RU2788207C1 - Preventer pressure test stand - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry, in particular to devices for pressurizing a preventer in a well and/or in a test well of a production service base. The device for pressurizing the preventer in the well includes a support pipe passing through the preventer body. The outer surface of the support pipe is equipped with a closed curly groove. Opposite the shaped groove on the outer surface of the support tube, a collet with outwardly spring-loaded gripping elements and a guide pin is movably placed. The rubber cuff is placed on the support pipe. The support tube below the collet is equipped with upper and lower outer cylindrical recesses. On the upper outer cylindrical sample there is an upper sleeve, provided with a conical surface from the outside, tapering from bottom to top, and an upper rubber cuff. On the lower outer cylindrical sample there is a metal ring, a lower rubber cuff and a lower bushing with overflow channels. The lower bushing is rigidly fixed to the lower end of the support tube. The collet is directed downward by spring-loaded gripping elements, which are equipped with internal conical surfaces identical to the conical surface of the upper sleeve, with which they interact in the working position, after contact of the spring-loaded gripping elements of the collet with the joint of the well string coupling. On the outer surface of the support tube there is a closed shaped groove with alternating longitudinal short and long grooves. During the reciprocating movement of the collet relative to the support pipe, the guide pin alternately moves either into a short groove - the transport position, then into a long groove - the working position. The annulus of the well is hydraulically connected to the pump. A valve is installed at the upper end of the support pipe.

EFFECT: simplifying the design, increasing the reliability of the bench in operation, reducing labor intensity when working with the bench, as well as providing the ability to control the presence of fluid leaks during pressure testing of the preventer.

1 cl, 4 dwg

Description

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

A device for pressurizing a preventer in a well is known (patent RU No. 2719878, MPK E21V 33/03, publ. 04/23/2020), including a support pipe passing through the preventer body and a rubber cuff placed on the support pipe, while the rubber cuff is made in in the form of a figured elastic sleeve, provided on the outside with a petal seal, made from the inside in the form of an inverse 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 provided with a number of radial holes made opposite the seal from the inside under the action hydraulic pressure of a figured elastic sleeve, while the outer surface of the support pipe above the figured elastic sleeve is first equipped with a figured groove, and then with an external stepped annular selection, consisting of lower and upper stages, and the figured groove consists of longitudinal short and long sections, while opposite curly groove on n On the outer surface of the support tube, a spring-loaded outward collet with a guide pin placed in a shaped groove is movably placed, while the longitudinal short and long sections of the shaped groove are connected to each other by a closed figured section so that during axial reciprocating movement of the collet relative to the support tube, 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 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 stage of the outer stepped annular selection of the support pipe, moreover, the lower end of the support pipe is equipped inside with a knock-off valve, and below - with a rigid centralizer with external overflow channels, and in the initial position, the outer diameter d _{1 of} the rigid centralizer is larger than the outer diameter d _{2 of} the figured elastic sleeve.

The disadvantages of the device are:

- firstly, the complexity of the design, due to the large number of parts (shut-off valve, check valve, radial channels of the support pipe, etc.);

- secondly, low reliability in operation, associated with a high probability of jamming of the spring-loaded gripping elements of the collet in the lower and / or upper stages of the stepped ring selection during fixation in the coupling joint;

- thirdly, the low service life of the rubber cuff. This is due to the fact that it is made in the form of a figured elastic sleeve, in the lower part from the outside it is equipped with a petal seal, made with a gap from the inside in the form of an inverse cone, tapering from top to bottom and at high crimping pressures of 30-35 MPa, the figured elastic sleeve will burst or leaks will appear at the place of attachment of the sleeve to the support pipe;

- fourthly, the complexity of the application, since after each pressure test of the preventer, it is necessary to disassemble it to replace the knock-off valve, followed by assembly of the stand, which increases the cost of servicing the device during the pressure test of the preventer;

- fifthly, there is no possibility to control leaks through the rubber collar during preventer pressure testing, since during pressure testing the liquid is supplied to the support pipe, then if the rubber sleeve is not hermetically sealed, gaps in the annular space from top to bottom through the rubber sleeve are possible.

