RU2805701C1 - Method for installing preventer on support flange of wellhead assembly and constant tripping out two-lift arrangement of downhole equipment from well and device for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: methods intended for sealing the mouth of oil and gas wells using a preventer during constant tripping out a two-lift arrangement of downhole equipment from a well. A method for installing a preventer on the support flange of a wellhead assembly and constant tripping out a two-lift arrangement of downhole equipment from a well, including assembling the equipment and installing a ram preventer on the support flange of the wellhead assembly. Preliminarily install the coil between the lower flange of the preventer and the pipe holder flange. The coil is secured hermetically with a pin connection with the coil flange to the bottom flange of the preventer, and to the pipe holder flange with the coil pipe using a sealed threaded connection. A long string of pipes with downhole equipment is tripped out the well. Upon completion of lifting operations with a long pipe string, unscrew the fastening of the coil with the lower flange of the preventer and dismantle the preventer. The short string of pipes is tripped out after dismantling the pipe holder flange from the wellhead valve and sealing the ring onto the bottom flange of the preventer using a pin connection. Then the preventer is mounted together with the ring on the wellhead valve flange hermetically using a pin connection. Then a short string of pipes with downhole equipment is tripped out. If showings of oil, gas and water occur, a shut-off assembly is installed in the preventer, consisting of a sub, a branch pipe and a ball valve, which prevents release when showings of oil, gas and water occur.

EFFECT: simplifying the procedure for installing a preventer on the support flange of a wellhead valve and sequentially lifting a two-lift arrangement of downhole equipment from a well, expanding the functionality of the method and device, as well as reducing the duration of installation and dismantling of the preventer at the wellhead.

3 cl, 3 dwg

Description

The invention relates to methods intended for sealing the mouth of oil and gas wells using a preventer during sequential lifting of a two-lift arrangement of downhole equipment from a well.

There is a known method of installing a blowout ram preventer on the support flange of the wellhead valve, which includes hermetically fastening the preventer with the lower flange on the support flange of the wellhead valve (patent RU No. 2214499, published 10.20.2003).

The disadvantages of this method are:

- firstly, the complexity of the technology for implementing the method, since to extract a long string of pipes from a well it is necessary to use special equipment together with a preventer;

- secondly, the limited functionality of the method, since there is no shut-off arrangement, therefore it is necessary to replace pipe rams at the wellhead, depending on the size of the pipe string

- thirdly, the long duration of installation and dismantling of the preventer at the wellhead. This is due to the need to replace the preventer pipe rams when removing two columns of different sizes, for example 48 and 60 mm.

- fourthly, the high cost of work when implementing this method due to the need to manufacture special equipment for the preventer in order to extract a long pipe string, as well as high labor costs associated with dismantling the preventer from the wellhead to replace pipe rams for the required standard size of the pipe string .

A device is known for the method of installing a blowout ram preventer on the support flange of the wellhead valve, including a preventer installed on the support flange of the wellhead valve (patent RU No. 2214499, published 10/20/2003).

The disadvantages of the device are:

- firstly, it is impossible to block the internal cross-section and strings of pipes during hoisting operations (HWO) in the event of oil and gas water shows (OGWS);

- secondly, the difficulty of removing a long string of pipes due to the need to manufacture special devices for connecting or gripping a long string of pipes.

The closest in technical essence and achieved result is the method of installing a preventer with a replaceable ring on the support flange of a wellhead valve, including assembling equipment and installing a ram preventer (RU patent No. 2724695, published 06.25.2020). First, lifting lugs are installed on the preventer body at an angle of 180° relative to each other and offset relative to each other in the vertical plane, a preventer with minimal connecting and sealing dimensions of the lower flange corresponding to the supporting flange of the wellhead is selected, the lower flange of the preventer is hermetically connected to a replaceable ring of a larger standard size than the lower flange, but corresponding to the dimensions of the wellhead support flange, then the preventer with a replaceable ring is lifted by lifting eyes with an inclination angle corresponding to the inclination angle of the support flange of a well with an inclined mouth and is hermetically fastened on the wellhead support flange, while the replaceable the ring is made with connecting and sealing dimensions equal to the standard sizes of the supporting flanges of the wellhead fittings, and if it is necessary to attach the preventer to the supporting flange of the wellhead fittings of a different standard size, replace the installed replaceable ring with another replaceable ring corresponding to the supporting flange of the wellhead fittings to which the preventer will be attached.

