, and key parameters after conversion including reasonable bottomhole pressure, pumping speed and pump setting depth were optimized. The results show that after conversion, further reduction of formation pressure will intensify the stress sensitivity effect, so the conversion timing needs to be in the period with relatively low stress sensitivity influence; the bottomhole pressure after conversion should not be too low, requiring consideration of the optimal comprehensive effect between stress sensitivity-induced production loss and increased differential pressure-induced production gain; the production rate should adopt a speed-limiting approach to achieve both production stabilization and enhancement. The determination of shale oil well conversion timing and optimization of proper conversion parameters provide scientific basis for field operation analysis.