The closest in terms of technical essence and the achieved result is a bench for pressure preventer pressure testing on a well (patent RU No. 2719879, IPC E21V 33/03, publ. 04/23/2020), including a support pipe passing through the preventer body, a hollow rod installed in the support pipe a rubber cuff placed on the support pipe, while the outer surface of the support pipe is equipped with a closed curly groove, and above the closed curly groove it is equipped with a stepped annular selection, consisting of lower and upper steps, and the curly groove consists of longitudinal short and long sections, while opposite the curly groove In the groove on the outer surface of the support pipe, a collet with a guide pin is movably placed, while the collet is spring-loaded by the gripping elements outward and directed upwards, and the guide pin is placed in the figured groove, while the longitudinal short and long sections of the figured groove are interconnected by a closed figured section so that with axial reciprocating transfer when the collet is moved relative to the support tube, the guide pin will be located either in the longitudinal short section of the shaped groove - the transport position, in which the collet interacts with the lower step of the outer stepped annular selection of the support tube, then in the longitudinal long section of the shaped groove - the working position in which the collet interacts with the upper step of the outer stepped annular selection of the support pipe, and the lower part of the rubber cuff, made in the form of a hollow cylinder, is rigidly fixed to the lower part of the support pipe, while the upper part of the rubber cuff is put on the mandrel, rigidly fixed to the support pipe, while above the mandrel, but below the shaped groove, the support pipe is equipped with a number of radial holes, and opposite the mandrel it is equipped with through longitudinal grooves in which movable fingers are installed, which are connected to the mandrel on one side, and on the other side are connected to a hollow stem, which is equipped with a check valve from above and from below spring-loaded from the base pipes, moreover, in the transport position, the hollow rod hermetically covers a number of radial holes of the support pipe, while from below the hollow rod hydraulically communicates the spaces above and below the support pipe, and in the working position, the hollow rod has the possibility of axial limited movement down within the through longitudinal grooves of the support pipe up to opening a number of radial holes in the support pipe, wherein the support pipe below the rubber cuff is equipped with a spring centralizer, and the outer diameter d _{1 of} the spring centralizer is greater than the outer diameter d _{2 of} the rubber cuff in the transport position, while the upper end of the support pipe is hydraulically connected to the pump.

The disadvantages of the device are:

- firstly, the complexity of the design, due to the large number of parts (hollow rod, spring, spring centralizer, radial channels of the support pipe, sealing elements, etc.);

- secondly, low reliability in operation, associated with the presence of a compression spring, which, under alternating loads and frequent pressure testing of the preventer, especially at high pressure pressures of 30-35 MPa, can fail, which will lead to a breakdown of the bench as a whole. Also, there is a high probability of jamming of the spring-loaded gripping elements of the collet in the lower and/or upper steps of the stepped annular selection during fixation in the coupling joint. In addition, the hydraulic fit of the rubber cuff is less reliable than the mechanical one, since the mating parts must be tight, which requires a significant number of sealing rings on the mating surfaces;

- thirdly, the low service life of the rubber cuff associated with its wear and damage. This is due to the design of the collar cuff, which is planted using a hydraulically actuated mandrel, so if the rubber cuff is squeezed by the mandrel, it will lose its tightness. In addition, at high pressing pressures of 30-35 MPa, there is a high probability of loss of tightness of the rubber cuff;

- fourthly, the complexity of the application, since the packer is set hydraulically, then after each pressure test of the preventer, it is necessary to disassemble it, revise, assemble it, for the tightness of the sealing rings, which increases the cost of servicing the device during the pressure test of the preventer;

- fifthly, there is no possibility to control leaks through the rubber collar during preventer pressure testing, since during pressure testing the liquid is supplied to the support pipe, then if the rubber sleeve is not hermetically sealed, gaps in the annular space from top to bottom through the rubber sleeve are possible.