The disadvantages of this method are:

- firstly, the complexity of the technology for implementing the method, since to extract a long string of pipes from a well it is necessary to use special equipment together with a preventer;

- secondly, the limited functionality of the method, since there is no shut-off arrangement, therefore it is necessary to replace pipe rams at the wellhead, depending on the size of the pipe string;

- thirdly, the long duration of installation and dismantling of the preventer at the wellhead. This is due to the need to replace the pipe rams of the preventer when removing two columns of different sizes, for example 48 and 60 mm;

- fourthly, the high cost of work when implementing this method due to the need to manufacture special equipment for the preventer in order to extract a long string of pipes, as well as high labor costs associated with the installation and dismantling of the preventer from the wellhead to replace pipe rams to the required standard size pipe columns.

A preventer with a replaceable ring is known, containing a preventer with a cast bottom flange that is sealed on the support flange of the wellhead fittings, while the preventer is equipped with a replaceable ring made of connecting and sealing dimensions corresponding to the dimensions of the support flange of the wellhead fittings to which the preventer is attached (patent RU No. 2724695 , published June 25, 2020). The bottom flange of the preventer is made with connecting and sealing dimensions corresponding to the minimum dimensions of the wellhead support flange, while the preventer is equipped with a replaceable ring made with connecting and sealing dimensions corresponding to the dimensions of the wellhead support flange on which the preventer is attached, and the replaceable ring is installed under the bottom flange with the possibility of hermetic fastening with a bolted connection, the lower flange of the preventer is equipped with a metal ring, and the connecting size of the lower flange corresponds to the center-to-center diameter of the bolted connection made in a replaceable ring; lifting lugs are rigidly fixed to the preventer body with a height offset relative to each other with the possibility of installing the preventer at the wellhead inclined well.

The disadvantages of the device are:

- firstly, it is impossible to block the internal cross-section of both pipe columns during the process of a special production process in the event of an NGVP, which can lead to various injuries to operating personnel;

- secondly, the difficulty of removing a long string of pipes due to the need to manufacture special devices for connecting or gripping a long string of pipes.

The technical results of the invention are the simplification of the technology for installing a preventer on the support flange of the wellhead valve and the sequential lifting of a two-lift arrangement of downhole equipment from the well, expanding the functionality of the method and device, as well as reducing the duration of installation and dismantling of the preventer at the wellhead and reducing the cost of work, expanding the arsenal of tools installation of a preventer on the supporting flange of the wellhead fittings and sequential lifting of a two-lift arrangement of downhole equipment from the well, simplifying the removal of a long pipe string from the well, as well as allowing the internal section of the pipe string to be blocked during the process of tripping in the event of an NGVP.

Technical results are achieved by installing a preventer on the support flange of the wellhead fittings and sequentially lifting a two-lift arrangement of downhole equipment from the well, including assembling the equipment and installing a ram preventer on the supporting flange of the wellhead fittings.

What is new is that a coil is pre-installed between the bottom flange of the preventer and the pipe holder flange, the coil is secured tightly with a hairpin connection with the coil flange to the bottom flange of the preventer, and to the pipe holder flange with the coil pipe using a sealed threaded connection, a long string of pipes is lifted from the well with downhole equipment, upon completion of lifting operations with a long string of pipes, unscrew the fastening of the coil with the lower flange of the preventer and dismantle the preventer; lifting of the short string of pipes is performed after dismantling the flange-pipe holder from the wellhead fittings flange and sealing the ring to the lower flange of the preventer using a pin connection, then the preventer is mounted together with the ring on the wellhead valve flange hermetically using a pin connection, then a short string of pipes with downhole equipment is lifted, if oil and gas shows occur, a shut-off arrangement is installed in the preventer, consisting of a sub, a branch pipe and a ball valve, which eliminates blowout in the event of oil and gas shows.

