Effect of Tool Joints on Passages of Plane Longitudinal and Torsional Waves Along a Drill Pipe

Abstract

The effect of tool joints on the passage of plane longitudinal and torsional waves along a drill pipe was studied. An approximate solution to the governing equations of motion was found, and an idealized tool joint constructed. Calculations were made for the effect of the idealized joint on an example drill string. The results showed that tool joints had negligible effect for exciting frequencies of the same order as common rotary speeds and the drill pipe could be taken as a uniform pipe with negligible error.