RU2279537C1 - Device for flow string pressure-testing - Google Patents

Abstract

FIELD: mining, particularly devices for flow string pressure-testing in wells.

SUBSTANCE: device comprises high-pressure testing valve, anchoring unit and sealing unit. Hollow body of pressure-testing valve includes movable and fixed parts to be inserted in sealing unit. Annular spacer is created on movable part of hollow body. Additional sealing means of seating mechanism is arranged from the first side of annular spacer. The additional sealing means is made as collar of L-shaped section having opened end facing high-pressure cavity and provided with limiting case. Main packing gland is installed from the second side of annular spacer. The main packing gland is brought into contact with fixed hollow body part, which may be located on anchoring unit seat. High-pressure testing valve is provided with unloading valve formed as kinematic pair including rod and piston and provided with sealed coupler. Device comprises fixing mechanism, which retains unloading valve in its opened position.

EFFECT: simplified structure and increased reliability.

5 dwg

Description

The invention relates to the mining industry, and in particular to devices for crimping a string of tubing in a well.

Analysis of the existing level showed the following: a device is known for blocking a tubing string containing a body with longitudinal channels, in which there is a chamber with a mesh dividing the chamber into two parts, one of which is filled with a substance soluble in the produced fluid, a spring-loaded rod, a cone, and sealing elements and a retainer (see AS No. 933950 dated July 18, 1980, according to class E 21 B 34/10, publ. No. 21, 1982). The device through the lubricator descends into the well under its own weight to the location of the stoppipe and sits on its conical chamfer, and then a latch and a seal are introduced into the axial channel of the stoppipe with the formation of a tight contact between them.

A disadvantage of the known device is the lack of reliability of the design and inefficiency.

This is due to a number of reasons:

- the need for pre-installation in the composition of the tubing string of the stoppipe, which implies the rise to the surface of downhole equipment with the corresponding operation to kill the well; the use of a substance soluble in the reservoir fluid as a command source for ensuring pressure equalization above and below the device, after it is dissolved and removed from the upper part of the chamber, which is not a criterion for estimating the time for which pressure equalization the descent of the device is carried out in a well filled with liquid, and the dissolution of the substance occurs at different times, due to the composition of the liquid and different depths.

Thus, the device can be brought into a non-working state even during the descent to the stoppipe.

By design features, as well as by functional features of ensuring tightness, i.e. by preliminary forced landing of the sealant at its workplace in order to ensure tightness, the closest analogue (prototype) is a device for blocking the tubing string (see patent RU 2164587 C2 according to class E 21 B 34/06), containing a pipe string located in the well, a pressure test valve including a case with windows, an anchor assembly consisting of a rod, a set of clamps in the form of single-arm levers and a drive mechanism with a pusher associated with a core calibrated by shear ementom and installed in an axial housing bore for axial displacement. In addition, the device includes a fixation unit made of an elastic element, a sealing unit consisting of a sealant and a landing mechanism in the form of an expandable cone, rigidly connected to the rod.

The disadvantages of the known device include the complexity of the design and manufacturing technology, as well as the lack of reliability of the device in operation. The work of such parts as a collet, one-arm levers and grips is designed for the elasticity of their material, which is ensured by high expensive technology. The sealing element has a complex profile and is subjected to excessive deformation during operation, after which it must take the initial geometric shape due to internal elastic forces, while, as is known, the generally accepted material of the elastic element tends to solidify in the medium in which it works or with time loses plasticity. The presence of various kinds of debris in the process fluid indicates that it is possible that this debris enters the working bodies of the device, which are so unprotected that it ultimately leads to the failure of the device.

The technical task of the invention is to simplify the design and increase the reliability of the device.

This object is achieved in that a device for crimping a string of tubing containing a crimping valve, launched into the string of tubing in the well, consisting of a hollow body configured to silence its cavity and provided with a head under the catcher, anchoring unit located with the possibility of interaction with the junction of the tubing string at the lower end of the test interval, a sealing assembly consisting of a sealant and its seating mechanism, It is realized that the hollow body of the crimping valve consists of the movable and fixed parts included in the sealing assembly, on the movable part of the hollow body there is provided an integral annular separator, on one side of which there is an auxiliary seal of the landing mechanism in the form of an L-shaped cuff, open end which faces the high-pressure cavity and is equipped with a restrictive casing, and on the other hand, the main stuffing box seal in contact with the fixed part of the hollow pressure housing a flap valve made with the possibility of landing in the saddle of the anchor assembly mounted at the junction of the tubing string, the crimping valve is equipped with a pressure relief valve made in the form of a kinematic rod-cylinder pair with a sealed connector, the rod of which is central and radial, discharging holes located above the level of the sealed connector are provided on the transitional upper section of the movable part of the crimping valve body, and a cylinder connected to the centralizer and the head d catcher, seated on the rod through the compression spring, and introduced into the structure fixing the discharge valve mechanism in its open position.

Figure 1 shows a longitudinal section of a device for crimping tubing (hereinafter - the device) in the crimping position; figure 2 is a longitudinal section of the device in position before removing it from the tested string of tubing; figure 3 is a remote section A in figure 1; figure 4 is a view along arrow B in figure 1; figure 5 is a section along the plane indicated in figure 4.