The technical result is achieved by a device for implementing a method for installing a preventer on the supporting flange of a wellhead valve and sequential lifting from a well of a two-lift arrangement of downhole equipment, containing a preventer with a cast lower flange, sealed on the supporting flange of the wellhead valve, while the preventer is equipped with a replaceable ring made of connecting and sealing dimensions corresponding to the dimensions of the wellhead support flange on which the preventer is attached.

What is new is that the preventer is additionally equipped with a shut-off assembly containing a sub, a branch pipe, a ball valve, and the preventer is also equipped with a coil connected to the wellhead pipe holder with a sealed threaded connection.

The preventer rams are sealed on the nozzle of the shut-off assembly.

In fig. Figure 1 shows a wellhead with two strings of pipes in a well.

In fig. Figure 1 shows a preventer when lifting a long pipe string.

In fig. Figure 2 shows a preventer when lifting a short pipe string.

A device for installing a preventer on the supporting flange of a wellhead valve and carrying out sequential lifting of two pipe strings from a well in an arrangement with downhole equipment consists of a preventer 1 (Fig. 2-3) with a cast lower flange 2 and a cast upper flange 3. The preventer 1 is secured by the lower flange 2 hermetically sealed:

- when lifting a long string of pipes 4 (Fig. 1, 2), on the pipe holder flange 5 through the coil 6 (Fig. 2);

- when lifting a short string of pipes 7 (Fig. 1-3), on the wellhead valve flange 8 (Fig. 1-3) through ring 9 (Fig. 3).

Coil 6 consists of a flange 10 (Fig. 2) and a pipe 11. The connecting and sealing dimensions of the flange 10 of the coil 6 correspond to the lower flange 2 of the preventer 1, and the pipe 11 is connected through a sealed threaded connection with the pipe holder flange 5. The flange 10 of the coil 6 is attached to the lower flange 2 of the preventer 1 using studs and nuts (shown conditionally in Fig. 1).

Ring 9 (Fig. 3) on the upper side has connecting and sealing dimensions corresponding to the lower flange 2 of the preventer 1, and on the lower side there are connecting and sealing dimensions corresponding to the wellhead valve flange 8. Ring 9 is attached to the lower flange 2 of the preventer 1 and to the flange wellhead fittings 8 using studs and nuts (shown conditionally in Fig. 3).

The preventer 1 is equipped with a shut-off arrangement 12 (Fig. 2-3) consisting of a pipe 13, connected from below by a sealed threaded connection to a sub 14 for fastening a string of pipes 4 or 7, and from the top with a ball valve 15.

When lifting a long string of pipes 4, the flange-pipe holder 5 is equipped with a plug 16 (Fig. 2), which is installed in the hole for the short string of pipes 7 in the flange and ensures the tightness of the internal cavity of the short string of pipes 7. The plug 16 is installed in the flange-pipe holder 5 with using a sealed threaded connection.

A preventer with a coil and ring works as follows.

An oil reservoir, for example, is developed by simultaneous injection and production, using a double-row pipe string. Water is pumped through one string of pipes, for example a string of tubing with a diameter of 60 mm, and through another string of pipes, for example a string of tubing with a diameter of 48 mm, oil is withdrawn, and the injection and withdrawal zones are separated by a packer (Fig. 1).

To implement the above-described technology during the operation and repair of a well, it is necessary to sequentially carry out lifting operations from the wellhead of pipe strings, tubing strings of two standard sizes 60 and 48 mm, for this purpose the design of the proposed preventer is used.

Before installing the preventer 1 on well 17 (Fig. 1-3) to lift a long pipe string 4 with diameter D (tubing column with a diameter of 60 mm), it is necessary to dismantle the upper piping of the well (not shown in Fig.) and instead of the pipe holder 18 (Fig. 1 ) install the adapter coil 6 (Fig. 2) with pipe 11 into the hole of the pipe holder flange 5 under the long column 4. Install plug 16 (Fig. 2) into the hole under the short pipe string 7. A metal ring 19 (Fig. 2) is installed on the flange 10 of the coil 6 in the corresponding annular groove.

