Flow Behavior and Friction Characteristics of Fluid Flow in Coiled Tubing

The coiled tubing (CT) has many applications in the petroleum industry, which include drilling (CT drilling), cementing, wellbore cleanout, acidizing, and hydraulic fracturing. In contrast, the excessive friction pressure loss, due to the relatively small tubing diameter and tubing curvature (which is believed to cause secondary flow) of CT, often limits the maximum obtainable fluid injection rates. Therefore it is of practical importance to investigate the flow regularity and friction properties in CT. Professor Shah and his research team at the Well Construction Technology Center of the University of Oklahoma have conducted numerous theoretical and experimental studies regarding CT and have reported great achievements. This chapter primarily introduces the flow analysis of fluids in the helical segment of CT and friction calculations for Newtonian and non-Newtonian fluid flows.