The device comprises a pressure testing valve, which is launched into the tubing string in the well. The hollow body of the pressure testing valve consists of a movable 1 (Fig. 1) and a fixed 2 parts included in the sealing assembly. On the movable part 1 of the hollow body there is provided at the same time an annular separator 3, on one side of which an auxiliary seal 4 of the landing gear is installed in the form of an L-shaped cuff, the open end of which faces the high-pressure cavity and is equipped with a restrictive casing 5 that protects the seal 4 from damage and its eversion when removing from the tubing string. On the other side of the annular separator 3, there is a main stuffing box seal 6 in contact with the fixed part 2 of the hollow body of the pressure testing valve, adapted to fit into the saddle 7 of the anchor assembly, mounted at the junction of the tubing string 8. The auxiliary seal 4 is fixed on the movable part of the hollow case 1 using the rod 9 through the restrictive casing 5 and the installation sleeve 10, and the main seal 6 - nuts 11 through the fixed part of the hollow body 2 with the centralizer 12.

The pressure testing valve is equipped with an unloading valve made in the form of a kinematic pair "rod-cylinder", while the rod 9 (figure 1) is provided on the transitional section of the movable part of the hollow body 1 of the pressure valve, and the cylinder 13 is connected to a sleeve 14 ending in a head 15 under a catcher (not shown) with a centralizer 16, and is seated on the rod 9 through a compression spring 17, installed using nuts 18, and the restrictive sleeve 19, which determines the stroke of the discharge valve. The kinematic pair of the rod-cylinder is connected by a sealing connector provided with a radial 20 (Fig. 3) and an end 21 of the sealing rings, and in the rod 9 there is a central hole 22, in communication with a similar hole 23 in the movable part of the hollow body of the crimping valve on one side, and on the other hand, with radial discharge openings 24 located above the level of the sealing connector of the kinematic rod-cylinder pair.

The design introduced a mechanism for fixing the discharge valve in its open position, consisting, for example, of two lever stoppers 25 (Figs. 3, 4) mounted on a hinge 26 in diametrically opposed grooves 27 provided at the lower end of the rod 9. The upper end of the lever stops 25 is pressed against the outer surface of the cylinder 13 by means of a compression spring 28 integrated at the lower end of the lever stop 25 on the other side of the hinge 26. Alternatively, the compression spring 28 can be replaced by a bracelet spring or an elastic blue ring YETİK (P.I.Orlov. Basics of designing. Moscow, "Engineering", 1977, book 3, page 93) that cover the upper ends of the operating lever 25 stops, pressing them to the cylinder 13.

In the absence of a locking mechanism, the discharge valve is between two opposing forces - the force of the compression spring 17 is directed to close, and the extracting force applied to the head 15 is directed to open the discharge valve. When the device is removed from the tubing string at the moment the sealing unit passes through the pipe joints, resistance arises, which leads to an increase in the extraction force and the opening of the discharge valve and vice versa. So, in the process of removing the crimping device, the discharge valve then opens, then closes, being in an intermediate position, which leads to a slowdown in fluid flow, premature failure of the sealing elements 4, 6, 20, 21, to complicate the operation of the extraction winch, while how the fixation mechanism eliminates these disadvantages.

The device operates as follows. In the initial position, the unloading valve is closed (see callout A in Fig. 3), the device is inserted into the tubing string 8 (Fig. 1) and delivered to the seat 7 by pumping the test fluid using a pump unit (not shown). When creating pressure in the tubing string, the open end face of the auxiliary seal 4, located below the restrictive casing 5, is distributed, creating a tightness, and moves together with the moving part 1 of the hollow body down relative to its fixed part 2, which is seated in the seat 7. The main stuffing box seal 6 and at the same time the pressure testing of the tubing string 8 under test pressure is performed, as shown in figure 1.

After crimping, the device is removed at the wellhead with a reverse fluid flow. On injection wells with high throttle response, the device is removed with a special winch with a rope, at the end of which a catcher (not shown) is mounted under the head 15 (figure 2). When creating a tightness on the rope, the cylinder 13, overcoming the force of the spring 17, is lifted by the stroke of the discharge valve and is fixed in the open position by the stoppers 25 due to the action of compression springs 28 (Fig. 3) through the hinge 26. At the same time, the radial discharge openings 24 and the liquid located above the discharge valve under high pressure flows through the openings 24, 22 into the subvalvular cavity, comparing the pressure in them, which takes place along the entire extraction path. Before removing the pressure test valve is unloaded and its seals 4, 6 take the initial position shown in figure 2. After removal, the device is subjected to technical inspection, the integrity of the sealing elements is checked, which in case of damage are replaced with new ones, and the device is used again, etc.

A device with a mechanism for fixing the discharge valve in its open position ensures stable operation with increased quality and extends the life of the equipment used.

Claims (1)

A device for crimping a tubing string containing a crimping valve for starting a tubing string in a well, consisting of a housing configured to silence its cavity and provided with a head for a trap, an anchor assembly located to interact with the junction of the tubing string -compressor pipes at the lower end of the test interval, a sealing assembly consisting of a seal and a seating mechanism, characterized in that the hollow body of the test valve consists of the movable and fixed parts included in the sealing assembly, on the movable part of the hollow body there is provided at the same time an annular separator, on one side of which an auxiliary seal of the landing mechanism is installed in the form of an L-shaped cuff, the open end of which faces the high-pressure cavity and is equipped with restrictive casing, and on the other hand, the main stuffing box seal in contact with the fixed part of the hollow body of the crimping valve, made with the possibility of ki into the saddle of the anchor assembly, mounted at the junction of the tubing string, while the pressure testing valve is equipped with an unloading valve made in the form of a kinematic pair “rod-cylinder” with a sealed connector, the rod of which with central and radial discharge openings located above the level of the sealed connector it is provided on the transitional upper section of the moving part of the pressure test valve body, and the cylinder connected to the centralizer and the head for the catcher is seated on the rod through the compression spring, p We introduced into the design a mechanism for fixing the discharge valve in its open position.

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