ONE-CONE DRILL BIT Russian patent published in 2000 - IPC

FIELD: rock-cutting tools. SUBSTANCE: one-cone drill bit is used in construction of oil and gas wells and in drilling of geological exploration wells. One-cone drill bit for drilling well below casing string consists of body with fastening thread and water course, ellipsoid con with rock-cutting members in it. Fixing device is made in the form of spring-loaded pin, collar and water course. In this case, body water course is communicated with water course of fixing device for building up of higher pressure exerted on collar as compared with pressure behind cone, lifting of pin and releasing cone fixation in supply of mud to water courses. With use of the one-cone drill bit, well is constructed at one stage without use of hydraulic expander to reduce work volume and expenditures and to save material and technical means and to reduce cost of drilling by a factor of two as compared with known one-cone drill bit. EFFECT: improved design. 1 dwg