CALIBRATOR-CENTRALISER Russian patent published in 2012 - IPC E21B10/26 E21B17/10 

FIELD: mining.

SUBSTANCE: calibrator-centraliser includes housing and blades with cylindrical and inclined sections, which are reinforced with rock-destructing elements (RDE). Transition zone between lower section inclined at an angle of 15°-30° degrees to housing axis and cylindrical section of each blade is reinforced with three different groups of cylindrical diamond-containing inserts. The first group of inserts represents RDE of cutting-splitting action; the second group represents RDE of cutting-crushing action and the third group represents RDE of stabilising action. RDE of the first group are located in upper part of lower inclined section of blades and made on the side of diamond layer with a chamfer at an angle of 10°-15° to cylinder axis. Cylinder axis is located in horizontal plane and forms together with the plane tangent to cylindrical blade surface the angle of 15°-30°; inclined chamfer surface faces the well wall, and cutting edge of diamond-containing layer in the form of a line is parallel to housing axis. The second group of RDE is located on lower section at front edge of cylindrical blade section in rotation direction of calibrator-centraliser. Axis of these inserts is located perpendicular to housing axis, and working head of inserts is formed with natural or artificial diamonds fixed in wear-resistant matrix. The third group of RDE is located in rotation direction behind inserts of the second group. Axis of inserts is also located perpendicular to housing axis, and they are made in the form of two-layer element with diamond working disc.

EFFECT: higher operating efficiency of calibrator-centraliser during drilling process; avoiding the hanging of tool on it; increasing mechanical drilling speed and enlarging operating period.

3 cl, 6 dwg