RU2719878C1 - Device for preventer crimping on well - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention is related to oil industry, in particular, to devices for preventer crimping at well and / or at bench well of production service base. Device for preventer crimping on well includes support pipe passing through preventer body, and rubber collar arranged on support pipe. Rubber collar is made in the form of a shaped elastic hose equipped with a leaf-shaped compactor from the outside, made from the inside in the form of an inverted cone narrowing downwards. Upper and lower ends of shaped elastic hose are rigidly fixed on support pipe. Supporting pipe is equipped with a row of radial holes made opposite the shaped resilient sleeve sealed from inside under action of hydraulic pressure. Outer surface of the support tube above the shaped elastic hose is first provided with a shaped slot, and then – with an external stepped annular recess, consisting of the lower and upper stages. Figured slot consists of longitudinal short and long sections. Opposite to shaped slot on outer surface of support tube there is a spring-loaded collet with guide pin arranged in shaped slot, wherein longitudinal short and long sections of shaped slot are connected to each other with closed shaped section so that during axial reciprocating movement of collet relative to support pipe guide pin will be located in longitudinal short section of shaped slot – transport position, in which collet interacts with lower step of external stepped ring recess of support pipe, then in longitudinal long section of shaped slot – working position. Collet interacts with the upper stage of external stepped ring recess of the support pipe. Lower end of the support pipe is equipped with a choke valve inside, and below it – with a rigid centralizer with external overflow channels. In initial position outer diameter dof rigid centralizer is larger than outer diameter dof shaped resilient sleeve.EFFECT: proposed device improves reliability of device operation, reduces labor consumption of device, eliminates damage to environment during operation of device, increases service life of device, simplifies device design.1 cl, 5 dwg

Description

The invention relates to the oil industry, in particular to devices for crimping a preventer at a well and / or at a bench well of a production service base.

 A device for crimping a preventer in a well is known (patent RU No. 2364701, IPC ЕВВ 33/03, published on 08/20/2009 in bull. No. 23), including a support pipe passing through the preventer body, two rubber cuffs with a washer between them, a support and a clamping plate, a plug with a female thread, a rod installed in the support tube for compressing rubber cuffs, and there is a cylindrical sample at the upper end of the clamping plate. When pressure testing the preventer, the force to compress the rubber cuffs is transmitted when the bolt is turned on a nut that is motionlessly wrapped in the sleeve of the support pipe. The bolt interacts on the rod, which moves down the plunger located in the sample clamping plate. In this case, the pusher passes through the longitudinal through groove of the support pipe. When moving down, the clamping plate presses on top of the rubber cuffs and increases them in diameter to isolate the bottom of the wellbore. The support plate in the prototype is located below the rubber cuffs, and the clamping plate is located on top of the rubber cuffs.

The disadvantages of the device are:

- firstly, the complexity of the design of the device due to the presence of a large number of nodes and parts (two rubber cuffs with a washer between them, a support and a clamping plate, a plug with an internal thread, a rod installed in the support pipe, etc.);

- secondly, low reliability at high pressures (25–35 MPa), due to the incomplete sealing design of the rubber cuff, since the rubber cuff is compressed by compressing it between the plug and the clamping plate and, accordingly, radially expanding the rubber cuff, therefore, with insufficient compression of the rubber seal at crimping pressures of 25–35 MPa, the probability of loss of tightness is high, which makes it impossible to pressure the preventer;

- thirdly, the complexity of the application, as a single-use device, i.e. after each crimping of the preventer, it is necessary to disassemble, revise, and assemble it, which increases the cost of servicing the device when crimping the preventer;

fourthly, low environmental safety, harmful to the environment, associated with the outflow of well fluid at the mouth when the device is lowered into the column head of the well for pressure testing. This is because the rubber cuffs, due to their design, during the descent of the device, squeeze out the liquid located in the column head of the well at the wellhead, in addition, it is necessary each time after the descent of the device into the column head, i.e. Before crimping the preventer, fill the column head of the well with process fluid;

fifthly, the low life of the rubber cuff, associated with wear and damage to the cuff during installation and removal of the device from the column head, due to the lack of external protection of the rubber cuffs during the hoisting operations (STR), as well as the lack of centering of the device in the process STR and crimping.

