METHOD FOR CALCULATING SPIRAL FLOW VELOCITY OF NEWTONIAN FLUID ECCENTRIC ANNULI

摘要

A method for calculating spiral flow velocity of Newtonian fluid eccentric annuli is characterized in that an analytical method is adopted for calculating the spiral flow field of eccentric annuli; the three-dimensional spiral flow is simplified to the two-dimensional flow in the thin layer of annuli through mapping the momentum tensor equation of Newtonian fluid in the three-dimensional Euclidean space into the two-dimensional space of Riemann surface, and finally the analytic solution of spiral flow velocity of Newtonian fluid eccentric annuli, which is concisely expressed, is obtained. The analytic solution of spiral flow velocity of Newtonian fluid eccentric annuli of the invention can be used for predicting and quantizing the problems of cement top between the wide-clearance cement slurry and narrow-clearance cement slurry and slury channeling in the two-phase flow when the oil drilling slurry replaces the cement slurry. The method of the invention has important practical significance in researching the cuttings-carrying flow regulation of annuli of oil well-drilling project, calculating the course flow resistance of wellhead annuli and increasing the calculating accuracy.