The effect of axial loading on drill string deformation

Abstract

A practical method for calculating the axial load of a string through the load on a hook is presented and the flotation capacity of elements for different well trajectories is provided. It was found that the traditional simplified method for calculating the buoyancy factor, which is used to calculate the axial load on a string and axial tension, can only be used in vertical wells with a freely suspended pipe string, since in this state buoyancy acts only on the lower part of the string. If the string is constrained by downhole tools such as a packer or an anchor, buoyancy cannot be considered a simple weight loss. In directional wells, buoyancy changes the axial load of the string and causes shear stresses in the cross section of the string. When calculating the effect of fluid on the string, it is necessary to take into account the sequence of operations and stresses from wellhead and downhole tools.