 The closest in technical essence is a device for crimping a preventer in a well (patent RU No. 2680618, IPC ЕВВ 33/03, publ. 02/25/2019 in bull. No. 6), including a support pipe passing through the preventer body and a rubber sleeve placed on support pipe. The device also includes a hollow rod installed in the support pipe, support and clamping plates, a plug with an internal thread, two rubber cuffs with a washer between them. The hollow stem is designed to compress rubber cuffs. At the upper end of the clamping plate there is a cylindrical selection. The hollow stem is made of a pipe having an external cylindrical thread at both ends, and the plug is made with an internal cylindrical thread, is wrapped in a cylindrical thread of the lower end of the stem and is equipped with a locking screw, and the support plate is located on top of the rubber cuffs and is pressed onto the support pipe, this clamping plate is located below the rubber cuffs and is made with a flat upper end. A washer of anti-friction material is put on the stem between the clamping plate and the plug. A sleeve with an internal cylindrical thread corresponding to the stem thread is installed on the inside of the support pipe from the upper end. The upper end of a hollow rod with a cylindrical thread is wrapped in this sleeve. A groove is made from the upper end of the hollow rod; two radial holes are made from the bottom of the groove located along the diameter of the hollow rod.

The disadvantages of the device are:

- firstly, low reliability at high pressures (25–35 MPa), due to the incomplete sealing design of the rubber cuff, since the rubber cuff is compressed by compressing it between the plug and the clamping plate and, accordingly, radially expanding the rubber cuff, therefore, with insufficient compression of the rubber seal at crimping pressures of 25–35 MPa, the probability of loss of tightness is high, which makes it impossible to pressure the preventer, or you have to tighten the clamping plates (press rubber sleeve) and the pressure test repeated preventer;

- secondly, the complexity of the application, as a single-use device, i.e. after each crimping of the preventer, it is necessary to disassemble, revise, and assemble it, which increases the cost of servicing the device when crimping the preventer;

- thirdly, low environmental safety, harmful to the environment, associated with the outflow of well fluid at the mouth when the device is lowered into the column head of the well for pressure testing. This is because the rubber cuffs, due to their design, during the descent of the device, squeeze out the liquid located in the column head of the well at the wellhead, in addition, it is necessary each time after the descent of the device into the column head, i.e. Before crimping the preventer, fill the column head of the well with process fluid;

fourthly, the low life of the rubber cuff associated with their wear and damage during installation and removal of the device from the column head, due to the lack of external protection of the rubber cuffs during the STR, as well as the lack of centering of the device during the STR and crimping;

- fifthly, the complexity of the design, due to the large number of nodes and parts (two rubber cuffs with a washer between them, support and clamping plates, a plug with an internal thread, a rod installed in the support pipe, etc.).

 The technical objectives of the invention are to increase the reliability of the device in operation, reduce the complexity of its use, increase the life of the device, improve environmental safety and simplify the design of the device.

Technical problems are solved by a device for crimping a preventer in a well, including a support pipe passing through the preventer body and a rubber sleeve placed on the support pipe.

What is new is that the rubber cuff is made in the form of a figured elastic sleeve, provided with an outer flap seal, made from the inside in the form of a reverse cone, tapering from top to bottom, while the upper and lower ends of the figured elastic sleeve are rigidly fixed to the support pipe, and the support pipe is equipped with a row radial holes made opposite to the inside, which is sealed from the inside under the influence of hydraulic pressure of a curly elastic sleeve, while the outer surface of the support pipe is higher than the curly elastic the first sleeve is equipped with a figured groove, and then an outer step ring selection consisting of lower and upper steps, the figured groove consisting of longitudinal short and long sections, while a collet spring-loaded outside with a guide pin is movably placed opposite the figured groove on the outer surface of the support pipe placed in a figured groove, while the longitudinal short and long sections of the figured groove are interconnected by a closed figured section so that with an axial reciprocating When the collet is positioned relative to the support pipe, the guide pin will be located either in the longitudinal short section of the figured groove - the transport position, in which the collet interacts with the lower step of the outer step ring selection of the support pipe, then in the longitudinal long section of the figured groove - the working position, while the collet interacts with the upper step of the outer stepped annular sampling of the support pipe, and the lower end of the support pipe inside is equipped with a knockdown valve, and below it is a rigid centralizer with external accurate channels, and in the initial position, the outer diameter d _{1 of the} hard centralizer is larger than the outer diameter d _{2 of a} curly elastic sleeve.

The figures 1 and 4, 5 schematically depict the proposed device for crimping the preventer in the well during operation.