The technical objectives of the invention are to simplify the design, increase the reliability of the stand in operation, increase the service life of the stand, as well as reduce labor intensity when working with the stand and the ability to control the presence of fluid leaks during pressure testing of the preventer.

Technical problems are solved by a preventer pressure test bench, which includes a support pipe passing through the preventer body, the outer surface of the support pipe is equipped with a closed shaped groove, and opposite the shaped groove on the outer surface of the support pipe, a collet with outwardly spring-loaded gripping elements and a guide pin is movably placed, as well as rubber cuff placed on the support pipe.

What is new is that the support tube below the collet is equipped with upper and lower outer cylindrical recesses, on the upper outer cylindrical recess there is an upper sleeve, externally equipped with a conical surface, tapering from bottom to top and an upper rubber cuff, while on the lower outer cylindrical sample there is a metal ring, a lower rubber cuff and a lower sleeve with overflow channels, the lower sleeve being rigidly fixed to the lower end of the support pipe, while the collet is directed downward by spring-loaded gripping elements, while the gripping elements are equipped with internal conical surfaces identical to the conical surface of the upper sleeve with which they interact in working position, after contact of the spring-loaded gripping elements of the collet with the joint of the well string coupling, and on the outer surface of the support pipe there is a closed shaped groove with alternating longitudinal short and long grooves, while reciprocating When the collet moves relative to the support pipe, the guide pin alternately moves either into a short groove - the transport position, then into a long groove - the working position, while the annulus of the well is hydraulically connected to the pump, and a valve is installed at the upper end of the support pipe.

In FIG. Figure 1 schematically shows a stand for pressure testing of the preventer on the well in the transport position during the descent into the well.

In FIG. 2 - development of a curly groove.

In FIG. 3 and 4 schematically show the proposed stand for pressure testing of the preventer on the well in the working position.

The stand for pressure testing of the preventer includes a support pipe 1 (Fig. 1, 3, 4) passing through the body 2 of the preventer 3.

The outer surface of the support pipe 1 is equipped with a closed shaped groove 4 (Fig. 1-4), and opposite the shaped groove 4 on the outer surface of the support pipe 1, a collet 5 is movably placed (Fig. 1, 3, 4) with outwardly spring-loaded gripping elements 6 (for example , in the amount of 6 pieces) and with a guide pin 7 (Fig. 1-4).

The support pipe 1 below the collet is equipped with an upper 8 (Fig. 1, 3, 4) and a lower 9 external cylindrical samples.

On the upper outer cylindrical sample 8, there is an upper sleeve 10 provided with a conical surface 11 from the outside, tapering from the bottom upwards, and an upper rubber cuff 12.

On the lower outer cylindrical sample 9 there is a metal ring 13, a lower rubber cuff 14 and a lower sleeve 15 with overflow channels 16, which acts as a centralizer during the operation of the device.

Upper 12 and lower 14 rubber cuffs are made of different hardness. For example, the lower rubber cuff is soft and has a hardness of 35-45 Shore. The upper rubber collar 12 is hard and has a Shore hardness of 70-90 conventional units.

Loads for compression of the upper 12 and lower 14 rubber cuffs, made in the form of a hollow cylinder, and their radial expansion is determined empirically.

The outer diameter d ₁ (Fig. 1) of the lower sleeve 15 (Fig. 1, 3, 4) with overflow channels 16 is 10 mm larger than the outer diameter d _{2 of} the first rubber cuff 12 and the outer diameter d _{3 of} the second rubber cuff 14 equal to each other: those. d ₁ > d ₂ = d ₃ in the transport position.

The lower sleeve 15 is rigidly fixed to the lower end of the support pipe 1.

Collet 5 spring-loaded gripping elements 6 is directed downwards.

The spring-loaded gripping elements 6 of the collet 5 are equipped with inner conical surfaces 17 (FIGS. 1, 3, 4) identical to the conical 11 surface of the upper sleeve 10 with which they interact in the working position.

