In horizontal and extended-reach wells in which long completions are run into highly deviated or lateral zones, large compression loads arise because of running friction. These loads remain locked in the string when the packer or cement sets. Dissipation of friction caused by string vibrations and movements redistributes these friction loads between the wellhead and the packer or the top of the cement. A numerical approach is presented to calculate the redistributed friction load so that an accurate initial tubing load is implemented in the tubular-stress analysis.
Introduction
The long lateral wells in modern shale developments provide new motivation to better understand and model the effect of friction in casing and tubing design. The multiple-barrier approach and modern design techniques compare favorably with previous generations of well construction. Even so, the root-cause failure analysis of individual subsurface components such as tubing, connections, or packers is difficult.
