AIR-TIGHT THREADED OIL-FIELD PIPE CONNECTION Russian patent published in 2007 - IPC E21B17/42 F16L15/00 

FIELD: oil and gas well construction, particularly threaded couplings and joints between rod and bit, or between rod and rod.

SUBSTANCE: air-tight threaded connection includes male and female pipes with conical threading and conical seat surfaces. The first conical surfaces cooperate with each other and are correspondingly made on outer surface of female pipe end as conical surface oblique along pipe axis and on inner surface of female pipe between conical threading and pipe body. The second conical surfaces are created on male pipe as end conical surface with oblique angle defined in pipe axis and mating end conical surface made on female pipe in transition pipe section between the first conical surface and the pipe body. Conical threading has 1:16 obliquity. Conical seat surfaces formed on outer surface of male pipe end and on inner surface of female pipe end have 1:10 obliquity in pipe axis direction. Conical end surfaces have 15° angle of taper in direction of conical threading made in corresponding pipe. Annular groove for oil forcing is made in female pipe in transition section between conical threading and pipe body. Conical Battress-type threading having 13° threading angle has threads with cross-section defining unequal-sided trapeze. Support edge of each thread extends at increased angle to load application direction.

EFFECT: increased efficiency.

3 dwg