CORE SAMPLER Russian patent published in 2009 - IPC E21B25/00 

FIELD: oil and gas production.

SUBSTANCE: invention refers to drilling tool, particularly to facilities for drilling with core sampling. The core sampler consists of a case with an upper drilling tool substitute and a bore bit in a lower part, of a core receiver made in form of a pipe and equipped with a rotation support in the upper part containing a case with bearings and axis; the core receiver is also equipped with a regulated suspension bracket containing a stop and nut connected to the case of the sampler; further, the sampler consists of an upper sealing unit, containing a plug shutting off a channel made in the axis of the rotation support, of a unit for separating core from the bottom including a sleeve tied by means of a bayonet connection with a lower part of the core receiver and of movable lever and collet core catchers installed in the sleeve with a bushing between them, of an lower sealing unit in form of a breakable diaphragm installed in the cartridge connected with the lower part of the sleeve and movably interacting with a boring made in the cone bit. The cavity of the core receiver is filled with insulating liquid on non-water base with anti-friction properties and with density less, than density of drilling agent. Also the core receiver is additionally equipped with overflow valves, the upper one of which is made in form of a spring loaded ball valve, installed in a through radial opening cut in the axis of the rotation support; the latter is designed to perform lengthwise travels in a threaded bushing interacting with the nut and the stop of the regulated suspension bracket, while the lower overflow valve is assembled in the sleeve of the unit for separating core from the bottom and contains a ring out of elastic material installed in a groove cut on external surface of the bushing and hydraulically connected with the cavity of the sleeve with radial through openings made in diametre plane in the wall of the bushing. Between the upper end of the lever core catcher and the lower end of the core receiver in the sleeve in the initial position there is made a gap, the dimension of which is not less, than the distance along lengthwise axis of the core receiver between the through radial openings and the upper edge of the boring.

EFFECT: increased reliability of core sampler operation and increased core recovery.

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