RU2778499C1 - Stand for testing wellhead equipment - Google Patents

Abstract

FIELD: wellhead equipment testing.

SUBSTANCE: invention relates to the stands for testing wellhead equipment. The stand for testing wellhead equipment consists of a support pipe with a mechanical packer, a wellhead flange and a pipe holder with a sealing ring installed between them, tightened together by fastening the flanges. Also, the stand contains a pumping unit hydraulically connected to the annulus of the support pipe. The mechanical packer is made in the form of a body with a seal assembly installed on it, made in the form of a prefabricated collar, consisting of a set of alternating rubber and metal rings. The stand pipe consists of the lower and upper parts, connected to each other by a split coupling, consisting of the lower and upper parts. A seat is hermetically installed in the split coupling of the test tube, with which the sealing element hermetically interacts. The housing above the sealing element is equipped with an external annular stop, which limits the axial downward movement of the housing. The flanges are fastened in the form of studs with segment elements and nuts, and the number of studs with segment elements and nuts is from 2 to 12.

EFFECT: simplification of the design of the stand for testing wellhead equipment and improving the reliability of the stand.

1 cl, 2 dwg

Description

The invention relates to the oil industry, in particular to devices for auxiliary production for the purpose of pressure testing of wellhead equipment at a test well of a production service base.

A stand for pressure testing of wellhead well equipment is known (patent RU No. 2719879, publ. 04/23/2020), including a support pipe passing through the preventer body, a hollow rod installed in the support pipe and a rubber cuff placed on the support pipe, which is a sealing element of a mechanical packer, with in this case, 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 on the outer surface of the support pipe is movably placed an outwardly spring-loaded collet of a mechanical packer with a guide pin placed in a shaped groove, while the longitudinal short and long sections of the shaped groove are interconnected by a closed figured section so that during axial reciprocating movement of the collet relative to the support pipe, the guide pin t 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 pipe, then in the longitudinal long section of the shaped groove - the working position in which the collet interacts with the upper stage of the external stepped annular selection support pipe, and the lower part of the rubber cuff, made in the form of a hollow cylinder, is rigidly fixed to the bottom of the support pipe, while the upper part of the rubber cuff is put on the mandrel of a mechanical packer, rigidly fixed to the support pipe, while above the mandrel, but below the figured 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 rod, which is equipped with a check valve from above and spring-loaded from the support pipe from below , and in the transport position and 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 until the row of radial holes of the support pipe opens pipes, and 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 stand are:

- firstly, the complexity of the design of the mechanical packer (rubber cuff, mandrel, collet), due to the large number of components and parts;

- secondly, the low reliability of the stand, due to the high probability of failure in the operation of the mechanical packer collet during axial reciprocating movement of the collet relative to the support pipe (when the packer is transferred from the transport position to the working position within the curly groove) and, as a result, the impossibility of landing mechanical packer;

- thirdly, the complexity of manufacturing the stand (shaped groove on the support pipe), due to the large number of technically complex parts, which leads to an increase in the cost of the structure as a whole and, as a result, its high cost;

- fourthly, the duration and laboriousness of the stand assembly when testing the wellhead equipment. This is due to the fact that the fastening of the flanges, which tightens the wellhead flange and the pipe holder, is made in the form of studs and nuts. In this connection, when fastening, it is necessary to screw two nuts on each stud (top and bottom) and tighten the fastening with two wrenches, which is time-consuming and laborious.

The closest is the bench for pressure testing of wellhead equipment, consisting of a support pipe with a mechanical packer, a wellhead flange and a pipe holder, with a sealing ring installed between them, flanges tightened together by fastening, as well as a pumping unit hydraulically connected to the annulus of the support pipe (patent RU No. 2708748, published 12/11/2019). The pipe hanger and the wellhead flange are pulled together by fastening flanges made in the form of studs and nuts, each stud is equipped with two nuts (top and bottom). The support pipe passes through the body of the pipe holder, the lower and upper rubber cuffs with a washer between them, the support and clamping plates, a hollow rod installed in the support pipe, designed to compress the rubber cuffs. An external cylindrical recess is made on the support pipe, in which a support plate is installed from the bottom up, made from below under a cone, tapering from top to bottom, and from above the support plate is made under an inverse cone, tapering from bottom to top, a lower rubber collar, a washer, an upper rubber collar and a clamping plate , while the inner diameter of the lower rubber cuff is larger than the inner diameter of the upper rubber cuff, and in the transport position, the reverse cone of the support plate interacts from above with the lower rubber cuff, and the upper ends of the support and clamping plates interact with the ends of the outer cylindrical sample, and in the support pipe opposite the clamping plate, a vertical through groove is made in which a pin is installed, while the pin is rigidly fixed on one side in the clamping plate, and on the other hand in the hollow stem with the possibility of limited movement within the vertical through groove in the working position, while the hollow stem is equipped with seat for the locking element dropped into the branch pipe, moreover, the support and clamping plates are equipped with conical chamfers for rubber cuffs, which prevent the rubber cuffs from leaking behind the support and clamping plates when they are packed in the well (in the bench pipe), while the support pipe below the support disc is equipped with a mechanical anchor with a guide pin placed in a shaped groove made on the outer surface of the support pipe in the form of interconnected horizontal and vertical grooves, while the mechanical anchor has the ability to move radially and axially within the shaped groove, while the upper end of the support pipe and the annulus well space is hydraulically tied with a pump.

