PREVENTING DEVICE Russian patent published in 2004 - IPC

FIELD: oil and gas extractive industry.

SUBSTANCE: device has body with screw-thread die sets placed in it symmetrically perpendicularly to axis of vertical channel of device, said screw-thread dies being of two dimension types with elastic compactors. Also included is control drive for each of them, which includes drive rod having threaded connection to a nut. Screw-thread dies of two dimension types are combined in screw-thread die block and placed into body of screw-thread die block having radial compactor. Screw-thread dies of two dimension types are made in contact to each other by side and horizontal surfaces of elastic compactors. In screw-thread die blocks upper screw-thread die is mounted in fixed manner in the body of screw-thread die block. Drive rod of upper screw-thread die is made hollow and connected to body of screw-thread die block with possible rotation around it. Inside drive hollow rod a drive rod for lower screw-thread die is placed, connected to it with possible rotation around it and around drive hollow rod. Common rotation axis for drive rods is placed perpendicularly to axis of vertical channel of device and may by displaced vertically for a value within limits from zero to half of diameter of recess for body of screw-thread die block.

EFFECT: reliable pressurization of compacted pipes during drilling process and wells maintenance and simplified maintenance, decreased height of device, its metal cost and lesser time needed for closing device.

3 cl, 3 dwg