WELLHEAD DEVICE FOR RELEASE OF PIPE CASING FROM WELL Russian patent published in 2009 - IPC E21B31/00 

FIELD: oil and gas production.

SUBSTANCE: invention is related to oil and gas industry, in particular to wellhead devices for release of emergency pipe casing caught in well. Device includes damper installed between lift and generator of vertical pulses connected to pipe casing. Damper comprises vertical tight cylinder with piston, internal cavity of which is filled with gas. Generator of vertical pulses is on top connected to damper, and at the bottom - to pipe casing. Generator comprises a tubular body, additional cylinder, annular piston, spring, stop, weight. Annular piston is tightly inserted into an additional cylinder and interacts at the bottom to annular weight that is spring-loaded upwards from stop. Weight is made with the possibility of reciprocal motion along tubular body and interaction at the bottom as it moves upwards to additional cylinder. Above-piston cavity of additional cylinder is made with the possibility of communication with a pulse pump.

EFFECT: simplified design, reduced manufacturing cost and metal intensity.

1 dwg