DRILLING HEAD AND METHOD Russian patent published in 1997 - IPC

FIELD: drilling of prospecting holes and production of hydrocarbons. SUBSTANCE: drilling head has calibrating part with supporting zone which is located adjacently to cutting area and is made with smooth wear-resistant surface. Rock crushing members on calibrating surface are arranged at variable incline angle for creating resulting force directed towards supporting zone by specific load which is less than rock crushing strength. Smooth wear-resistant surface can be provided with diamonds. Body is of mass which is distributed nonuniformly. Center of gravity of body mass is displaced towards smooth wear-resistant surface of calibrating part. Rock crushing members can be made of pressed polycrystal diamond. Rock crushing members of end part of drilling head can be located at different angles with creation of resulting force directed radially towards supporting surface with specific load which is less than rock crushing strength. In drilling bore-hole, additionally applied to drilling head is radial force directed towards supporting zone which is located at resulting point of vectors of summed forces created by rock crushing members and axially directed thrust. EFFECT: high efficiency. 6 cl, 24 dwg