Fluid-Flow Phenomena in CT Using CFD

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractCoiled tubing (CT) is widely used in well intervention as a practical and cost-effective means of servicing wells. Over the years, the actual flow through CT has been a point of discussion and theory. Testing has been conducted to promote a better understanding of what happens inside the CT. In recent years, the use of computational fluid dynamics (CFD) software has provided greater insight into actual CT flow patterns, including fluid-flow velocity profiles and secondary flow regimes. These flow patterns can be studied in a straight pipe or curved (CT) condition with variable flow rates and variable fluids. CFD could help us understand the phenomenon of erosion, including particle path and migration through the tubing. It might also lead to a greater understanding and efficient design of friction pressure gradients. After CFD is proven and established, an alternative to full-scale testing or other predictive methods may be possible.This paper discusses the flow phenomenon of CT using CFD, particularly over the tubing guide. This is an area of concern because the tubing configuration changes from straight to bent to straight again. Details of fluid flow for both the straight and curved sections have been examined to evaluate flow-velocity profiles and flow patterns. Fluids investigated have included water, gel, and slurry.

Dynamic Analysis of Bottom Hole Assembly With External Vibrating Force Excitation

“…Rosine et al [21] investigated Coiled Tubing with CFD. CT is a practical and cost-P-ffed.ive means wlwn bei ng operated in well intervP-ntion in servicing wells.…”

“…CT is a practical and cost-P-ffed.ive means wlwn bei ng operated in well intervP-ntion in servicing wells. Based on the fact that the actual fl ow t hrough CT has still not been revealed clearly, Computa tional Fluid Dynamics is becoming widely used in this investigation [21] . The CFD software employed was FLUENT.…”

“…As a result , execut ing a full-scale CFD model can cost significantly less than full-scale testing. Also, the research investigated t he fluid flow in both straight and curve sections and the detailed results were t hen used to evaluate the ftow-velocitv profile and the flow patterns [21].…”

“…principles of rn a · , moment um , and energy ·onservation. CFD software is able to simulate 3-D fl ows and deals with moving boumlary conditions caused by changing geometry [21]. B sides, using software can help create some experimental condi tions which a re not easy to realize in real experiments.…”

Particle Distribution and Erosion During the Flow of Newtonian and Non-Newtonian Slurries in Straight and Coiled Pipes

“…The erosion rate is proportional to the balance of the forces acting on the particle resulting from particle-particle interaction and particle-fluid interactions as well as the force arising from the immersed weight of the particles. Simulation studies presented by Rosine, Bailey and Blanco (2005) and Bailey, Blanco and Rosine (2006) have investigated the flow of guar fluid slurries through coiled tubing and have reported the sand distribution at various flow cross sections at the tubing reel and over the gooseneck, a section thought to be most susceptible to erosion. These studies have dealt with a single fluid and do not investigate the variation in particle distribution with the change in fluid type and viscosity.…”