RU2285107C2 - Device for pipe string interval pressure-testing - Google Patents

Abstract

FIELD: mining, particularly devices for periodical production string interval pressure-testing inside well.

SUBSTANCE: device comprises pressure-testing valve to be lowered in pipe string. The valve has body, head for fishing tool receiving connected to valve body, anchoring unit with a number of driving retainers made as levers and sealing unit with compactor. Shoe made as tubular section is installed at lower end of pipe string to be pressure-tested. The tubular section defines length-limited inner annular space having diameter exceeding inner diameter of pipe string to be pressure-tested. Compactor is arranged between lower fixed and upper movable valve body parts. The lower and upper valve body parts are mutually spring-loaded and provided with outer facets. Anchoring unit includes upper and lower anchoring members serially arranged in lower fixed valve body part. Each anchoring member is provided with individual drive made as wedge with spring and is made as a pair of cooperating double-armed driving levers installed on common hinge and provided with lower anchoring ends. The lower anchoring ends correspondingly engage pipe string joint and the shoe.

EFFECT: simplified structure and increased operational reliability.

5 dwg

Description

The invention relates to the mining industry, and in particular to devices for periodically 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 latch (see AS No. 933950 dated July 18, 1980 according to class E 21 B 34/10, published in OB 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 unreliability 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 locking pipe, which implies the rise to the surface of downhole equipment with the corresponding operation to kill the well; using a substance soluble in the reservoir fluid as a command source to ensure 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 occurs, since 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, 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 connected to the core with a calibrated 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 it is known that the generally accepted material of the elastic element tends to solidify in the medium in which it works or loses over time plastic.

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.

The specified technical task is carried out by the fact that the device for interval testing of the pipe string in the well, comprising a pressure testing valve that is launched into the pipe string, including a body, a head for a catcher connected to the body, an anchor assembly with a set of drive clamps in the form of levers, a sealing assembly with a sealant, installed with the possibility of landing, made so that it contains mounted on the lower end of the test interval pipe string shoe in the form of a tubular section with a limited about the length of the inner annular cavity of a larger size than the inner diameter of the tested pipe string, the seal of the sealing assembly is located between the lower fixed and upper movable spring-loaded to each other, provided with an external chamfer, parts of the crimping valve body, and the anchoring assembly is made of sequentially located in the lower stationary part the case of the crimping valve of the upper and lower anchoring nodes, each of which is equipped with an individual drive in the form of a wedge with a spring and made in the form of a pair of two shoulders mounted on a common hinge with the possibility of interaction between the drive levers with the lower anchor ends for the junction of the pipe string and shoe, respectively.

Figure 1 shows a longitudinal section of the device in the descent into the pipe string before entering the shoe; figure 2 is a longitudinal section of the device in the anchor position for the shoe; figure 3 is a longitudinal section of the device in the anchor position for the junction of the pipe string; figure 4 is a longitudinal section of a crimping valve; figure 5 is a section of the crimping valve along the line aa in figure 4.

The device comprises a shoe 2 mounted on the lower end of the test interval of the pipe string 1 (Fig. 1) in the form of a tubular section with a longer inner ring cavity 3 of a larger diameter limited than the inner diameter of the test pipe string 1. Seal 4 (Figs. 1, 4) the sealing unit is located between the lower stationary 5 and the upper movable 6, spring-loaded to each other by means of a spring 7, provided with an external chamfer 8, parts of the housing of the crimping valve.

The seal 4 is multi-tiered due to the separating washer 9 (Fig. 2) with external chamfers 10. In the lower stationary part 5 of the case of the crimping valve, the upper and lower anchor nodes are sequentially arranged, each of which is made in the form of a pair of two shoulders mounted on its common hinge 11 , 12 (Fig. 4) of the drive levers 13, 14, respectively. Each anchor node is equipped with an individual drive, consisting of wedges 15, 16 (figure 2) with the corresponding springs 17, 18 (figure 1).

The drive levers 13, 14 are installed so that they have the ability to interact with each other, i.e. be engaged (figure 1), which deprives the upper anchor node of the opportunity to unfold, and also be disconnected from each other, in which the anchor nodes can anchor their anchor ends at the junction 19 (figure 3) of the pipe string 1 and shoe 2 ( figure 1, 2), respectively. The pressure testing valve is equipped with a head 20 (FIGS. 2, 4, 5) for a catcher lowered on a rope of a special winch (not shown). To impart gravity, the crimping valve is equipped with a load of 21 (figure 1). After assembling the pressure test valve, its drive arms 13, 14 (Figs. 4, 5) are fixed by means of cotter pins 22, 23. The lower end of the test pipe string 1 (Figs. 1, 2, 3) ends with a sleeve 24, which is a fragment of this column with an internal with a diameter not exceeding the same size of the pipe string itself 1.