The collet 5 with spring-loaded gripping elements 6 interacts in the working position with the joint 18 (Fig. 1, 3, 4) of the coupling 19 of the pipe string 20, while the inequality must be observed:

a < b,

where a is the height of the fixing part of the gripping element 6 (Fig. 1) of the collet 5, for example, 13 mm;

b is the height of the joint 18 of the coupling 19, for example, 18 mm.

The outer diameter d _{1 of} the lower sleeve 15 with overflow channels 16 is taken 6 mm less than the inner diameter of the pipe string 20. For example, if the inner diameter of the pipe string 20 is 150 mm, then d ₁ = 150 mm - 6 mm = 144 mm. Then the outer diameters of the upper 12 and lower 14 rubber cuffs will be equal to 144 - 10 mm = 134 mm.

Closed curly groove 4 (Fig. 2) is made with alternating longitudinal short 21 (Fig. 2) and 22 long grooves.

The guide pin 7 of the collet 5 is placed in a closed shaped groove 4 (see Figure 2) so that when the collet 5 reciprocates with spring-loaded gripping elements 6 relative to the body 1, the guide pin 7 alternately moves, then in a short longitudinal groove 21 - transport position, then into a long longitudinal groove 22 - working position.

Stand for pressure testing of the preventer on the well works as follows.

The stand is assembled as shown in Fig. 1, while the guide pin 7 is in the transport position (see Fig. 2) and is placed on a short longitudinal groove 21 of the closed shaped groove 4.

To carry out round-trip operations during the operation of the stand, a lifting structure is used, if in the field, then a lifting unit is used, for example, APRS-40, if on the basis of production maintenance, then a beam crane.

Lifting structure support pipe 1 in assembled form (see Fig. 1) using the elevator 23 (Fig. 1, 3, 4) through the body 2 of the preventer 3 with the valve 24 open (Fig. 1, 3, 4) of the pipe 25 is lowered into column head 26 and further into the pipe string 20, while the outer surfaces of the upper 12 and lower 14 rubber cuffs, due to the lower sleeve 15 with overflow channels 16 are not in contact with the inner walls of the pipe string 20 (Fig. 1).

The tubing string 20 may be a drill pipe, a casing pipe, and the like. In the process of descending into the pipe string 20, the support pipe 1 bypasses the liquid from the bottom up, while the lower sleeve 15 with overflow channels 16 centers the device relative to the axis of the pipe string 20.

The support pipe 1 is lowered into the well so that the collet 5 is below the sleeve 19 by 2-3 meters.

Raise the support pipe 1 up by about 1 meter and lower it again, as a result of which the guide pin 7 moves from the upper part of the short groove 21 to the upper part of the long groove 22 of the closed shaped groove 4 (see Fig. 2). This is because the spring-loaded gripping elements 6 with their outer surfaces (see Fig. 1) are in close contact with the inner walls of the pipe string 20, due to which the collet 5 with the spring-loaded gripping elements 6 remains stationary, and the support pipe 1 makes a reciprocal motion relative to it. - forward movement.

Then the support tube 1 begins to be lifted up, while the collet 5 with spring-loaded gripping elements 6 continue to remain stationary, due to the tight contact of the outer surfaces of the spring-loaded gripping elements 6 with the inner walls of the pipe 20 until the support pipe 1 rises up, while the guide pin 7 (see Fig. 2) will move from the upper part of the long groove 22 to its lower part.

At a certain moment, the conical surface 11 (see Fig. 3) of the upper sleeve 10 will come into contact with the inner conical surfaces 17 identical to it, which are provided with the spring-loaded gripping elements 6 of the collet 5.

The rise of the support pipe 1 is continued upward, while under the action of the load acting on the spring-loaded gripping elements 6 from below, due to the contact of the conical surface 11 of the upper sleeve 10 with the inner conical surfaces 17, which are provided with the spring-loaded gripping elements 6 of the collet 5, the spring-loaded gripping elements 6 move up until they hit the joint 18 of the sleeve 19 of the well, as evidenced by the appearance of the load on the weight indicator (not shown in Fig. 1-4).

Further work is carried out according to two options, depending on the pressure of the preventer pressure test.

