RU2818961C1 - Method and device for control of tightness of crossings through obstacles - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: group of inventions relates to construction and operation of pipelines, particularly gas pipelines. More specifically, the invention relates to methods of monitoring safe operation, state of integrity and tightness of siphon or case, as well as pipelines located in them. Method of controlling tightness of transitions through obstacles consists in the fact that by change of pressure in annular space with the help of pressure gauge, presence of leakage in pipeline is determined, gas analyser is used to determine the presence or absence of gas contamination of the annular space to determine the source of leakage. Device for control of tightness of transitions through obstacles is a shut-off-control unit connected to annular space of the pipeline through a crosspiece forming three branches. On one branch, there is a pressure gauge installed to determine the pressure change in the annular space, on the other, there is a scattering plug for releasing excess media of the annular space, at the third stage, there is a sealed pocket for installation of a device investigating characteristics of the inter-tube space medium, as well as a pressure gauge for pressure control in this pocket.

EFFECT: improvement of quality and information value during control over safe operation of pipelines crossings through obstacles, as well as expansion of operational functionality of control of transitions.

2 cl, 2 dwg

Description

The invention relates to the field of construction and operation of pipelines, in particular gas pipelines. More specifically, the invention relates to methods for monitoring the safe operation, integrity and tightness of a siphon or case, as well as the gas pipelines located in them.

The patent for PM “Underwater Transition” of the Russian Federation No. RU 39676 U1 is known from the prior art (dated 01/19/2004, authors Akberdin A.M. (RU) and others, patent area State Unitary Enterprise “Institute for Energy Resources Transport Problems” (RU), class IPC F17D 1 /00), which describes the device of an underwater passage made according to the “pipe in pipe” scheme, in which, at the point of maximum deflection along the lower generatrix of the outer pipe, a “pocket” is made, inside of which a rocker arm with a float and a rocker travel limiter (stop) are located on a hinge ), while the rocker arm and the limiter are connected to a power source with a signaling device in the electrical network, which turns on when the rocker arm is raised to contact with the limiter. In this case, the “pocket” is equipped with an L-shaped pipe with a valve for connecting a pump for pumping out the liquid accumulating in the “pocket”.

The disadvantage of this technical solution is the complexity of the device due to the presence of a pocket, a rocker, a sensor connected by an electric wire to a signaling device, low reliability of the device due to the presence of rubbing connections, the need for special insulation of the electric wire when pumping aggressive liquids, the inability to use an underwater passage for transportation of gaseous media.

Also known is the patent for PM “Underwater Transition” of the Russian Federation No. RU 77661 U1 (dated 05/30/2008, authors R. G. Sultanov et al., patent area State Unitary Enterprise “Institute for Energy Resources Transport Problems” (RU), IPC class F17D 1/00 ) which describes the design of an underwater crossing made according to the “pipe in pipe” scheme, the presence of a leak is judged by the change in pressure in the interpipe space using a pressure device installed on the onshore part of the crossing, while a differential pressure gauge is used as a pressure device, the positive chamber of which is connected with the inter-tube space, and the negative one - with a reference tank with a pressure equal to the pressure in the inter-tube space in the absence of leakage. The reference container is made of a sealed part of the interpipe space. This technical solution was chosen as a prototype.

The disadvantage of the technical solution is that with the help of this solution it is not possible to determine what caused the change in pressure in the interpipe space: a gas leak or a leak in the outer pipe - casing.

The purpose of the present invention is to detect a fault in an underwater passage of a gas pipeline, as well as the ability to determine the nature of this fault.

The technical result of the proposed method and device for monitoring the tightness of crossings over barriers is to improve the quality and information content when monitoring the safe operation of gas pipeline crossings through barriers, as well as expanding the operational functionality of monitoring crossings.

The technical result is achieved through a method for monitoring the tightness of transitions through barriers, which consists in the fact that monitoring the tightness of a gas pipeline crossing through an obstacle, made according to the “pipe in pipe” scheme, is carried out by monitoring changes in pressure in the interpipe space using a pressure gauge installed in the corresponding shut-off valve - a control unit on the onshore part of the crossing, after which, using a gas analyzer installed externally in a sealed pocket of the shut-off and control unit associated with the annulus, the gas contamination characteristics of the annulus environment are determined, from which a conclusion is drawn about the nature of the damage to the gas pipeline.

