RU2509863C1 - Connection of shaped tubes of shutters of wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: connection of shaped tubes of well shutters includes shaped tubes with cylindrical ends, which are equipped with sleeved and nipple thread on mutually facing surfaces. Besides, there are sealing devices of the connection, which are made in the form of two elastic rings. One of the rings is installed in an expanded annular coupling end on the side of internal joint of thread between the mutually facing cylindrical surfaces of the threaded and annular sections. In the nipple end there is a constriction for the second elastic ring on the side of an external joint of thread between the mutually facing cylindrical surfaces of the threaded and annular sections. The external joint is made in the form of tightly adjoining and mutually facing conical tube surfaces. Above and/or below the threaded connection on the cylindrical section there is a constriction in the form of alternating annular bulges and cavities. An elastic cuff is welded on the outer surface of the constriction flush with the cylindrical section.

EFFECT: reducing stiffness of the connection cross section and excluding liquid flow between walls of the shutter and the well.

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Description

The invention relates to the oil and gas industry, in particular to the connections of profile pipes between themselves, expandable in the process of overlapping them with zones of drilling complication or leakage of casing strings in wells.

It is known to connect profile pipes of well shutoffs (a.s. USSR No. 1367586, ЕВВ 33/12, published in Bull. No. 33 of 11/27/1996), containing profile pipes, the connected ends of which are cylindrical and threaded on mutually reversed surfaces as well as means of sealing the connection, while the ends to be connected are made with collars formed by radially expanded annular sections, and sealing means are made in the form of elastic rings, one of which is located between the mutually reversed ends of the collars on the outer surface of the connection with the possibility of overlapping the outer joint, and the second in the expanded annular section from the side of the inner joint of the thread between the mutually inverted cylindrical surfaces of the threaded and annular sections, while the thread is cylindrical with a rectangular profile.

The disadvantages of this connection are the difficulty of manufacturing radially expanded annular sections (shoulders), as well as the ability to extrude the elastic ring from the side of the internal joint of the thread and its damage by the tool with an increase in the diameter of the overlap. In addition, in the case of a loose pressing of the overlap against the walls of the well, the external sealing element does not ensure the tightness of the threaded connection.

The closest in technical essence and the achieved result is the connection of profile pipes of the overlap wells (patent for utility model No. 56932, ЕВВ 29/10, published in Bul. No. 27 of 09/27/2006), containing profile pipes, the connected ends of which are made cylindrical and equipped with coupling and nipple threads on mutually reversed surfaces, as well as means of sealing joints made in the form of two elastic rings, one of which is installed in the expanded annular coupling end from the side of the inner joint thread s vzaimoobraschennymi between cylindrical surfaces, and the annular threaded portions formed in the pin-end by restriction second elastic ring by the outer thread joint between vzaimoobraschennymi threaded cylindrical surfaces and annular portions, wherein an outer joint is designed as a conical vzaimoobraschennyh tightly adjacent surfaces of the tubes.

The disadvantage of this connection is the increased stiffness of the cross section, depending on the moment of resistance to bending, which is the reason for the non-passage of the overlap into the well at intervals with a high intensity of bending of the bore. In addition, the absence on its outer surface of the sealing element (packer) does not exclude the flow of fluid between the walls of the installed shutoff and the well.

The technical objectives of the proposed connection profile pipes are to reduce the rigidity of the cross section and the exclusion of fluid flow between the walls of the overlap and the well.

Technical problems are solved by connecting the profile pipes of the well shutoffs, containing profile pipes, the connected ends of which are made cylindrical and equipped with sleeve and nipple threads on mutually reversed surfaces, as well as sealing means of the connection made in the form of two elastic rings, one of which is installed in the expanded annular sleeve end from the side of the internal joint of the thread between the mutually inverted cylindrical surfaces of the threaded and annular sections, at the nipple end you olneno restriction under the second resilient ring by the outer thread joint between vzaimoobraschennymi threaded cylindrical surfaces and annular portions, wherein an outer joint is designed as a conical vzaimoobraschennyh tightly adjacent surfaces of the tubes.

What is new is that above and / or below the threaded joint in the cylindrical section, narrowing was performed in the form of alternating annular thickenings and depressions, on the outer surface of which an elastic cuff is welded flush with the cylindrical section.