First option. If it is necessary to pressurize the preventer to a pressure of up to 20.0 MPa

For example, the preventer must be pressurized to 19.0 MPa. To do this, with the help of a lifting unit or a crane-beam, the tension of the support pipe is increased upwards, for example, up to 2500 N (250 kg), while the lower sealing element of the rubber cuff 14 is packed due to the fact that the load from the collet 5 through the inner conical surfaces 17, spring-loaded gripping elements 6 is transferred to the conical surface 11 of the upper sleeve 10, which, in turn, by the upper sealing element with a rubber cuff 12 of greater hardness than the lower sealing element 14 and the metal ring 13 acts from above, compresses the aforementioned lower sealing element of the rubber cuff 14 (see Fig. 3 ), since the lower sleeve 15 is rigidly fixed to the lower end of the body 1. The lower sealing element 14 expands radially and presses tightly against the inner walls of the pipe string 20.

Second option. If it is necessary to pressurize the preventer to a pressure of up to 35.0 MPa

For example, a preventer must be pressurized to 30.0 MPa. To do this, using a lifting unit or a crane-beam, the tension of the support pipe 1 is increased upwards, for example, up to 5000 N (500 kg), while the lower sealing element of the rubber cuff 14 is first packed due to the fact that the load from the collet 5 through the inner conical surfaces of 17 spring-loaded gripping elements 6 is transmitted to the conical surface 11 of the upper sleeve 10, which, in turn, through the upper sealing element, the rubber cuff 12 of greater hardness than the lower sealing element, the rubber cuff 14 and the metal ring 13 acts from above, compresses the aforementioned lower sealing element, the rubber cuff 14 (under load 2500 N), since the lower sleeve 15 is rigidly fixed at the lower end of the body 1, and then, when the load reaches 5000 N, the load from the collet 5 through the inner conical surfaces 17 of the spring-loaded gripping elements 6 is transferred to the conical surface 11 of the upper sleeve 10, which in turn turn leads to compression of the upper sealing element, the rubber cuff 12 (at a load of 5000 N) (see Fig. four)

The lower 14 and upper 12 rubber cuffs sequentially and radially expand and tightly pressed against the inner walls of the pipe string 20.

Having completed the work according to the first or second option, the valve 24 of the nozzle 25 (the annulus of the well) is hydraulically tied with the pump 27 (Fig. 3), and the valve 28 is installed at the upper end of the support pipe 1 and opened. Close the dies 29 of the preventer 3 (see Fig. 3 and 4), so that they tightly cover the outer surface of the support pipe.

As the pump 27 can be used a pump of any known design, designed for pumping fluid into the well, for example cementing unit brand TsA-320, produced by Izhneftegaz LLC (Russian Federation, Republic of Udmurtia, Izhevsk).

For example, it is necessary to carry out work on the second option, i.e. pressurize the preventer to 30.0 MPa.

To do this, using a pumping unit through the open valve 24 of the pipe 25, liquid is injected into the annulus between the column head 26 and the support pipe 1 and the pressure is raised to the intended pressure of the preventer pressure test, for example, 30.0 MPa. Keep the preventer 3 under the above pressure, for example, for 30 minutes, and the pressure drop by more than 5% is not allowed, i.e. at the end of the pressing time, the overpressure must be at least 28.5 MPa. Thus, preventer 3 is pressure tested.

Preventers that failed the test (pressure pressure below 28.5 MPa) are sent for repair, and preventers that successfully passed the test (pressure pressure from 28.5 to 30.0 MPa) are sent to the well for further work.

In the process of holding the preventer for 30 minutes, the presence of fluid leaks along the support pipe through the open valve 28 is also monitored. Thus, it is possible to control the tightness of the fit of the upper 12 and lower 14 rubber cuffs in the pipe string 20. Liquid leakage control is not available in the prototype. In addition, in the proposed stand, in the event of liquid leakage through the valve 28, it is possible to seal the upper rubber cuff 12. For example, by increasing the tension load of the support pipe to 6000 (600 kg).

