Research on the Prediction Method of Gravel Packing Pressure for the Bypass Path of Horizontal Wells

Bypass path gravel packing technology for horizontal wells is an innovative solution for sand control operations under complex well conditions. It exhibits significant advantages in scenarios such as low-cementation formations, low fracture pressure, high fluid loss, small wellbores, and extended horizontal sections, and is particularly suitable for sand control in deepwater shallow oil and gas wells as well as deepwater natural gas hydrate wells. However, this technology faces challenges including unclear packing mechanisms, single and low-accuracy packing pressure prediction methods, and lag in the dynamic adjustment of construction parameters. This study systematically analyzes the packing mechanisms under both open and closed states of the bypass path: when the path is closed, the packing process follows the classical equilibrium dune principle, which is divided into the α-wave forward packing stage and β-wave reverse packing stage; when the path is open, the fluid flow pattern transitions to complex multiphase flow, and the sand particle settlement law changes significantly. Based on drilling hydrodynamics and cyclic friction theory, a multi-stage pressure prediction model for the heel of horizontal wells was constructed, and its applicability was verified through engineering cases. Results show that the model can accurately predict the pressure change trend at the heel of the horizontal section and the pressure values at key time nodes, with an average error of less than 6% between the predicted values and field-measured data. It provides reliable theoretical support for optimizing construction parameters and ensuring operational safety. The model can guide the implementation of bypass path gravel packing technology in horizontal wells and reduce construction risks.