RU2268993C1 - Device for hydraulic pipe string testing - Google Patents

Abstract

FIELD: mining industry, particularly devices to provide periodic air testing of pipe string inside well.

SUBSTANCE: device comprises pressurizing valve having body with longitudinal groove and provided with head for fishing tool receiving. The valve includes anchoring unit having rod, driving mechanism and lever-like fixer set, sealing assembly with sealing means installed on the body and adapted for sealing means receiving. The device also has sleeve for pressurizing valve installation arranged at lower end of pipe string section to be air-tested, shoe made as a tube with inner annular cavity having diameter greater than inner diameter of pipe string to be air-tested. The device comprises sealing unit including lower and upper movable pistons and sealing member arranged between the pistons. Upper movable piston is provided with relief valve from the first piston side and with driving mechanism with spring-loaded piston from the second side. The relief valve has head corresponding to fishing tool. Lower piston is connected with the body provided with fixer set for anchoring unit receiving arranged in the body groove. The anchoring unit is made as a pair of double-armed pinned levers having lower ends which may cooperate with the shoe and spring-loaded wedge. The levers also have upper ends cooperating with spring-loaded rod through flat kinematic pair made as chain link.

EFFECT: simplified structure and increased 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 retainer pipe and sits on its conical chamfer, and then a latch and a seal are introduced into the axial channel of the retainer pipe 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 stoppipe, 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 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 one-arm levers and a drive mechanism with a pusher connected to the core by a calibrated shear coping and installed in the axial channel of the housing with the possibility of axial movement. 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 the generally known material of the elastic element is prone 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.

A device for crimping a pipe string, comprising a pressure test valve that runs into the pipe string in the well, consisting of a body with a longitudinal groove, equipped with a head for the catcher, an anchor assembly, consisting of a rod, a drive mechanism and a set of clamps in the form of levers, a sealing assembly with a sealant, installed on the continuation of the housing with the possibility of a seal being fitted, it is designed so that it contains a sleeve for the crimping valve installed on the lower end of the test interval of the pipe string, under the sleeve of the shoe in the form of a pipe with an inner annular cavity of a larger diameter than the inner diameter of the pipe string being pressed, a sealing assembly consisting of a lower and an upper movable piston and a sealing element located between the latter, the upper movable piston being provided on one side with an unloading valve with a head under catcher, and on the other - a drive mechanism with a spring-loaded rod, while the lower piston is connected to the housing, in the longitudinal groove of which is located a set of clamps the assembly, made in the form of a pair of two shoulders mounted on the axis of the levers with the possibility of interaction with their lower ends with a shoe and a spring-loaded wedge, and the upper ends with a spring-loaded rod through a flat kinematic pair in the form of a chain link.

Figure 1 shows a longitudinal section of the crimping valve on the frontal projection; figure 2 is a longitudinal section of a crimping valve on a profile projection; figure 3 is a longitudinal section of the lower end of the test interval of the pipe string with a sleeve and a shoe; figure 4 is a longitudinal section of the device at the level before the entrance of the latches in the shoe; figure 5 is a longitudinal section of the device in a fixed position in the pipe string.

The device consists of a pressure testing valve (Fig. 1, 2), launched into the string, for example, tubing 1 (Fig. 3), located in the well (not shown) and equipped with a sleeve installed on the lower end of the crimped interval of the tubing 2 with a shoe 3, in which an annular cavity (bore) 4 of a larger diameter than the inner diameter of the tubing string is made, holes 5 are provided to reduce the accumulation of debris, the formation of deposits in the annular cavity 4.

The inner surface of the sleeve 2 should correspond to a similar surface of the cylinder of the sucker rod pump, i.e. must have the necessary characteristics of hardness, resistance to corrosion and surface cleanliness so that there is no deposition of paraffin. On the other hand, the sleeve can be made in a reinforced version: the inner surface of the steel casing is filled, for example, with polyamide, which also meets the requirements for the sleeve.

The pressure testing valve (FIGS. 1, 2) consists of a housing 6 with a longitudinal groove 7, a sealing assembly containing the lower 8, upper movable 9 pistons and a rubber seal 10 located between the last ones. The upper movable piston 9 is equipped on one side with a relief valve made in in the form of a ball 11, preloaded by a spring 12 to a saddle 13 through a ball holder 14 with a head 15 for a catcher (not shown) mounted on the end of a rope of a special winch (not shown). The saddle 13 is installed in the upper movable piston 9 through the saddle holder 16 through the washer 17.