After the pressure test of the preventer 3 is completed, the excess pressure is released to atmospheric pressure in the annulus between the column head 26 and the support pipe 1 using a pump, i.e. above the top 12 and bottom 14 rubber cuffs.

Next, the rams 29 of the preventer 3 are opened and the preventer 3 is removed from the stand, after which the support pipe 1 is lowered approximately 1-2 meters down, while the rubber cuffs 12 and 14 are first depressurized, which return to their original position, and then the support pipe 1 is lowered down relative to the guide pin 7, which, like the collet 5, remains stationary, due to the fact that the spring-loaded gripping elements 6 are in the joint 18 of the coupling 19. In this case, the guide pin 7 (see Fig. 2) from the bottom of the long groove 22 moves to the top part of the short groove 21 of the closed shaped groove 4 in the direction of movement of the support pipe 1. In this case, the conical surface 11 of the upper sleeve 10 comes out of contact with the inner conical surfaces 17 of the spring-loaded gripping elements 6 of the collet 5 (see Fig. 1), after which the support pipe 1 freely removed from the column head 26.

In the proposed stand, in comparison with the prototype, the design of the stand is simplified, the number of parts is reduced, which reduces the cost of manufacturing the stand.

Reliability in operation is increased, since the design excludes: a compression spring and sealing rings that reduce the reliability of the stand (spring breakage and / or fluid leakage through surfaces mating with sealing rings). The landing of rubber cuffs is carried out mechanically due to the tension of the support pipe, and not hydraulically as in the prototype, which is much more reliable. Also, the possibility of jamming of the spring-loaded gripping elements of the collet during fixation in the joint of the coupling is excluded, since the lower and upper steps of the stepped ring selection are excluded from the design, made on the outer surface of the support pipe, and the spring-loaded gripping elements of the collet are directed downward.

Increases the service life of rubber cuffs made with different hardness before wear and / or damage. This is due to the fact that, depending on the required crimping pressure, either only the lower rubber cuff 14 works (at a preventer crimping pressure of up to 20 MPa), or the upper 12 and lower 14 rubber cuffs work simultaneously (at a preventer crimping pressure of up to 35 MPa). This allows you to use the rubber cuffs in a gentle mode, thereby significantly reducing the likelihood of their wear and / or damage.

The laboriousness of application is reduced, since the landing of rubber cuffs is carried out mechanically, and the absence of sealing rings does not require an audit for the tightness of the stand, which reduces the cost of maintenance during pressure testing of the preventer.

The preventer pressure test stand allows you to:

- to simplify the design of the stand;

- increase the reliability of the stand;

- increase the service life of the stand;

- reduce the cost of maintenance when carrying out work on pressure testing of the preventer;

- control the presence of fluid leaks during pressure testing of the preventer.

Claims (1)

A bench for pressure testing of a preventer, including a support pipe passing through the preventer body, the outer surface of the support pipe is equipped with a closed shaped groove, and opposite the shaped groove on the outer surface of the support pipe, a collet with gripping elements spring-loaded to the outside and with a guide pin, as well as a rubber cuff, is movably placed, located on the support tube, characterized in that the support tube below the collet is equipped with upper and lower outer cylindrical selections, on the upper outer cylindrical selection there is an upper bushing, provided with a conical surface from the outside, tapering upwards, and an upper rubber cuff, while on the lower outer cylindrical in the sample there is a metal ring, a lower rubber cuff and a lower sleeve with overflow channels, and the lower sleeve is rigidly fixed at the lower end of the support pipe, while the collet is directed downward by spring-loaded gripping elements, while the gripping elements are equipped with internal conical surfaces identical to the conical surface of the upper sleeve, with which they interact in the working position, after contact of the spring-loaded gripping elements of the collet with the joint of the well string coupling, and on the outer surface of the support pipe there is a closed shaped groove with alternating longitudinal short and long grooves, while In the reciprocating movement of the collet relative to the support pipe, the guide pin alternately moves either into a short groove - the transport position, then into a long groove - the working position, while the annulus of the well is hydraulically connected to the pump, and a valve is installed at the upper end of the support pipe.

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