In FIG. 2 - shows an A-scan of a figured groove made on a support pipe.

In FIG. 3 - section BB.

A device for crimping a preventer in a well includes a support pipe 1 (Fig. 1) passing through the casing 2 of the preventer 3 and a rubber sleeve 4 placed on the support pipe 1.

The rubber cuff 4 is made in the form of a figured elastic sleeve 5, in the lower part outside equipped with a petal seal 6, made with a gap from the inside in the form of an inverse cone 7, tapering from top to bottom. The inner part of the elastic sleeve is made with a gap. The elastic figured sleeve and the flap seal can be made of a pressure sleeve with a thread reinforcement unreinforced according to GOST 10362-76. Such sleeves consist of two rubber layers (outer and inner) and a thread frame to strengthen the structure. They are used as flexible pipelines for supplying liquids, inert gases and air under pressure.

The upper 8 and lower 9 ends of the elastic sleeve 5 are rigidly fixed to the support pipe 1.

The support pipe 1 is provided with radial holes 10 made opposite the inside of the elastic sleeve 5, which is compacted from the inside by the hydraulic pressure. The number of radial holes can be 2-4 with a diameter of 20 mm. The number of radial holes depends on the flow rate of the fluid supplied by the pump unit. The support pipe is made to simplify the manufacture of two parts connected by a threaded connection (shown in the figures conditionally).

The outer surface of the support pipe 1 above the curly elastic sleeve 5 is first equipped with a curly groove 11, and then the outer step ring selection 12, consisting of the lower 13 and upper 14 steps. Figured groove 11 consists

 from longitudinal short 15 (Fig. 2) and long 16 sections. Opposite the figured groove 11 (Fig. 1) on the outer surface of the support tube 1, a collet 17 spring-outwardly movable with a guide pin 18 located in the figured groove 11 is movably placed. a groove.

Longitudinal short 15 and long 16 sections of the figured groove 11 are interconnected by a closed figured section 19 (Fig. 2) so that upon reciprocating movement of the collet 17 (Figs. 1 and 4, 5) relative to the support pipe 1, the guide pin 18 will be located then in the longitudinal short section 15 (Fig. 2) of the figured groove 11, the transport position in which the collet 17 (Fig. 1) interacts only with the lower 13th step of the outer stepped annular selection 12 of the support pipe 1, then in the longitudinal long section 16 ( Fig. 2) of a figured groove 11 — operating position, in which collet 17 (Fig. 4) interacts with the upper 14th step of the outer stepped annular selection 12 of the support pipe 1. The lower end of the support pipe is equipped with a check valve 20, and above the overflow valve 21 (Fig. 1).

The support pipe 1 is provided with a rigid centralizer 22 from the bottom (Fig. 3) equipped with external transfer channels 23. The hard centralizer 22 is rigidly connected to the support pipe 1, for example, by means of a threaded connection.

In the initial position, the outer diameter d _{1 of the} hard centralizer 22 (FIGS. 1 and 3) is larger than the outer diameter d _{2 of the} shaped elastic sleeve 5.

A device for crimping a preventer in a well works as follows.

The device is assembled as shown in FIG. 1, while the guide pin 18 (Fig. 1) is installed in the transport position in the longitudinal short 15 portion of the figured groove 11 (Fig. 2). Then the device using the elevator 24 (Fig. 1 and 4) through the housing 2 (Fig. 1) of the preventer 3 with the open valve 25 of the pipe 26 is lowered into the column head 27 and then into the well 28, while the figured elastic sleeve 5 is not in contact with the inner walls of the well 28 and bypasses the fluid from the bottom up, also the check valve 20 opens under pressure from the bottom and the well fluid from the well 28 enters the support pipe 1. As the well 28 there may be a drill pipe, casing, etc.

The descent of the device is stopped 1–2 m before reaching the spring-loaded collet 17 of the coupling 29 of the well 28. After that, from the wellhead, lift the device up by about 0.75 m and lower it down, while the guide pin 18 from the longitudinal short section 15 through a closed figured section 19 of the figured groove 11 falls into a longitudinal long section 16 and moves to the upper part of the latter, occupying a working position. The descent of the device down continues until the collet 17 falls into the gap of length b of the coupling 29 of the well 28, while the collet 17 spring-loaded out of contact with the lower stage 13, diverges outward and abuts against the upper stage 14 of the outer step ring sample 7 The descent of the device into the well is stopped, since the device is fixed in the well 28, and the inequality must be observed:

    a <b

where, a is the height of the fixing part of the collet 17, mm, for example, 18 mm;

        b - coupling clearance height 29, mm, for example, 23 mm.