The disadvantages of the stand are:

- firstly, the complexity of the design of the mechanical packer, due to the large number of components and parts;

- secondly, the low reliability of the stand operation, due to the high probability of failure in the operation of the mechanical anchor, which has the ability to move radially and axially within the figured groove and, as a result, the mechanical packer cannot be set in the well (bench pipe);

- thirdly, the complexity of manufacturing the stand (shaped groove on the support pipe), due to the large number of technically complex parts, which leads to an increase in the cost of the structure as a whole and, as a result, its high cost;

- fourthly, the duration and laboriousness of the stand assembly when testing the wellhead equipment. This is due to the fact that the fastening of the flanges, which tightens the wellhead flange and the pipe hanger, is made in the form of studs and nuts. In this connection, when fastening, it is necessary to screw two nuts on each stud (top and bottom) and tighten the fastening with two wrenches, which is time-consuming and laborious.

The technical objectives of the invention are to simplify the design of the stand for testing wellhead well equipment, increase the reliability of the stand, reduce its metal consumption and cost, as well as reduce the duration and complexity of assembling the stand when testing wellhead equipment.

Technical problems are solved by a bench for testing wellhead well equipment, consisting of a support pipe with a mechanical packer, a wellhead flange and a pipe hanger, with a sealing ring installed between them, flanges tied together by fastening, and a pumping unit hydraulically connected to the annulus of the support pipe.

What is new is that the mechanical packer is made in the form of a body with a sealing unit installed on it, made in the form of a prefabricated collar, consisting of a set of alternating rubber and metal rings, while the bench pipe consists of the lower and upper parts, interconnected by a detachable coupling consisting of from the lower and upper parts, while a seat is hermetically installed in the split coupling of the bench pipe, with which the sealing element hermetically interacts, and the body above the sealing element is equipped with an external annular stop that limits the axial movement of the body down, and the flanges are fastened in the form of studs with segment elements and nuts, and the number of studs with segment elements and nuts is from 2 to 12.

In FIG. 1 shows a bench for testing wellhead equipment.

In FIG. 2 shows a bottom view of the flange mounting.

The stand for testing wellhead equipment consists of a support pipe 1 (Fig. 1) with a mechanical packer consisting of a housing 2 and a seal assembly 3 installed on the outer surface of the casing 2. The seal assembly 3 is made in the form of a prefabricated cuff consisting of alternating rubber 4 and metal 5 rings.

The split coupling consists of a lower part 6' and an upper part 6". The bench pipe consists of a lower part 7' and an upper part 7" (Fig. 1, 2).

A stepped seat 8 (Fig. 1) is hermetically installed in the standpipe coupler, with which the seal assembly 3 hermetically interacts. The body 2 above the seal assembly 3 is equipped with an external annular stop 9, which limits the axial movement of the body 2 downwards. The support pipe 1 above the body 2 is equipped with radial holes 10.

Also, the stand contains a wellhead flange 11 (Fig. 1, 2) and a pipe holder 12 (Fig. 1), with a sealing ring 13 installed between them, as well as fastening flanges, consisting of studs 14 (Fig. 1, 2) with segment elements 15 and nuts 16 (Fig. 1), the number of each position (15; 16) is from 2 to 12.

Produce assembly stand for testing wellhead well equipment.

Assemble the bottom of the stand.

First, the lower part 6' of the split coupling is screwed onto the upper end of the lower part of the bench pipe 7' (see Fig. 1). Next, an annular sealing element is installed on the upper end of the lower part of the bench pipe 7' (in Fig. 1 it is shown conventionally). The stepped seat 8 is then placed in the lower part of the bench tube 7', with the outer step of the stepped seat 8 acting on the sealing element.

Next, screw the upper part of the 6" coupler onto the lower end of the upper part of the bench pipe 7". Then, an annular sealing element is installed on the upper stage of the stepped seat 8 (in Fig. 1 it is shown conventionally). After that, the split coupling is mounted. To do this, the upper part of the 6" split coupling with the upper part of the test tube 7" is screwed onto the fixed lower part 6' of the split coupling with the lower part of the test tube 7'.

Further, in the bench pipe (7' and 7") (see Fig. 2), a support pipe 1 is lowered with a mechanical packer consisting of a body 2 and a seal assembly 3 installed on the outer surface of the body 2.

The descent of the support pipe 1 into the bench pipe (7' and 7") is continued until the body 2 with its outer annular stop 9 rests against the stepped seat 8, while the sealing element 3, made in the form of a prefabricated cuff, consisting of alternating rubber 4 and metal rings 5 hermetically enters the stepped seat 8, installed in the split coupling.Next, the upper part of the stand is assembled.

