METHOD FOR SIMULTANEOUS DISPLACEMENT OF HEAD VALVES OF PRODUCTION TREE UNDER PRESSURE Russian patent published in 2010 - IPC E21B33/03 

FIELD: oil and gas production.

SUBSTANCE: wings and production tree valves are closed. Four supports are mounted on lower flange of tube head spool, and on two of which two rotary rolls of rope tooling. Case of sealing device is mounted on upper flange of buffer gate valve. Assembly is assembled as made of composite stands, mounting and packer stems, three cross beams. Using weight-lifting equipment connected to upper cross beam, assembly is driven to production tree, and composite stands are joined to two other supports. Packer element is lowered into shaft of production tree on mounting stem below shaft gate valves, and shaft is sealed by rotation of packer stem. Nuts of lower flange of replaced gate valve are unscrewed, and by rotating nuts in composite stands, body of sealing device is lifted above production tree. Fixtures are released on four supports, and sealing device is removed from well together with replaced valves. After replacement of valves for the new ones, they are assembled on pipe head, assembly is fixed in attachable brackets, and packer element is lifted, afterwards, sealing device is dismantled.

EFFECT: invention provides for the possibility to simultaneously replace shaft valves of production tree under pressure, without well killing.

1 dwg