STABILIZER Russian patent published in 2002 - IPC

FIELD: deep drilling. SUBSTANCE: invention is related to supporting-centering gears centering lower part of drilling string. Stabilizer includes body with axial washing passage and fastening threads, two blades reinforced by inserts of wear-resistant material. It has variable rigidity while bent with reference to major central axes of its cross-section having shape of ring with segments cut away on opposites sides. EFFECT: qualitative centering of lower part of drilling string and free travel of stabilizer along shaft of corrected hole while drilling tools are sunk or lifted. 1 cl, 2 dwg