RU2708737C1 - Device for preventer pressing round on well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and is intended for the preventer in the well hydraulic testing. Device for preventer pressing round on well includes support pipe passing through preventer housing, hollow rod installed in supporting pipe and rubber collar arranged on support pipe. From below support pipe is equipped from top to bottom with top and bottom rows of radial channels, and on support pipe is rigidly fixed upper and lower sleeves, between which there is a rubber collar made in the form of a self-sealing collar. Support pipe is equipped with through longitudinal slots, in which pins are installed, which on one side are connected to casing, installed on external surface of housing under lower bushing, and on the other side with hollow rod plugged from above, which is placed inside support pipe, and in initial position hollow rod from above hermetically covers upper row of radial channels of support pipe, and from below hollow rod hydraulically communicates space under support pipe with space above self-sealing collar by through longitudinal channels made in hollow rod opposite lower row of radial channels of support pipe. In initial position, self-sealing collar is located inside jacket, and in working position, casing and hollow rod have the possibility of axial restricted movement along through longitudinal grooves of support pipe until casing stop in external cylindrical projection made on lower end of support pipe. Hollow rod tightly covers the lower row of the radial channels of the support pipe, at that the support pipe is equipped from below with a rigid centralizer equipped with external overflow channels and a spring-loaded casing from below. Outer diameter d₁ rigid centralizer is larger than outer diameter d₂ of casing accommodating self-sealing collar in initial position, wherein upper end of support pipe is hydraulically connected to pump.

EFFECT: proposed device for preventer pressing round at the well allows improving operating reliability, reducing labor intensity of application, excluding damage to environment during operation of the device and increasing service life.

1 cl, 3 dwg

Description

The invention relates to the oil industry and is intended for crimping a preventer at a well.

A device for crimping a preventer in a well is known (patent RU No. 2364701, IPC ЕВВ 33/03, publ. 08/20/2009 in bull. No. 23), including a support pipe passing through the preventer housing, 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, support and clamping plates, a plug with 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 pressures of 10–15 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 pressure testing 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, published on 02/25/2019 in bull. No. 6), including a support pipe passing through the preventer housing installed in the support pipe hollow rod and rubber sleeve located on the support pipe. The device also includes support and clamping plates, a plug with 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, the plug being made with an internal cylindrical thread, wrapped in a cylindrical thread of the lower end of the stem and provided with a locking screw, the support plate located on top of the rubber cuffs and press-fit 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 pressures of 10–15 MPa, there is a high probability of loss of tightness, 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, since the device is disposable, 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 pressure testing 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.

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, increase environmental safety.

The stated technical problems are solved by a device for crimping a preventer in the well, including a support pipe passing through the preventer body, a hollow rod installed in the support pipe and a rubber sleeve placed on the support pipe.

What is new is that from the bottom the support pipe is equipped with top and bottom rows of radial channels from top to bottom, with the upper and lower bushings rigidly fixed to the support pipe between which a rubber cuff is installed, made in the form of a self-sealing cuff, while the support pipe is equipped with through longitudinal grooves, which are installed fingers, which are on the one hand connected to a casing mounted on the outer surface of the housing under the lower sleeve, and on the other hand, with a hollow rod plugged from above placed inside the support of the pipe, and in the initial position, the hollow rod from above tightly closes the upper row of radial channels of the support pipe, and from below the hollow rod hydraulically communicates the space under the support pipe with the space above the self-sealing cuff by means of through longitudinal channels made in the hollow rod opposite the lower row of radial channels of the support pipe moreover, in the initial position, the self-sealing cuff is inside the casing, and in the working position, the casing and the hollow stem have the possibility of axial limited movement through the longitudinal longitudinal grooves of the support pipe to the stop of the casing in the outer cylindrical protrusion made on the lower end of the support pipe, while the hollow rod hermetically seals the lower row of radial channels of the support pipe, and the support pipe is equipped with a rigid centralizer equipped with external overflow channels from the bottom and from the bottom spring-loaded casing, and the outer diameter d _{1 of the} hard centralizer is larger than the outer diameter d _{2 of the} casing in which the self-sealing cuff is in the initial position, while the upper end of the supports Noah pipe hydraulically connected to the pump.

Figure 1 and 2 schematically shows the proposed device for crimping the preventer on the well in the initial and operating positions.

In FIG. 3 is a section AA of the device.

The device for crimping the preventer in the well includes a support pipe 1 (Fig. 1) passing through the housing 2 of the preventer 3.

From the bottom, the support pipe 1 is equipped from top to bottom with the upper 4 and lower 5 row of radial channels. On the support tube 1, the upper 6 and lower 7 bushings are rigidly fixed, between which a rubber sleeve 8 is installed, made in the form of a self-sealing sleeve. The upper 6 and lower 7 bushings are fixed to the support pipe 1 rigidly, for example, using a threaded connection.