Next, install preventer 1, for example PPShR-2F-152×21 with pipe rams to seal a column with a diameter of 73 mm. The preventer 1, by means of a lifting unit, is raised and centered relative to the flange 10 of the coil 6 and lowered down until the lower flange 2 of the preventer 1 fits onto the flange 10 of the coil 6. Next, the preventer 1 is attached to the coil 6 with a pin connection (shown in Fig. 2 conditionally). The tightness of the fastening is ensured metal ring 19.

After installing the preventer 1, lifting operations are carried out on a long string of pipes 4 (Fig. 2).

To lift a short column 7 with a diameter d (tubing columns with a diameter of 48 mm), it is necessary to dismantle the pipe holder flange 5. Equip the preventer 1 with a ring 9, for this purpose a metal ring 20 (Fig. 3) is installed in the corresponding annular groove on top in the ring 9, ring 9 centered relative to the lower flange 2 of the preventer 1 and attached to the lower flange 2 of the preventer 1 using a pin connection (shown conditionally in Fig. 3).

Next, install preventer 1 with pipe rams to seal a column with a diameter of 73 mm. The preventer 1 with a ring 9 attached to the lower flange 2 is lifted and centered relative to the wellhead flange 8 of the well 17 by means of a lifting unit, a metal ring 21 (Fig. 3) is installed in the corresponding annular groove in the wellhead flange 8 and the preventer 1 is lowered down until the lower ring 9 fits. to the wellhead flange 8. Next, the preventer 1 is attached to the wellhead flange 8 using a pin connection (shown in Fig. 3 conditionally). The tightness of the fastening is ensured by a metal ring 21.

After installing the preventer 1, lifting operations are carried out with a short string of pipes 7 (Fig. 3).

If an NGVP occurs with a long pipe string 4 with diameter D (tubing string with a diameter of 60 mm) or a short pipe string with diameter 7 d (tubing string with a diameter of 48 mm), at the wellhead, a shut-off assembly 12 is installed at the upper end of the pipe string, having a connecting thread on the nipple part sub 14 with a diameter corresponding to the diameter of the coupling thread of the pipe string being lifted (long pipe string with a diameter of 60 mm in accordance with GOST 633-80, short pipe string with a diameter of 48 mm in accordance with GOST 633-80). An elevator clamp 22 (Fig. 2-3) is installed on the upper flange 3 of the preventer 1 (Fig. 2-3), the shut-off assembly 12 is lowered together with the pipe string into the well 17 and suspended on the coupling 23 (Fig. 2-3) of the shut-off assembly. In this case, ball valve 15 should be in the “CLOSED” position.

Next, rotate the handwheels of the manual drives 24 (Fig. 2-3) and 25 clockwise by 5–6 turns, bring the pipe rams 26 and 27 together and clasp the outside of the pipe 13 of the shut-off arrangement with a diameter of 73 mm along the entire perimeter of its circumference, which appears under the pipe rams 26 and 27 during NGVP, the pressure of the well environment hermetically presses the elastic seals (not shown in the figure) of the pipe rams 26 and 27 to the outer surface of the nozzle 13. Thus, the space between the preventer 1 and the shut-off assembly 12 is sealed.

After the liquidation of the NGVP, i.e. after releasing the pressure in the well, open the preventer, depressurize the space between the preventer and the pipe 13 of the shut-off assembly 12 and restore the internal space of the pipe strings.

To do this, first open the preventer by rotating the steering wheels of manual drives 24 and 25 counterclockwise by 5-6 turns, and retract the pipe rams 26 and 27 until they stop.

Next, ball valve 15, shut-off arrangement 12, is turned to the “OPEN” position by turning the handle.

Having made sure that there is no release of NGVP along the pipe string, unscrew the shut-off arrangement 12 from the upper end of the pipe string and restore the internal space of the pipe string.

The device allows you to shut off the internal cross-section of both pipe columns during the process of a special fire when an NGVP occurs, and, as a result, ensure the safety of operating personnel.

Removal of a long string of pipes is simplified due to the need to manufacture special devices for connecting or gripping a long string of pipes by using a coil in the structure of the device.

