THREADED CONNECTION OF STEEL PIPES FOR OIL WELLS Russian patent published in 2020 - IPC F16L15/04 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to threaded pipe joint, used for connection of pipes for oil wells. Threaded connection includes a nipple part having an external thread, and a flared part having an internal thread engaged with an external thread, and on sealing portion on outer periphery side area S1 (mm²) of section of nipple part in sealing point in specified position and area S0 (mm²) of section of body of pipe, which is untreated section of nipple part, satisfies expression (S1/S0)×100≥15(%), on sealing section on inner periphery side area S2 (mm²) of the flared end section at the sealing point in the predetermined position and area S0' (mm²) of section of body of pipe, which is untreated section of flared part, satisfy expression (S2/S0')×100≥20(%), and area S3 (mm²) of surface of contact area of intermediate collar C between rows A and B of threads and area S0 (mm²) cross-sections satisfy expression (S3/S0)×100≥10(%).

EFFECT: invention is aimed at preventing plastic deformation and improving tightness of the joint.

1 cl, 3 dwg, 1 tbl