Figure 1 shows the connection of the profile pipes of the overlap wells (section); figure 2 - connection of profile pipes of the overlap, lowered into the well, after the passage of the tool, increasing it to the diameter of the well (section).

The connection (Fig. 1) consists of profile pipes 1 and 2, the connected ends of which 3 and 4 are made cylindrical and equipped with a coupling 5 and nipple 6 threads on mutually reversed surfaces, as well as from the sealing means of the connection made in the form of two elastic rings 7 and 8 , one of which 7 is installed in the expanded annular sleeve end 9 from the side of the internal joint of the thread between the mutually inverted cylindrical surfaces 9 and 10. At the nipple end 4, a narrowing 11 is made under the second elastic ring 8 from the side of the outer joint re threads between the mutually inverted cylindrical surfaces 11 and 12, and the outer joint of the connection is made in the form of conical tightly adjacent mutually inverted surfaces 13 and 14 of the pipes 1 and 2, respectively.

Above (not shown, similarly to the bottom) and / or below the threaded connection on the cylindrical section 15, a narrowing 16 is made in the form of alternating annular thickenings 17 and depressions 18, on the outer surface of which 19 an elastic sleeve 20 is welded flush with the cylindrical section.

The connection works as follows. Profile pipes 1 and 2 are screwed respectively with ends 3 and 4 with their sleeve 5 and nipple 6 threads at the wellhead, while monitoring the integrity of the elastic rings 7 and 8. The surfaces 13 and 14, respectively, of pipes 1 and 2 are tightly in contact, fixing them from self-unscrewing when flaring the overlap. Next, lower the shutter on the drill pipe string (not shown) to the interval of its installation. Moreover, the narrowing 16, made on the cylindrical section 15 in the form of alternating annular thickenings 17 and depressions 18 with the cuff 20, contributes to the free passage of the overlap in the intervals with a high intensity of curvature of the trunk. By pumping the liquid, the pressure inside the overlap is increased, and the profile parts of the pipes 1 and 2 are straightened out. During this operation, the elastic ring 7 assumes the internal pressure and seals the threaded joint until the profile parts of the pipes 1 and 2 are completely straightened. Then they expand with a flare or mandrel cylindrical sections of the joints until they fit snugly against the walls of the well 21 (FIG. 2). At the same time, the cylindrical section 10 (Fig. 1) of the nipple end 4, while expanding, partially enters the expanded annular sleeve end 9, compressing the elastic ring 7, which reliably seals the connection from the action of internal pressure. At the same time, the cylindrical section 12 of the coupling end 3 partially enters the narrowing 11 of the nipple end 4. In this case, the elastic ring 8 is compressed, sealing the connection from the action of external pressure. The elastic cuff 20 is compressed by pressure from the extended portion of the pipe and wall connection, eliminating fluid flow between them.

The advantage of the proposed connection of the profile pipes of the well shutoffs is that due to the narrowing located above and / or below the threaded joint made in the cylindrical section in the form of alternating annular thickenings and depressions, the cross-section stiffness is reduced, which contributes to the free passage of the overlap into the well in intervals with high intensity curvature of the trunk. In addition, after expanding the flare joint, an elastic cuff that is welded to the outer surface of the cylindrical section eliminates fluid flow between the walls of the shutoff and the well.

Claims (1)

The connection of the profile pipes of the shutoffs of wells, containing profile pipes, the connected ends of which are cylindrical and equipped with coupling and nipple threads on mutually reversed surfaces, as well as sealing means of the connection, made in the form of two elastic rings, one of which is installed in the expanded annular coupling end from the inside the joint of the thread between the mutually inverted cylindrical surfaces of the threaded and annular sections, at the nipple end, a narrowing was made for the second el a mating ring from the side of the external thread joint between the mutually inverted cylindrical surfaces of the threaded and annular sections, wherein the outer joint is made in the form of conical tight-fitting mutually inverted pipe surfaces, characterized in that above and / or below the threaded connection on the cylindrical section, narrowing is performed in the form of alternating annular thickenings and depressions, on the outer surface of which an elastic cuff is welded flush with the cylindrical section.

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