THREADED CONNECTION OF OIL COUNTRY TUBULAR GOODS Russian patent published in 2024 - IPC F16L15/00 F16L15/06 

FIELD: threaded connections.

SUBSTANCE: invention relates to threaded joints of steel tubular goods of oil field used in oil and gas wells. Threaded connection of oil country tubular goods comprises a nipple element and a socket element, fastened by screwing the nipple element, which comprises on outer surface section of male thread, into a socket element having a female thread section on the inner surface. Male thread of nipple element and female thread of socket element are conical, with negative angles of inclination of support and embedded sides, with constant pitch between support sides and constant pitch between embedded sides. At that, width of tops of thread of nipple and socket elements decreases in direction of end surface of considered element, and the width of the thread recesses of the nipple and socket elements increases in the direction of the end surface of the considered element. Male thread profile recess is straight, and the peak of the female thread profile is a curved line and contains in the central part a convex arc of a circle with radius R₁ equal to 100÷300 mm. In the state after mechanical screwing of the connection, the support sides of the male thread are in contact with the support sides of the female thread, embedded sides of the male thread are in contact with the embedded sides of the female thread, male thread recesses are in contact with female thread peaks, and there is a gap between male thread peaks and female thread recesses.

EFFECT: invention improves tightness of threaded connection and its resistance to increased torque, as well as increases resistance of threaded sections to abrasion.

8 cl, 7 dwg