PROCEDURE FOR PUMPING LIFT GAS INTO PRODUCTION FLOW STRING OF OIL WELL AND DEVICE APPLIED THEREON FOR CONTROL OF LIFT GAS YIELD Russian patent published in 2009 - IPC E21B43/12 

FIELD: oil and gas production.

SUBSTANCE: group of inventions refers to procedure of pumping lift gas into production flow string of oil well via one or several devices for control of yield of lift gas and to facility applied thereon for control of lift gas yield. The essence of the invention is as follows: the facility consists of a tubular case of a valve with a flow passage connected with one end to pressure pipeline of lift gas, while with another end to internal space of production string; further the facility consists of a rotation body of a flap valve connected to the body of the valve and installed in the flow passage so that when the body of the valve turns into an open position it is essentially oriented parallel to the flow passage. When the body of the valve rotates into a closed position it orients perpendicularly to the flow passage and is pressed to a circular saddle of the valve thus shutting off lift gas pass via the flow passage. Also there is a protective bushing designed to slide in the flow passage between the first position, wherein the bushing passes through the circular saddle of the valve during rotation of the valve body in the open position protecting the valve saddle and valve body from wear under flow of lift gas or other fluid, and the second position wherein the bushing passes through a part of the flow passage before the valve body during rotation of the valve body in the closed position. There is a flow limiter forming a part of the protective bushing of the valve; dimension of the limiter produces different pressure with lift gas flowing through it; difference in pressure actuates the bushing to move into the first position. Also the bushing is characterised with a tapered narrowing part. External diametre of the bushing gradually diminishes in a successive direction of the bushing; the first flexible sealing ring is installed in the case before the saddle of the valve, therefore external surface of the narrowing part of the saddle is pressed to internal surface of the first sealing ring when the bushing is in its first position and in such way there is ensured an impenetrable for fluid sealing in circular space between the narrowing part of the bushing and the tubular body of the valve; as a result, in the second position of the bushing, the first sealing ring just not tightly contacts the narrowing part of the bushing.

EFFECT: facilitating efficiency of procedure and reliability of device operation.

10 cl, 2 dwg