RU-2861573-C1 - SEALED THREADED CONNECTION

RU2861573C1RU 2861573 C1RU2861573 C1RU 2861573C1RU-2861573-C1

Abstract

FIELD: oil and gas industry. SUBSTANCE: invention can be used in the construction of oil and gas wells. The sealed threaded pipe connection includes a pin (1) and a box (2) with threads (3), shoulder and sealing surfaces, contacting over the entire surface of the shoulder-seal thread profile, and shoulder (12, 13) and sealing surfaces (5, 7, 8, 9) of the "cone-cone" type, forming "metal-to-metal" sealing units. The profile of the shoulder-seal thread is made in the form of an unequal trapezoid with a positive shoulder surface angle. The shoulder-seal thread (3) is divided into two sections located at different height levels relative to each other. On the pin (1) and box (2) between the shoulder-seal threads (3) there is a section with conical end shoulder-seal surfaces (12, 13). On the pin (1) and box (2) before the thread start located at different height levels relative to each other, cylindrical bores (14, 15) are made. A cylindrical bore (6, 10) is made on the end surface of the pin and box. EFFECT: increased tightness of the threaded connection. 1 cl, 5 dwg

Inventors

ASLANOV MUSTAFA AZHDAR OGLY
DZHAFAROV RIAD DZHAKHID OGLY
Akolzin Vadim Khangusejnovich

Dates

Publication Date: 20260506
Application Date: 20251016

Claims (1)

A hermetically sealed threaded joint comprising male and female pipes with a cylindrical thrust-sealing thread of a trapezoidal profile with a positive angle of the thrust surface and conical sealing surfaces formed on the outer surface of the male and inner surfaces of the female pipes, respectively, in which the thread is made in two levels with a separation of the levels by a conical thrust section with a negative angle of inclination and a cylindrical bore between the thread at the corresponding level and the conical thrust section, and conical sealing surfaces on each of the pipes are made between the outer end and the thread and the inner end and the thread, respectively, wherein additional cylindrical bores are made between the corresponding conical thrust surface and the thread.

Description

The invention can be used in the construction of oil and gas wells. A hermetically sealed threaded connection for oilfield tubing is known from the prior art, according to Russian Patent No. 76099 for Utility Model. It comprises male and female pipes with tapered threads, thrust and sealing surfaces. The thrust surfaces contact each other through the end surface on the male pipe and the mating end surface on the female pipe. The tapered thread profile has a negative angle along the bearing face. The thread profile height of the male pipe is less than the thread profile height of the female pipe. The end surfaces are enlarged such that their area constitutes at least 60% of the pipe body. The technical solution described in this patent improves the operational reliability and efficiency of the hermetically sealed connection, while also minimizing environmental risks. The objective underlying the development of the claimed solution is to further improve the operational and production parameters of the connection, while the technical result achieved by solving the stated problem consists of increasing the density (tightness) of the threaded connection regardless of the direction of pressure application, as well as reducing the required tightening torque and expanding the possibility of multiple re-tightening of products. In order to achieve the set result, a hermetically sealed threaded connection is proposed, containing male and female pipes with a cylindrical thrust-sealing thread of a trapezoidal profile with a positive angle of the thrust surface and conical sealing surfaces formed on, respectively, the outer surface of the male and inner surface of the female pipes, in which the thread is made two-level, with a separation of the levels by a conical thrust section with a negative angle of inclination and a cylindrical bore between the thread at the corresponding level and the conical thrust section, and conical sealing surfaces on each of the pipes are made between, respectively, the outer end and the thread and the inner end and the thread, while between the corresponding conical thrust surface and the thread, additional cylindrical bores are made. Fig. 1 shows a diagram of the claimed hermetically sealed threaded connection ; Fig. 2 - profile of the declared thread; in fig. 3 - view A in Fig. 1; in Fig. 4 - view B in Fig. 1; in fig. 5 - view B in FIG. 1. The possibility of achieving the desired result in terms of increasing the density (tightness) of the threaded connection is due to the following. When performing the screwing operation of the joint, the male (1) and female pipes (2) initially interact with each other by means of a thrust-sealing thread (3) made at different heights relative to each other. With reference to Fig. 3, the conical sealing surface (4) of the male pipe (1) advances along the conical sealing surface (5) of the female pipe (2) with the simultaneous formation of a cavity (6). Then, the conical sealing surface (5) interacts with the conical sealing surface (4 ), simultaneously with this, the deformation of the bore section (7) on the male pipe (1) begins, whereby, due to the resulting diametrical deformations of these surfaces, a "metal-to-metal" sealing unit is created. Similarly, with reference to Fig. 4, with the relative movement of the pipes, the conical thrust section (12) of the male pipe (1) also moves along the conical thrust section (13) of the female pipe (2) with the simultaneous formation of a cavity (14, 15), whereby due to the deformation of the bore section (7, 11) on the male (1) and female (2) pipes, respectively, the surface of the male pipe (1) is inclined and the female pipe (2) is inclined, due to which the thrust section of the male and female pipes is pressed, which improves the tightness of the contact on the sealing units. Similarly, with reference to Fig. 5, during the screwing process, the conical sealing surface (8) of the male pipe (1) also moves along the conical sealing surface (9) of the female pipe (2), with the simultaneous formation of a cavity (10). Further, the conical sealing surface (8) interacts with the conical sealing surface (9), simultaneously with this, the deformation of the bore section (11) on the female pipe (2) begins, and due to the resulting diametrical deformations of these surfaces, a "metal-to-metal" sealing unit is created. The presence of cylindrical bores on the male (1) and female (2) pipes eliminates the influence of burrs that form during thread cutting when the thread-forming tool is retracted at the thread runout, at the edges of the thread crests, and along the inner diameter of the female component. These burrs can interfere with thread engagement and affect sealing performance. When making up a threaded connection, the thread runout areas are always located within the bores, eliminating the influence of the thread surface at the runout area and the precision of the interaction between the male and female pipe surfa