The Numerical Simulation Study of Bottomhole Pulse Fracturing Pressure Enhancement Effect

ABSTRACT: As global oil and gas exploration extends into deep and ultra-deep formations, conventional hydraulic fracturing techniques face challenges such as high operational pressure and energy consumption in deep strata. To address this challenge, this paper proposes an in-situ directional pulse fracturing method. This method generates controllable pressure oscillation waves in the target formation section through an in-well pulse generation device, utilizing the waveguide characteristics of the wellbore-formation system to achieve bottomhole pressure enhancement and improve fracturing effectiveness in deep formations. This study adopts Computational Fluid Dynamics (CFD) methods to construct a three-dimensional transient numerical model that simulates the generation and transmission process of pressure waves within the wellbore. The study investigates the effects of piston inner diameter, piston stroke, pulsation-wellbottom Standoff (PWS), and pressure wave frequency on bottomhole pressure enhancement. The simulation results show that the amplitude of the pressure wave decreases with the increase of the piston inner diameter and increases with the increase of the piston stroke. When the wellbore length is an odd multiple of one-quarter of the pressure wave wavelength, the bottomhole pressure enhancement effect is most significant. This research provides a theoretical basis for optimizing the wellbore length design of the fracturing section and selecting pressure wave frequency, offering a reference for new approaches to in-situ pulse fracturing in deep formations.