CORE SAMPLING TOOL Russian patent published in 2008 - IPC E21B25/00 

FIELD: oil and gas well drilling, particularly devices for core taking and delivery to ground surface.

SUBSTANCE: core sampling tool comprises body consisted of at least two tubular modules. Each module is threadedly connected with centrators. Number of centrators exceeds number of tubular modules by one. Tool also comprises upper sub, lower sub to be connected to drilling head, core-receiver arranged inside body. Core-receiver is composed of at least two tubular sections. Each tubular section is threadedly connected to core-receiving couplings. Core-receiver comprises adjustable hanging means made as hollow threaded tubular member and arranged in upper part thereof. Core-receiver also has valve seat and ball, as well as device for core separation from face installed in lower core-receiver part. Said core separation device includes collet and lever corers arranged in case, which is connected to lower part of core-receiver. Tool comprises rotary support arranged in upper part of core-receiver, which is hermetically isolated from tubular sections of core-receiver and body and is provided with resilient axial damping means. Upper sub may be connected with drilling string or to multiple-thread screw gerotor motor spindle. Valve seat and ball are arranged between adjustable hanging means and rotary support. Adjustable hanging means, rotary support and core separation device are made as composite modules connected with each other.

EFFECT: increased manufacturability, reliability and service life along with improved core taking factor and possibility of core property keeping.

6 cl, 4 dwg