THREADED CONNECTION OF CASING PIPES Russian patent published in 2023 - IPC E21B17/42 E21B17/08 F16L15/00 

FIELD: pipe connections.

SUBSTANCE: claimed invention is related to coupling threaded connections for casing pipes and can be used to connect elements of casing pipe strings used for the construction of vertical, directional and horizontal wells in oil, gas, and gas condensate fields. The threaded connection of casing pipes contains male and female elements. At the ends of the male and female elements on the outer and inner surfaces, respectively, there are trapezoidal conical threads and sealing and thrust end surfaces forming the internal sealing unit. The peaks and valleys of the thread profile of the male and female elements are made parallel to the centre line of the thread. The internal seal assembly is equipped with additional surfaces located between the sealing and thrust end surfaces. Additional surfaces are made in form of a conical surface on the female element and in the form of a conical or convex spherical surface on the male element. The transition from the sealing surfaces to additional surfaces is made in form of a concave spherical surface on the male element and a convex spherical surface on the female element.

EFFECT: increased tightness of a threaded connection of casing pipes under the influence of combined multidirectional mechanical loads is ensured due to improved make-up characteristics of the connection, prevention of jamming of the connection at the initial stage of make-up and absence of damage to the sealing surfaces.

17 cl, 3 dwg