After fixing the device in the well, the check valve 20 closes (lowers) under its own weight, i.e. hermetically closes the bottom passage opening in the support pipe 1.

The centralizer 22, having an outer diameter d ₁ greater than the outer diameter d _{2 of the} curly elastic sleeve 5, eliminates the contact of the outer surface of the curly elastic sleeve 5 with the walls of the column head 27 during the descent of the device into the column head 27 of the well 28.

Next, install the elevator 24 (Fig. 4) under the sleeve of the support pipe 1. Bind the pump 30 with the first discharge line 31 with the upper end of the support pipe 1, and with the help of the second discharge line 32 with the nozzle 26. Any pump can be used as pump 30 known design, designed for pumping fluid into the well, for example cementing unit brand CA-320, manufactured by LLC "Izhneftegaz" (Russian Federation, Republic of Udmurtia, Izhevsk).

Close the valve 25 on the nozzle 26 and pump technological fluid, for example, fresh water with a density of 1020 kg / m ^3, into the support tube 1 and then through the radial holes 10 into the inner cavity 33 of the elastic figured sleeve 5. In the inner cavity 33 of the elastic figured sleeve 30 5 with the help of the pump 30 create excess pressure, for example 8.0 MPa, due to which the shaped elastic sleeve 5 expands radially and is pressed against the inner walls of the well 28. Continue to increase the excess pressure, for example up to 10.0 MPa, while m flap seal 6, made with a gap from the inside in the form of a reverse cone 7, tapering from top to bottom, is pressed against the inner walls of the well 28, providing a tight and tight fit figured elastic sleeve 5 in the well 28.

Close the valve 34 on the first discharge line 31 of the pump 30, while maintaining an excess pressure of 10.0 MPa in the inner cavity 33 of the figured elastic sleeve 5.

Then fill the well 28. To do this, open the valve 25 of the nozzle 26 and use the pump 30 to pump the process fluid along the second injection line 32 through the nozzle 26 into the space of the column head 27 of the well 28 above the shaped elastic sleeve 5 until the overflow of the process fluid through the elastic plates 35 of the preventer 3 .

Then the rotation of the steering wheel (in Figs. 1, 4, 5 is shown conditionally) by 7–10 revolutions of the drive 36 (Fig. 4) of the preventer 3 is carried by the elastic dies 35 of the preventer 3 to each other. Dies 35 hermetically compress the outside of the support pipe 1.

Then, the process fluid is continued to be pumped through the second injection line 32 through the nozzle 26 into the space of the column head 27 of the well 28 above the shaped elastic sleeve 5 and the pressure is raised to the intended pressure of pressure testing of the preventer, for example, equal to 25.0 MPa, while the generated overpressure will be from one the sides to act on the figured elastic sleeve 5, sealed to the inner walls of the well 28, and on the other hand to act on the dies 35, hermetically compressing the support pipe 1. Withstand Center 3 under the above pressure, for example, for 30 minutes, and a pressure drop of more than 5% is not allowed, i.e. after the end of the crimping time, the overpressure should not be lower than 23.75 MPa. Thus, pressure testing of the preventer 3 is carried out.

After pressure testing of the preventer 3, the valves 34 and 25 are opened and the overpressure is vented to atmospheric pressure in the inner space of the support pipe 1 and the space of the column head 27 of the well 28 above the shaped elastic sleeve 5, respectively. Next, the first 31 and second 32 discharge lines of the pump 30 are dismantled.

As a result, the shaped elastic sleeve 5 is compressed radially inward and moves away from the inner walls of the well 28, occupying the transport position (Fig. 1).

By rotating the steering wheel 7-10 revolutions of the drive 36 of the preventer 3, the dies 35 of the preventer 3 are pushed apart from each other. Dies 35 go out of interaction with the support pipe 1.

Then, from the wellhead, a load is dumped into the support pipe, for example, a metal bar with a diameter of 25 mm and a length of 1 m, which destroys the relief valve 21.

