Friction Pressures of Newtonian and Non-Newtonian Fluids in Straight and Reeled Coiled Tubing

摘要

As coiled tubing is presently utilized for a multitude ofrnprojects in the field, the necessity of estimating the frictionrnpressure of the working fluids in the reeled portion of therncoiled tubing string becomes extremely important. Pastrnauthors have shown the significant difference in frictionrnpressure between straightened and reeled coiled tubing.rnThis work discusses the experimental investigation of fiverndifferent polymeric solutions and one drilling mud in threerndifferent coiled tubing sizes. The analysis of the frictionalrnpressure loss data includes the effect of fluid rheology, coiledrntubing curvature, and tubing diameter.rnThe intent of the analysis is to arrive at a correlationrndescribing frictional pressure loss behavior of polymerrnsolutions and drilling muds in reeled as well as straightenedrntubing.rnThe experimental setup includes 3000 ft of 2 3/8 in. reeledrntubing, 5000 ft of 1 1/2 in. reeled tubing, and 1500 ft of 1 in.rnReeled tubing. Straightened sections of tubing are also utilizedrnin the setup for comparison and modelling of data.rnThe experimental results are compared with correlationsrndeveloped by earlier investigators including Mashelkar,rnMcCann, Ito, and Shah. The analysis of the data led to therndevelopment of a new model for polymer solutions and arnmodel for drilling muds. The model for polymer solutions isrnrecommended for power law type, pseudoplastic fluids with arnpower law index less than one, while the model developed forrndrilling mud was developed for only one concentration ofrnmud. However, the drilling mud correlation suggests the formrnthat other concentrations of drilling mud may follow.