As indicated above, as the wellhead equipment, flanges are used, consisting of studs 14 (Fig. 1, 2) with segment elements 15 and nuts 16 (Fig. 1), the number of each position (15; 16) is from 2 to 12.

1. Determining the installation time.

For example, the fastening of the flanges consists of 4 studs 14 (see Fig. 1 and 2) with segment elements 15 and four nuts 16.

Start the stopwatch and assemble the mount. To do this, insert the stud 14 with the segment element 15 into the aligned holes of the wellhead flange 11 and the pipe holder 12 from below. Turn the segment element 15 with an inner radius towards the central axis of the wellhead flange 11. flange 11 and pipe holder 12 the remaining five studs 14 with segment elements 15 by screwing nuts 16. Next, alternately tighten nuts 16 with a hand wrench. Stop stopwatch. Fix the result.

2. Determination of the tightness of the flange connection (pipe holder) when using wellhead downhole equipment - fixing the flanges, as indicated above, consisting of 4 studs 14 (see Fig. 1 and 2) with segment elements 15 and four nuts 16.

Tie the pump unit 17 (Fig. 1) through the side outlet 18 of the bench pipe 7 "with the annulus 19 (Fig. 1) of the support pipe 1. Fill the annulus 19 and the interior of the support pipe 1 (thanks to the radial holes 10) until the liquid exits through the upper end of the support pipe 1. Close the pipe valve 20 (Fig. 1) at the upper end of the support pipe 1. Using the pump unit 17, raise the hydraulic pressure of the liquid in the annulus 19, for example, up to 21.0 MPa according to the pressure gauge 21 (Fig. 1) pump unit 17.

Pressurize the fastening of the flanges by holding for 15 minutes (according to paragraph 342 of the Federal norms and rules in the field of industrial safety "Safety rules in the oil and gas industry" Order of Rostekhnadzor dated December 15, 2020 No. 534 FNP in the field of industrial safety dated December 15, 2020 N534). Turn off the pump unit 17, release the hydraulic pressure in the annulus 19 to zero. Dismantle the equipment in reverse order. Fix the result.

3. Determination of the dismantling time.

Start the stopwatch and disassemble the flange mounting. To do this, alternately loosen six nuts 16 with a hand wrench and unscrew the nuts 16 from the studs 14. Remove the studs 14 with segment elements 15 from the aligned holes of the wellhead flange 11 and the pipe holder 12. Stop the stopwatch. Fix the result.

A similar sequence of work with fastening flanges consisting of 2 to 12 studs with segment elements and nuts to them.

Thanks to the proposed design of the mechanical packer, made in the form of a body with a seal assembly installed in the seat of the standpipe split coupling, the design of the stand is simplified.

The absence of a figured groove on the support tube makes it possible to reduce the cost of manufacturing the support tube, in addition, the number of technically difficult parts to manufacture is reduced, which makes it possible to reduce the metal consumption. All this leads to a reduction in the cost of manufacturing individual parts of the stand, and in general to a decrease in the cost of manufacturing the stand.

The proposed design of the mechanical packer, made in the form of a housing with a seal assembly installed on it, hermetically placed in the stepped seat of the split coupling, eliminates the need for a mechanical anchor in the design of the bench, which guarantees a secure fit of the mechanical packer in the bench pipe, and this increases the reliability of the bench in in general.

The duration and laboriousness of the assembly of the stand is reduced when testing the wellhead equipment. This is due to the fact that the fastening of the flanges, which tightens the wellhead flange and the pipe holder, is made in the form of studs with segment elements and nuts, for example, 6 studs with segment elements and 6 nuts are used, while only one nut is screwed onto the stud and one wrench is used. , while the segment elements of the studs contract, i.e. are locked together, which eliminates the rotation of the studs while tightening the nuts with a wrench.

Stand for testing wellhead equipment allows you to:

- to simplify the design of the stand for testing wellhead equipment;

- increase the reliability of the stand;

- reduce metal consumption and cost;

- reduce the duration and laboriousness of the stand assembly when testing the wellhead equipment.

Claims (1)

Stand for testing wellhead well equipment, consisting of a support pipe with a mechanical packer, a wellhead flange and a pipe holder, with a sealing ring installed between them, flanges tightened together, as well as a pumping unit hydraulically connected to the annulus of the support pipe, characterized in that the mechanical packer is made in the form of a body with a sealing unit installed on it, made in the form of a prefabricated collar, consisting of a set of alternating rubber and metal rings, while the bench pipe consists of the lower and upper parts, interconnected by a split coupling, consisting of the lower and upper parts, while a seat is hermetically installed in the split coupling of the test tube, with which the sealing element hermetically interacts, and the body above the sealing element is equipped with an external annular stop that limits the axial movement of the body down, and the flanges are fastened in the form of studs with segmented elements elements and nuts, and the number of studs with segment elements and nuts is from 2 to 12.

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