PRODUCTION STRING OR CASING PIPE CONNECTION IN OIL AND GAS WELLS Russian patent published in 2005 - IPC

FIELD: oil industry, particularly to connect casing pipes or production strings.

SUBSTANCE: connection comprises pipes with outer cylindrical thread arranged at ends thereof, coupler with inner thread and sealing means. Pipes are provided with screw grooves located beyond the thread and having pitch equal to thread pitch. Coupler comprises shoulder extending from center of inner surface thereof and with inner cylindrical surfaces abutting the shoulder. Coupler also has ring-like or left-handed screw grooves having diameters exceeding cylindrical thread diameter. Ring-like or screw grooves are located on inner surface between thread and coupler ends. Sealing means is made as resilient rings and resilient bushes. Resilient rings are installed at coupler shoulder on inner cylindrical surfaces and may contact with end surfaces of the pipes. Resilient bushes are installed on ring-like or screw grooves of the coupler and may contact with screw grooves of the pipes.

EFFECT: increased corrosion resistance of thread exposed to well fluid.

1 dwg