The support pipe 1 is provided with through longitudinal grooves 9. The fingers 10 are installed in the through longitudinal grooves 9 of the support pipe 1, which are connected on one side to a casing 11 mounted on the outer surface of the support pipe 1, under the lower sleeve 7. And on the other hand, the fingers 10 are rigidly connected to the top of the hollow rod 12, placed inside the support pipe 1.

In the initial position, the hollow rod 12 from above seals the upper row of 4 radial channels of the support pipe 1, and from below the hollow rod 12 hydraulically communicates the space 13 under the support pipe 1 with the space 14 above the self-sealing sleeve 8 by means of through longitudinal channels 15 made in the hollow rod 12 opposite bottom row 5 of the radial channels of the support pipe 1.

In the operating position, the casing 11 and the hollow stem 12 have the possibility of axial limited movement along the through longitudinal grooves 9 of the support pipe 1 with the opening of the upper row 4 of the radial channels of the support pipe 1 until the casing 11 rests in the outer cylindrical protrusion 16 made on the lower end of the support pipe 1. In this case, the hollow rod 12 hermetically seals the bottom row 5 of the radial channels of the support pipe 1.

In the initial position, the self-sealing sleeve 8 is located inside the casing 11. The support pipe 1 is provided with a rigid centralizer 17, equipped with external overflow channels 18. The rigid centralizer 17 is rigidly connected to the support pipe 1, for example, by means of a threaded connection.

Rigid centralizer 17 springs from below the spring 19 of the casing 11, and the outer diameter d _{1 of the} hard centralizer 17 is larger than the outer diameter d _{2 of the} casing 11, in which there is a self-sealing cuff 8 in its original position.

The tightness of the device during the movement of the hollow rod 12 relative to the support pipe 1 is provided by the sealing rings 20.

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

The device is assembled as shown in FIG. 1 and with the help of the elevator 21 and with the gate valve 22 open, the nozzle 23 of the column head 24 is lowered down through the body 2 of the preventer 3 to the location of the self-sealing sleeve 9 under the nozzle 23 in the column head 24 of the well.

During the descent of the device, the channel 25 (Figs. 1 and 3) of the hollow rod 12 is filled with liquid in the well, which freely flows upward from the space 13 under the support pipe 1 into the space 14 above the self-sealing sleeve 8 through the through longitudinal channels 15 of the hollow rod 12 (Figs. 1 and 2).

After the location of the self-sealing cuff 8 (figure 1) under the pipe 23 in the column head 24 of the well of the hollow rod 12, an elevator 21 is installed under the sleeve 26 of the support pipe 1.

The rotation of the steering wheel (shown in Fig. 2 conventionally) for 7-10 revolutions of the drive 27 (Fig. 2) of the preventer moves the preventor dies 28 to each other. Dies 28 hermetically compress the outside of the support pipe 1.

The centralizer 17, having an outer diameter d ₁ greater than the outer diameter d _{2 of the} casing 11, eliminates the contact of the outer surface of the casing 11 with the walls of the column head 24 during the descent of the device into the column head 24 of the well. Add space 14 to the overflow of the process fluid through the pipe 22, then close the valve 22 and create an overpressure in it, for example 5.0 MPa. The pump 29 is tied with the upper end of the support pipe 1 and the process fluid, for example fresh water with a density of 1000 kg / m ^3, is pumped into the support pipe 21

As pump 29, a pump of any known design can be used, designed to pump fluid into a well, for example, a cementing unit of the CA-320 brand, manufactured by Izhneftegaz LLC (Russian Federation, Republic of Udmurtia, Izhevsk).

Under the action of excessive pressure, the hollow rod 12, hermetically installed by means of sealing rings 20 inside the support pipe 1, together with the casing 11, with which it is connected by means of the fingers 10, begin to move downward, compressing the spring 19, which is supported from below in the upper end face of the rigid centralizer 17.

As a result of this, the casing 11 is lowered downward relative to the self-sealing cuff 8, which, by means of the upper 6 and lower 7 bushings, is in a fixed position on the outer surface of the support pipe 1, while the self-sealing cuff 8 comes out of the casing 11, and its collar is in the initial position the casing 11, begins to straighten and adhere to the inner wall of the column head 24.

The pressure in the support pipe 1 continues to rise, while the hollow rod 12 together with the fingers 10 and the casing 11 continue to move down the longitudinal through grooves 9 of the support pipe 1, while the collar of the self-sealing cuff 8 continues to straighten and fit more tightly to the inner wall of the column head 24 as the self-sealing cuff exits from the casing 11 (Fig. 2).

At a certain point, the lower end of the casing 11 abuts against the upper end of the outer cylindrical protrusion 16 of the support pipe 1 and the compression of the spring 19 is stopped, while the upper row 4 of radial channels of the support pipe 1 opens.

