Abstract
Coiled Tubing is used increasingly to service highly deviated and horizontal well. A limitation or horizontal displacement occurs because of the frictional forces between the coiled tubing string and borehole while running in coiled tubing. This causes helical buckling and can lead to lockup of the coiled tubing string, thereby limiting reach.
This paper will address the various techniques currently in use and propose new techniques to achieve additional reach. The topics that will be discussed are buoyancy reduction, friction reducers, optimal taper and pipe size of coiled tubing, straightening coiled tubing, downhole tractor simulation, flowing fluid, and pumpdown.
A tubing forces model has been developed that models these techniques. Results showing additional reach attained will be presented in the form of the surface weight prediction for commercial and conceptual wells.