The proposed design of a preventer with a spool and a ring allows for sequential lifting of two strings of pipes of different diameters with downhole equipment without disassembling the wellhead fittings and replacing the preventer rams.

The device allows:

- block the internal cross-section of both pipe columns when NGVP occurs;

- simplify the removal of a long string of pipes, reducing labor costs, which means saving money.

The method of installing the preventer 1 on the support flange 8 of the wellhead fittings and sequential lifting from the well of the two-lift arrangement of downhole equipment includes installing a coil 6 between the lower flange 2 of the preventer 1 and the pipe holder flange 5. The coil 6 is sealed with a pin connection by the flange 10 to the lower flange 2 of the preventer , and to the pipe holder flange 5 with pipe 11 using a sealed threaded connection. A long string of pipes 4 with downhole equipment is lifted from the well; upon completion of the lifting operations with the long string of pipes, the fastening of the reel 6 with the lower flange 2 of the preventer 1 is unscrewed and the preventer 1 is dismantled. To lift the short string of pipes, the flange-pipe holder 8 is removed from the wellhead valve flange 5, and on the bottom flange 2 of the preventer 1, a ring 9 is secured tightly using a hairpin connection and the preventer 1 together with the ring 9 is mounted on the wellhead valve flange 8 hermetically using a hairpin connection, then a short string of pipes with downhole equipment is lifted.

The technology for implementing the method is simplified, since a reel is used to extract a long string of pipes from the well.

The functionality of the method is expanded, since the proposed method uses a shut-off arrangement, so there is no need to replace pipe rams at the wellhead depending on the size of the pipe string.

The duration of installation and dismantling of the preventer at the wellhead is reduced. Since there is no need to replace the preventer pipe rams when removing two columns of different sizes, for example 48 and 60 mm.

The cost of work when implementing this method is reduced due to the lack of manufacturing special equipment for the preventer in order to extract a long pipe string (a reel is used), and the labor costs associated with the dismantling and installation of the preventer from the wellhead to replace pipe rams for the required standard size of the pipe string are also reduced. . The arsenal of means for installing a preventer on the supporting flange of the wellhead valve and sequentially lifting a two-lift arrangement of downhole equipment from the well is expanding.

The method allows:

- simplify the technology for implementing the method;

- expand the functionality of the method;

- reduce the duration of installation and dismantling of the preventer at the wellhead;

- reduce the cost of work when implementing this method.

Claims (2)

1. A method for installing a preventer on the supporting flange of the wellhead fittings and sequentially lifting a two-lift arrangement of downhole equipment from the well, including assembling the equipment and installing a ram preventer on the supporting flange of the wellhead fittings, characterized in that a coil is pre-installed between the lower flange of the preventer and the pipe holder flange, a coil they are secured tightly with a pin connection by the reel flange to the bottom flange of the preventer, and to the pipe holder flange by the reel pipe using a sealed threaded connection, a long string of pipes with downhole equipment is lifted from the well, and upon completion of lifting operations with the long string of pipes, the fastening of the reel with the lower flange is unscrewed preventer and dismantle the preventer, lifting the short pipe string is carried out after dismantling the pipe holder flange from the wellhead valve flange and sealing the ring onto the bottom flange of the preventer using a hairpin connection, then mounting the preventer together with the ring on the wellhead valve flange hermetically using a hairpin connection, then perform lifting a short string of pipes with downhole equipment; if oil and gas shows occur, a shut-off assembly is installed in the preventer, consisting of a sub, a branch pipe and a ball valve, which prevents blowout when oil and gas shows occur. 2. A device for implementing a method for installing a preventer on the supporting flange of a wellhead valve and sequential lifting from a well of a two-lift arrangement of downhole equipment, containing a preventer with a cast lower flange, sealed on the supporting flange of the wellhead valve, while the preventer is equipped with a replaceable ring made with a connecting and sealing dimensions corresponding to the dimensions of the wellhead support flange on which the preventer is attached, characterized in that the preventer is additionally equipped with a shut-off assembly containing a sub, a branch pipe, a ball valve, and the preventer is equipped with a coil connected to the wellhead pipe holder with a sealed threaded connection.