Forces on Curved Tubulars Caused By Fluid Flow

Abstract

Summary This paper examines the effects of fluid pressures and flowing fluid momentum on curved tubing, casing, or drillpipe in a wellbore. A general expression for fluid forces on curved tubing is developed. Special cases, such as the "fictitious force" used in tubing buckling analysis, are developed and explained in terms of actual physical behavior. New problems, such as the effect of tubing eccentricity on fluid forces and the effect of external flow on tubing buckling, are identified. Lateral forces developed in curved tubulars caused by fluid pressure can be much higher than expected, with significant impact on friction drag loads and pipe sticking.