The device for monitoring the tightness of transitions through obstacles, made according to the “pipe in pipe” scheme, is a shut-off and adjustment unit installed on the onshore part of the transition, connected to the interpipe space of the gas pipeline through a cross, forming three branches, on one of which a pressure gauge is installed to determine the change pressure in the annulus, on the other there is a dispersion plug for bleeding off excess media of the annulus, on the third there is a sealed pocket for installing a device that studies the characteristics of the annulus environment, as well as a pressure gauge for monitoring the pressure in this pocket.

The essence of the invention is explained below. By changing the pressure in the annulus, a pressure gauge is used to determine the presence of a leak in the gas pipeline, and using a gas analyzer, the presence or absence of gas contamination in the annulus environment is determined, and based on this fact, the source of the leak is determined accordingly: either in the presence of gas contamination in the annulus - a gas pipeline leak, or in the absence gas contamination, respectively, the fact of leakage of the external protective part of the gas pipeline - the casing.

For these purposes, a shut-off and control unit is installed on the onshore part of the transition, connected to the annulus of the gas pipeline through a cross that forms three branches, on one of which a pressure gauge is installed to determine the change in pressure in the annulus, on the other - a dispersion plug to bleed off excess media from the annulus , for example, bleeding gas in case of leakage, the third is formed by a sealed pocket for installing a device that studies the characteristics of the annulus environment, for example, a gas analyzer. The sealed pocket is formed by a pipe with a flange, limited on one side by shut-off and control valves, and on the other side by a plug with a nipple. A pressure gauge is also installed on this branch to monitor the pressure in the sealed pocket.

In fig. Figure 1 shows a diagram of the passage of a gas pipeline through an obstacle - a body of water (sink). The diagram shows:

1 - Obstacle (water body);

2 - Case;

3 - Internal gas pipeline;

4 - Interpipe space;

5 - Head (input / output).

In order to eliminate mechanical damage, dynamic effects, as well as protect them from corrosion, leading to a reduction in service life and the prevention of man-made accidents, gas pipelines are laid through barriers 1 in protective structures - siphons, in such a way that the space between the outer protective part - casing 2 and gas pipeline 3 located inside is closed and sealed.

When crossing water obstacles, the inlet and outlet heads 5 of the siphon are placed on the coastline above the maximum level of the water obstacle. The tightness of the interpipe space between the case 2 and the gas pipeline 3 can be achieved, for example, with various kinds of cuffs.

In fig. Figure 2 shows a diagram of a device for monitoring the tightness of transitions through barriers. The diagram shows:

6 - Pipe with flange;

7 - Cross;

8 - Shut-off and control valves (SVR);

9 - Pressure gauge;

10 - Shut-off and control valves;

11 - Check valve;

12 - Dispersion candle;

13 - Shut-off and control valves;

14 - Counter pipe with flange;

15 - O-ring with grille;

16 - Plug with nipple;

17 - Tee;

18 - Shut-off and control valves;

19 - Pressure gauge;

20 - Shut-off and control valves;

The device for monitoring the tightness of passages through obstacles is a shut-off and adjustment unit installed on the onshore part of the passage in this way: on the external generatrices of the inlet and outlet heads (5) of the siphon, a pipe with a flange (6) is installed by welding, threaded or in another way, so that the cavity of the interpipe space (4) communicated with the cavity of the pipe with a flange (6). A crosspiece (7) is installed at the end of the branch pipe with a flange (6), forming three branches.

A pressure gauge (9) is installed on one of the branches of the cross (7) through the anti-corrosion protection system (8), designed to determine the change in pressure in the interpipe space (4). The flow of the measured medium from the annulus (4) to the pressure gauge (9) is regulated by the ZRA (8).

On another branch of the crosspiece (7), through the anti-tank protection system (10) and the check valve (11), a dispersion plug (12) is installed, which is designed to bleed off excess media formed in the annulus (4) during technological operations and in emergency situations. The dispersion plug (12) is connected through a check valve (11) with a ballast (10).

A sealed pocket is formed on the third branch of the cross (7) for installing a device that studies the characteristics of the annulus environment (4), for example, a gas analyzer. The sealed pocket is formed by a return pipe with a flange (14), limited on one side by an airlock (13), and on the other side by a plug with a nipple (16). The gas analyzer is installed in the return pipe with a flange (14) to measure the gas content of the medium that creates pressure in the interpipe space (4).