On the other hand, the upper movable piston 9 is connected to the rod 18, mounted in the lower piston 8 on the spring 19. The lower piston 8 is connected to the housing 6, in the longitudinal groove 7 of which there is a set of latches of the anchor assembly, made in the form of a pair of two shoulders mounted on the axis 20 levers 21 with the possibility of interacting with their lower ends with a shoe 3 (Figs. 4, 5) and a spring-loaded wedge 22, actuated by a spring 23, and with the upper ends with a spring-loaded rod 18 through a flat kinematic pair in the form of chain links with jaws 24 mounted on a common axis 25 in the rod 18 and on the respective axes 26, 27 located at the upper end of the arms 21.

For fluid passage when opening the discharge valve, radial holes 28 are provided in the movable upper piston 9 (Fig. 1), and in the saddle 13, saddle holder 16 and stem 18, respectively, central holes 29.

The pressure testing valve is stored in the assembled (combined) form of levers 21, the position of which is fixed with a cotter pin 30 (Fig. 2) located in the corresponding holes of the housing 6 and levers 21. In the storage position, the lower 8 and upper movable 9 pistons are apart, and the sealing element 10 is, respectively, in the initial undeformed state. Before the descent into the tubing string, the load 31 is attached to the lower end of the crimping valve using an adapter 32, which helps to overcome the friction forces that occur during the descent.

The operation of the device for crimping the pipe string is that, for example, a tubing string is lowered into the injection well, the bottom of which is equipped with a sleeve 2 and a shoe 3 (Fig. 3). The pressure testing valve with a load of 31 (Fig. 1) is sent to the tubing string 1 and lowered to the level where the pin 30 is installed (Fig. 2). Remove the pin 30, after which the lower ends of the two shoulders of the levers 21 tend to open in different directions under the action of a spring-loaded wedge 22 on the lower side and the same spring rod 18 on the upper side through a flat kinematic pair in the form of a chain link with cheeks 24 mounted on the corresponding axes 25 , 26, 27. Thus, the lower ends of the two-arm levers 22 are pressed against the inner wall of the tubing string along the entire downward movement of the crimping valve. The crimping valve in the initial position, with the pistons 8, 9 apart, with the initial clearance between them (see Fig. 4), the sealing element 10 in the initial state falls into the sleeve 2. With a further movement of the crimping valve downward, the lower ends of the levers 21 fall into the annular cavity 4, diverge and abut against the annular protrusion of the shoe 3. At the same time, the rod 18, connected with the upper movable piston 9, moves downward relative to the lower piston 8, reducing the previously existing gap between them, preliminary landing disappears a sealing element 10, which ensures tightness between the sleeve 2 and the pistons 8, 9. And in the process of crimping the tubing string, the final fit of the sealing element 10 is obtained and the gap between the pistons 8, 9 completely disappears due to the fluid pressure on the upper movable piston 9.

After crimping the tubing string, a catcher (not shown) descends to the last with the help of a special winch. The catcher engages with the head 15 of the crimping valve. Due to the tightness of the winch rope, the unloading valve 11. The liquid located above the pressure valve flows into the annulus, after which the pressure is equalized and the pressure valve breaks from the sleeve 2 and shoe 3. In this case, the lower ends of the levers 21 are forced upward from the annular cavity 4 compress, pushing up the movable upper piston 9 from the lower piston 8, thereby wedging the sealing assembly. Favorable conditions are created for straining the pressure test valve from its place.

The pressure testing valve is removed from the tubing string, washed, lubricated, levers are reduced and cotter-pin (figure 2).

If the tubing string has withstood pressure testing, then it is left for further operation and after the expiration of the billing period it is again subjected to the next pressure testing, etc. If a leak is detected in the tubing string, it must be replaced.

A device for crimping a pipe string provides periodic crimping, while practically maintaining its useful flow area.

Claims (1)

A device for crimping a pipe string, comprising a crimping valve for starting into the pipe string in the well, consisting of a body with a longitudinal groove, equipped with a head for the catcher, an anchor assembly, consisting of a rod, a drive mechanism and a set of clamps in the form of levers, a sealing assembly with a sealant, mounted on the housing with the ability to fit the seal, while it contains a sleeve under the crimping valve, mounted on the lower end of the test interval pipe string, located under the sleeve shoe in de pipes with an inner annular cavity of a larger diameter than the inner diameter of the pipe string being tested, a sealing assembly consisting of a lower and an upper movable piston and a sealing element located between the latter, the upper movable piston being equipped on one side with an unloading valve with a head for a catcher, and on the other - a drive mechanism with a spring-loaded stem, while the lower piston is connected to the housing, in the longitudinal groove of which is located a set of latches of the anchor assembly, made in as a pair of two-shouldered levers mounted on the axis with the possibility of interaction with their lower ends with a shoe and a spring-loaded wedge, and the upper ends with a spring-loaded rod through a flat kinematic pair in the form of a chain link.

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