The operation of the device is as follows. When the crimping valve is lowered into the pipe string 1, the cotter pins 22, 23 (FIGS. 4, 5) are removed alternately.

The catcher at the end of the rope of a special winch is passed through a lubricator (not shown) and connected to the head 20. The lubricator is installed at the entrance to the column of the tested pipes 1. The drive levers 13 (Fig. 1) of the upper anchor assembly are reduced to the center due to their interaction with drive levers 14 of the lower anchor node. Due to the wedge 16 with the spring 18, the drive levers 14 are pressed against the walls of the pipe string 1, and the upper movable part 6 of the pressure valve body is moved apart from the lower part 5 of the pressure valve body by the wedge 15, which is supported from below by the upper arms of the drive levers 13. The sealing elements 4 are in free condition - not distributed.

When the pressure test valve enters shoe 2 (FIGS. 1, 2), the drive levers 14 diverge, releasing the analog levers 13, the wedge 15, due to the spring 17, moves down from the upper movable part 6 of the pressure test valve body, which, under the action of the spring 7, in turn, shift downward relative to the lower part 5 of the crimping valve body, expanding the sealing elements 4, i.e. providing a landing in the sealing assembly. A liquid pressure is created above the crimping valve and the pipe string 1 is compressed. In the crimping process (Fig. 2), the axial forces arising from the load 21, from the test pressure of the liquid, are absorbed by the shoe 2 through the drive levers 14, the hinge 12, mounted in the lower stationary part 5 of the crimping valve body.

If the crimping was successful and the pipe string was tight, then the crimping valve is lifted up using a special winch. If a leak is detected, it is necessary to determine at what level the pipe string 1 is located. To do this, you have to test the pipe string 1 at intervals, for example, according to this scheme:

- dividing the pipe string in half, which will speed up the detection of leaks.

When lifting the crimping valve to the required level under the action of the load 21 (Fig. 1), overcoming the force of the spring 7, the stationary 5 and the movable 6 parts of the body of the crimping valve diverge, releasing the sealing elements 4. Upon reaching the calculated level, the crimping valve lowers down to the contact of the actuating levers 13 (FIG. 3) with the closest joint 19 of the pipe string. Guided by the weight indicator on a special winch, the crimping valve comes off from junction 19 and again sits on junction 19, thereby freeing it from possible debris, which increases the reliability of landing. In this case, the axial forces are absorbed by the drive levers 13 through the hinge 11. The rest of the pressure test is similar to the previous one.

In case of leak detection, the upper half of the pipe string 1 is subjected to further pressure testing, and in the absence of leakage, the lower, suspected half of the pipe string 1. For this, the pressure test valve is removed at the wellhead and recharged (Fig. 1) for re-launching for testing the tightness of a more specific pipe string interval, etc. - to accurately determine the level of leakage.

The principle of operation of the crimping valve is such that the selection of the crimping interval is carried out during its movement and from the bottom up. the upper anchor unit does not pass through the junction of the pipe string 1 when the pressure test valve is lowered down, but is activated by the crimping mode mechanically due to the kinematic relationship of the nodes included in the device.

If you use an automatically catching and uncatching catcher, sealed at the end of the winch cable, i.e. mechanically or electrically controlled automatic catcher, then there is no need for a lubricator. After installing the crimping valve at the required level, the catcher is detached from the head 20 and removed from the pipe string 1, which is subsequently plugged and tested for leaks.

The device has a simple design, increased reliability in operation and allows interval testing of the pipe string in the well.

Claims (1)

A device for periodically crimping a pipe string in a well, comprising a pressure test valve that is launched into the pipe string, including a housing connected to the head for the catcher, an anchor assembly with a set of actuating latches in the form of levers, a sealing assembly with a seal installed with the possibility of fitting it, characterized the fact that it contains mounted on the lower end of the test interval of the pipe string shoe in the form of a tubular section with a limited length of the inner annular cavity more times a measure than the inner diameter of the test pipe string, the seal of the sealing assembly is located between the lower fixed and upper movable spring-loaded to each other and provided with an external chamfer parts of the pressure testing valve body, the anchoring assembly is made of upper and lower anchoring valves located in series in the lower stationary part of the pressure testing valve body nodes, each of which is equipped with an individual drive in the form of a wedge with a spring and made in the form of a pair of two shoulders mounted on hinge with the possibility of interaction between the drive levers with the lower anchor ends at the junction of the pipe string and shoe, respectively.

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