The seal between the control valve (13) and the branch pipe with the flange (14) is carried out by an o-ring with a grille (15). The sealing ring with the grille (15) also serves to prevent the gas analyzer or other device installed in the mating pipe with a flange (14) from falling into the annulus (4). The plug with nipple (16) is used to close and seal the return pipe with flange (14) when conducting studies of the environment that creates pressure in the annulus (4).

Next, a tee (17) is installed on the plug with nipple (16), which is designed to carry out auxiliary operations when measuring the parameters of media that create pressure in the annulus (4).

On one of the branches of the tee (17) a shut-off and control valve (18) is installed, designed to control the flow of the measured medium from the annulus (4) to the pressure gauge (19). The pressure gauge (19) is designed to monitor pressure parameters in a sealed pocket formed by a pipe with a flange (14).

On the other branch of the tee (17), a shut-off and control valve (20) is installed, designed to regulate the process of bleeding the test medium from a sealed pocket formed by a branch pipe with a flange (14).

It is worth noting that in the process of using a technical solution, temperatures are also taken into account and controlled: the environment, the water body and the environment of the annulus space, and based on the totality of the data obtained, approxioms and isochores are built, from the graphs of which they judge by indirect signs the integrity of the case located there are gas pipelines in it, and in general about the siphon.

In addition, this invention can be used not only for monitoring the tightness of transitions through barriers, but also for other technological operations related to the operation, maintenance and inspection of gas pipeline transitions, siphons, cases, etc.

An example of the implementation of a technical solution. During a routine inspection of underwater river crossing units, a method and device for monitoring the tightness of crossings over obstacles is used in this way.

After opening the air control valve (8) by the maintenance personnel, an excess of pressure above atmospheric pressure was detected on the pressure gauge (9), and the pressure value is close to the hydrostatic pressure of the liquid column in the river being inspected, taking into account the maximum depth of crossing the water barrier by the siphon.

Then the plug with nipple (16) was removed, the gas analyzer was placed in the return pipe with a flange (14). Installation and actions to seal the plug with nipple (16) relative to the mating pipe with flange (14) have been completed. After that, the BPA (13) is opened to allow the medium to flow from the interpipe space (4), which causes an increase in pressure on the pressure gauge (9). Wait for pressure equalization on pressure gauges (9) and (19). Then the air control valve (13) is closed in order to cut off the return pipe with flange (14) from the interpipe space (4) and seal its cavity. The BRA (20) is opened in order to bleed the parameters of the measured medium, while the bleed process is controlled by a pressure gauge (19). Bleeding is carried out to atmospheric pressure. Next, the plug with nipple (16) is dismantled, the gas analyzer is removed from the mating pipe with flange (14), and the gas analyzer readings are visually monitored.

Case 1: if the pressure gauge (9) shows a pressure higher than or close to the hydrostatic column of liquid, the maximum level of the siphon and the gas analyzer readings do not indicate gas contamination of the environment, we can confidently conclude that the tightness of the siphon case (2) has been compromised.

Case 2: if the pressure gauge (9) shows a pressure higher than or close to the hydrostatic column of liquid, the level of the maximum location of the siphon or close to the operating pressure of the gas pipeline placed in the case and the readings of the gas analyzer indicate gas contamination of the environment, we can confidently conclude that the tightness of the gas pipeline has been compromised .

Claims (2)

1. A method for monitoring the tightness of transitions through obstacles, which consists in monitoring the tightness of a gas pipeline crossing through an obstacle, made according to the “pipe in pipe” scheme, by monitoring changes in pressure in the interpipe space using a pressure gauge installed in the corresponding shut-off and control unit on the coastal part of the crossing, after which, using a gas analyzer installed externally in a sealed pocket of the shut-off and control unit connected to the annulus, the gas contamination characteristics of the annulus environment are determined, from which a conclusion is drawn about the nature of the damage to the gas pipeline. 2. The device for monitoring the tightness of transitions through barriers, made according to the “pipe in pipe” scheme, is a shut-off and control unit installed on the onshore part of the transition, connected to the interpipe space of the gas pipeline through a cross, forming three branches, on one of which a pressure gauge is installed for determining changes in pressure in the annulus, on the other there is a dispersion plug for bleeding off excess media of the annulus, on the third there is a sealed pocket for installing a device that studies the characteristics of the annulus environment, as well as a pressure gauge for monitoring the pressure in this pocket.

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