Shock absorbing apparatus and drill string using such apparatus

Abstract

Abstract A shock absorbing apparatus for connection in a drilling string and capable of transmitting the axial drilling work loads and the torsional forces required for rotating a drill bit at the bottom of the drill string include an elongated housing (12) and a mandrel (14) extending longitudinally within the hous­ ing. The housing interior and the mandrel have mutually co-operating formations (26, 24) thereon for transmitting the axial and torsional forces. The mutually co-operating forma­ tions have substantial clearance spaces (28, 30) therebetween such that the mandrel has a substantial degree of axial and torsional freedom relative to said housing. A matrix of resi­ liently deformable material (32) is disposed in the clearance spaces between the mutually co-operating formations so that under the influence of shock loadings on the drill string, the matrix of material deforms and flows to take up and reduce the shocks and vibrations transmitted between the mandrel and the housing.

Inventors

• 👤 Bruno Walter

Bibliographic Details