Analysis on Stress Concentration Produced by Hanging Holes for Electromagnetic Wave Resistivity Instrument and the Structure Optimization Design

Abstract:

The stress concentration caused by the drill collar hanging holes for the electromagnetic wave resistivity tool is the weakest strength point of the drill collar, which finally influences the service life of drill collar. The structure of the drill collar with electromagnetic wave resistivity instrument is described in this paper, and the schemes of distance between the hanging holes of drill collar and the different angles with the resonant window in the circumferential directions are discussed. The entity models of drill dollar structures are made by three-dimensional modeling software and finite element analysis software module, the finite element calculations are performed under 2 conditions of imposing single torque load and imposing the compound load of pressure and torque to select a kind of reasonable structure, which can be a theoretical basis for optimal design and manufacture of new drill collar next.

Key words:electromagnetic wave resistivity; round hole stress concentration; optimal design; finite element calculation; drill collar