Then, from the wellhead, the device is lifted by the support pipe 1 using the elevator 24 upwards by about 1 m and lowered downward, while the guide pin 18 (Figs. 1 and 2) from the long longitudinal section 16 through the closed figured section 19 of the figured groove 11 enters in the longitudinal short section 15 and moves to the upper part of the latter, occupying the transport position, while the collet 17 spring-loaded outside (Fig. 4) is under the lower step 13 of the outer step ring sample 12 and leaves the clearance of the coupling 29 of the well 28. Next, build up the device and remove it from the well 28.

When removing (lifting) the device from the well 28, the process fluid freely flows from top to bottom from the support pipe 1 through the destroyed hole of the relief valve 21 into the space of the well 28 below the figured elastic sleeve 5, while the check valve 20 is closed. This allows you to lift the device without overflowing at the wellhead 28.

Due to the fact that the rubber cuff 4 is made in the form of a figured elastic sleeve 5, provided with an outer flap seal 6, made from the inside in the form of a return cone 7, tapering from top to bottom, the reliability of the device at high pressures increases (25–35 MPa), since by increasing the overpressure, the flap seal 6, made internally in the form of a return cone 7, tapering from top to bottom, is pressed against the inner walls of the well 28. This reduces the likelihood of loss of tightness of the device during the process all pressure testing of the preventer.

The cost of servicing the device is reduced when pressure testing the preventer at the well, which means that financial costs are reduced. This is due to a decrease in the laboriousness of using the device, since the proposed device is reusable, therefore, after each pressure testing of the preventer, it is not necessary, as described in the prototype, to disassemble, revise, and assemble it, and it is only necessary to replace the destroyed knock-off valve 21 after pressure testing the preventer 3.

The environmental damage is reduced by eliminating the outflow of the borehole fluid at the wellhead, since when the device is launched, the fluid in the borehole flows freely from the borehole 28 under the device into the borehole 28 above the device above the rubber cuff 4, made in the form of a figured elastic sleeve 5, through the external transfer channels 23 of the hard centralizer 22 and into the support pipe 1 through the open check valve 20.

When lifting the device from the column head 27 of the well, the liquid flows from top to bottom from the space of the well 28 above the device into the space of the well 28 under the device through the external transfer channels 23 of the rigid centralizer 22, and from the support pipe 1 flows through the hole of the destroyed knockoff valve 21 with the non-return valve 20 closed into the space of the well 28 under the device.

Also, there is no need every time when testing each subsequent preventer 3 after the device is lowered into the well, to fill the well 28 with process fluid.

The service life of the device is increased due to reduced wear and damage to the curly elastic sleeve 5, allowing it to be centered using a rigid centralizer 22 relative to the axis of the well 28 during the descent, sealing and removal of the device.

The design of the device is simplified, since, in comparison with the prototype, rubber cuffs with a washer between them, supporting and clamping plates, a plug with a female thread, etc. are excluded

The proposed device for crimping the preventer in the well allows you to:

- increase the reliability of the device;

- reduce the complexity of the device;

- exclude harm to the environment;

- increase the life of the device;

- simplify the design of the device.

Claims (1)

A device for crimping a preventer in a well, including a support pipe passing through the preventer body and a rubber sleeve placed on the support pipe, characterized in that the rubber sleeve is made in the form of a figured elastic sleeve provided with an outer tab, made from the inside in the shape of a cone, tapering from top to bottom, while the upper and lower ends of the figured elastic sleeve are rigidly fixed to the support pipe, and the support pipe is equipped with a number of radial holes made for a flexible elastic sleeve, which is compacted from the inside under hydraulic pressure, while the outer surface of the support pipe above the elastic sleeve is first equipped with a figured groove, and then with an outer step ring selection consisting of lower and upper steps, and the figured groove consists of longitudinal short and long sections, while opposite the figured groove on the outer surface of the support pipe movably placed outside spring-loaded collet with a guide pin located in the figured a joint, while the longitudinal short and long sections of the figured groove are interconnected by a closed figured section so that with axial reciprocating movement of the collet relative to the support pipe, the guide pin will be located then in the longitudinal short section of the figured groove - the transport position in which the collet interacts with the lower step of the outer stepped annular sampling of the support pipe, then in the long longitudinal section of the curly groove is the working position, while the collet interacts with the upper step aruzhnoy stepped annular sample support tube, with the lower end of the support tube is equipped inside a valve whipped egg-white, and below - the rigid centralizer with external downcomers, and in the rest position, the outer diameter d ₁ rigid centralizer larger than the outer diameter d of figure ₂ the elastic sleeve.

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