The outer cylindrical protrusion 16 of the support pipe 1 protects the spring 19 from breaking under the influence of excessive pressure, which is positively reflected in the reliability of the device.

As a result (Fig. 2), the hollow rod 12 is lower than the upper row 4 of radial channels of the housing 1 and creates a hydraulic connection between the inner space 30 of the support pipe 1 and the space 14 above the self-sealing sleeve 8 through the above upper row 4 of radial channels of the support pipe 1. As a result the pressure in the inner space of the column 30 of the support pipe 1 and the space 14 above the self-sealing cuff 8 is equalized.

Then, they continue to pump the process fluid into the support tube 1 and raise the pressure to the intended pressure of pressure testing of the preventer, for example, 25.0 MPa, while the generated overpressure will compress the self-sealing sleeve 8 previously pressed against the inner wall of the column head 24, and on the other the sides act on the dies 28 tightly compressing the support tube 1. The preventer 3 is held under the above pressure, for example, for 30 minutes, and a pressure drop of more than 5% is not allowed, i.e. at 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.

At the end of the crimping, the preventer 3 relieves the pressure by opening the valve 22 on the nozzle 23 of the column head 24 of the well, while the excess pressure in the space 14 above the self-sealing cuff 8 is reduced, and the casing 11 is returned to its original position by the spring force 19, compressing the collar of the self-sealing cuff 8 inward, while the self-sealing cuff 8 is inside the casing 1 (Figs. 1 and 2).

When removing the device from the column head 24 of the well, the process fluid freely flows from top to bottom from space 14 above the self-sealing sleeve 8 through the bottom row 5 of radial channels of the support pipe 1 through longitudinal channels 15 and channel 25 of the hollow rod 12 into the space 13 under the support pipe 1. This allows to lift the device from the column head 24 without overflow at the wellhead.

Due to the fact that the rubber cuff is made in the form of a self-sealing cuff 8, the reliability of the device at high pressures (25–35 MPa) increases, since with increasing excess pressure the self-sealing cuff 8 is pressed against the inner walls of the column head 24 of the well. This greatly reduces the likelihood of loss of tightness of the device during the 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 the reduction in the complexity of the device, since the proposed device is reusable, therefore, after each crimping of the preventer, there is no need, as described in the prototype, to disassemble, revise, and assemble it.

The environmental damage is reduced by eliminating the outflow of well fluid at the wellhead, since when the device is lowered, the fluid in the well flows freely from the bottom up from the space 13 under the support pipe 1 to the space 14 above the self-sealing sleeve 8 through the through longitudinal channels 15 of the hollow rod 12, and when lifting the device from the column head 24 of the well, the fluid flows in the opposite direction - from the space 14 above the self-sealing cuff 8 into the space 13 under the support pipe 1. Also, because of this, there is no need bridges each time after the device is lowered into the column head 24, i.e. Before pressure testing the preventer, fill the column head 24 of the well with process fluid.

The service life of the self-sealing sleeve 8 is increased due to reduced wear and damage, since it is in the casing during installation and removal of the device from the column head, and during crimping, when the self-sealing sleeve 8 is pressed against the inner walls of the column head 24, it is centered relative to the column head 24 of the well.

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;

- to exclude harm to the environment during the operation of the device;

- increase the life of the device.

Claims (1)

A device for crimping a preventer in a well, including a support pipe passing through a preventer body, a hollow rod installed in the support pipe and a rubber sleeve placed on the support pipe, characterized in that the support pipe is equipped with top and bottom rows of radial channels from the bottom, and moreover, on the support the upper and lower bushings are rigidly fixed to the pipe, between which a rubber cuff is installed, made in the form of a self-sealing cuff, while the support pipe is provided with through longitudinal grooves into which fingers are installed, which are connected on one side to a casing mounted on the outer surface of the housing under the lower sleeve, and on the other hand, with a hollow rod plugged from above placed inside the support pipe, and in the initial position, the hollow rod from above tightly overlaps the upper row of radial channels of the support pipe and from below the hollow rod hydraulically communicates the space under the support tube with the space above the self-sealing cuff by means of through longitudinal channels made in the hollow rod opposite the lower row p adial channels of the support pipe, and in the initial position, the self-sealing cuff is inside the casing, and in the working position the casing and the hollow stem have the possibility of axial limited movement along the through longitudinal grooves of the support pipe to the stop of the casing in the outer cylindrical protrusion made on the lower end of the support pipe, this hollow rod hermetically closes the lower row of radial channels of the support pipe, and the support pipe is equipped with a bottom centralizer, equipped with external overflow channels and bottom spring-loaded casing, and the outer diameter d _{1 of the} hard centralizer is larger than the outer diameter d _{2 of the} casing, in which the self-sealing cuff is in the initial position, while the upper end of the support pipe is hydraulically connected to the pump.

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