THREADED CONNECTION WITH LOW MAKEUP TORQUE Russian patent published in 2017 - IPC E21B17/42 F16L15/00 

FIELD: mining.

SUBSTANCE: group of inventions relates to drilling and development of oil and gas deposits. Pipe threaded connection (30) comprises the first tubular element, screwed on the second tubular element. First tubular element comprises the first cylindrical tool joint (C1) with rotation axis (X), at the end of which there is an external stop (BE), Note here that said outer thrust (BE) is connected to the outer circle of the first tool joint in compliance with fourth profile (44) outer diameter, increasing from outer thrust to the first tool joint, and is connected to the male connection part (Hardware), elongated nonthreaded end part (PT1) forming the internal surface of the stop (B1) on axial end, so that the internal support (B1) is connected to the inner circle of the first tool joint in accordance with the first section (41) of internal diameter, decreasing from inner thrust to inner part of the first tool joint. Second tubular element has a second cylindrical tool joint (C2), forming on the free end support surface (SA) for external stop. Note here that said support surface is connected to the outer circle of the second tool joint in accordance with the third profile (43) outer diameter, increasing from support surface to tool joint, at that, on its inner surface of the tool joint comprises initial nonthreaded part (PT2) connecting the support surface with female threaded connecting part (PC2), intended for coupling with the enveloped threaded connecting part, and at the end of which is internal collar (E1) opposite internal support, the internal collar is connected to the inner circle of the second tool joint in accordance with the second profile (42) of internal diameter decreasing from inner collar to the inner part of the tool joint. Note here that at least one of the first and second profile is convex or concave. Length (L1, L2) of the first section (41) and/or the second profile (42) along the axis of rotation is more than (1/16") 1.5875 mm and less than length of the end part (PT1) and/or length (L3, L4) of the third section (43) and/or the fourth profile (44) along the axis of rotation is more than (1/16") 1.5875 mm and smaller than that of initial part (PT2).

EFFECT: technical result is accurate determination of optimal value of moment of screwing the connection.

15 cl, 11 dwg