CASING THREADED CONNECTION Russian patent published in 2019 - IPC E21B17/42 E21B17/08 F16L15/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to threaded joints of casing pipes and can be used for connection of elements of casing string used for attachment of vertical, directional and horizontal wells at oil, gas and gas condensate fields. Threaded connection of casing pipes includes nipple and coupling elements, on ends of which on outer and inner surfaces, respectively, there are trapezoidal tapered threads, main and auxiliary sealing surfaces and thrust end surfaces. Vertices and recesses of profile of thread turn are parallel to axial line of thread. Auxiliary sealing surfaces are located in front of the main sealing surfaces relative to thrust end surfaces.

EFFECT: improved characteristics of joint spinnability, preservation of joint tightness at action of differently directed loads under conditions of multiple screwing-unscrewing.

13 cl, 1 tbl, 2 dwg