Numerical Simulation Analysis on the Influence of Wall Inflow on Main Stream in Perforation Completion

Abstract

A considerable number of experimental work on the influence of flux ration on wellbore pressure drop in perforated completed horizontal wells has been published by many scholars, but the effects of the wall inflow on the main stream have not been studied systematically. The RNG k-ε turbulence model in computational fluid dynamics software FLUENT was used to simulate the influence of wall inflow on the main stream in perforation completion. Under the condition of different injection ratio (0.1%–80%) the pressure and variation regularity along the wellbore and perforation section with 90° phase angle spiral perforation format is studied. The influence of different wall injection ratio and different viscosity of crude oil on wall total pressure drop is also analyzed. The results of the study show that: Under different injection ratio, the total pressure drop of wellbore increases with the increase of wall injection ratio. The speed of the main stream is less than that of the outlet and the inlet velocity decreases with the increase of wall injection ratio and the exit velocity increases gradually. Moreover, the outlet streamline is more and more densely, and the influx is significantly affected. The inflow velocity increases with the increase of injection ratio, and the wall pressure drop gradually increases. Under the same injection ratio, the pressure drop of high viscosity crude oil well is higher than that of low viscosity crude oil. When the viscosity is 132 cp, the pressure drop in the wellbore section is about 2 times the viscosity of 19 cp crude oil. The flow chart of high viscosity crude is lower than that of viscous crude oil, and the influx is significantly affected by inflow. It can be seen from the pressure cloud map of well bore and perforation section, velocity cloud map and streamline map (whole, entrance and exit) that the pressure drop in the wellbore changes obviously corresponding to the injection ratio of 5%, the main flow velocity is obviously changed corresponding to the injection ratio of 25%. The effects of perforation parameters and injection ratio on the total pressure drop of the wellbore wall are studied in this paper, which provides a scientific basis for the establishment of a well bore pressure drop model in perforated well completion.