RU2805111C1 - Method for performing repair work at the facilities of the gas transmission system without interrupting the gas supply to the consumer - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: methods for providing gas to the consumer used in the performance of emergency and repair work on the linear part of the main gas pipelines and gas distribution stations. A method for performing repair work at the facilities of the gas transmission system without interrupting the gas supply to the consumer, in which the gas distribution station to be repaired is turned off, taken out for repair, gas is supplied through a pressurized tie-in to a low-pressure gas pipeline, sections of the gas pipeline-outlet to be repaired are switched off in series or in parallel with the gas distribution station, before the objects are taken out for repair, a mobile gas distribution station is installed and connected through connections for tapping under pressure to the main gas pipeline on the one part and to the low-pressure gas pipeline on the other, gas is transported through the mobile gas distribution station, the objects to be repaired are cut off, repairs are carried out.

EFFECT: simplifying the implementation and expanding the scope of the method for performing repair work at the facilities of the gas transmission system without interrupting the gas supply to the consumer.

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Description

The invention relates to the gas industry, specifically to methods of providing gas to consumers, and can be used when performing emergency and repair work on the linear part of main gas pipelines and gas distribution stations.

There is a known method for repairing a main gas pipeline and a mobile gas pumping unit for its implementation (RF Patent No. 2567413, published 09/10/2014). The essence of the invention is to disconnect the defective section from the main gas pipeline by shutting off the line valves at both ends. A bypass and a bypass unit are connected to the main gas pipeline parallel to the linear valves. Gas is pumped out from the defective area using a liquid jet ejector using a liquid pump until a pressure of at least 1 atm is created in the defective area. Then the gas is released into the environment until pressure is created in the defective area close to atmospheric pressure, and it is ventilated with ambient air through a bypass using an ejector until an explosion-proof gas concentration is formed in the defective area. After the repair, use an ejector to pump out air from the repaired area until a vacuum is formed and fill the repaired area through the bypass with gas from the gas pipeline.

The disadvantages of this method are: limitation of the scope of application, due to the impossibility of using connections simultaneously to the main gas pipeline and a low-pressure gas pipeline, and the complexity of implementing the method.

There is a known method for repairing an emergency section of a gas pipeline (RF Patent No. 2638895, published 12/18/2017). The essence of the invention is to repair an emergency section of an external gas pipeline by assembling a temporary bypass device under stationary conditions, including a sequential connection of an elastic rubber hose with thread reinforcement, at the ends of which flanges with a frame and two complex shut-off and control devices are hermetically fastened. The emergency section is disconnected by connecting a temporary bypass device to the existing gas pipeline and gas is supplied to the consumer. Then, the planned repair work is carried out in the disconnected area, upon completion of which the gas supply is turned off, purged through the discharge candles at the corresponding gas distribution points, and the bypass line is removed. After connecting the repaired section of the gas pipeline to replace the emergency one, the supply of natural gas to consumers is resumed by carrying out hot work and testing the seams for strength and tightness.

The disadvantages of this method are: limitation of the scope due to the impossibility of using connections simultaneously to the main gas pipeline and the low pressure gas pipeline.

There is a known method for performing repair work at a gas distribution station of a main gas pipeline without interrupting the gas supply to the consumer (RF Patent No. 2642905, published on January 29, 2018), which we chose as a prototype. The essence of the invention is to carry out repair work at a gas distribution station without stopping the gas supply to the consumer, in which the gas distribution station is taken out for repairs, natural gas is taken from the main gas pipeline, and at the entrance of a technically sound gas distribution station is subjected to adiabatic expansion with external work performed to generate the cold necessary for the transition natural gas into the liquid phase, it is separated from the gas phase, liquefied natural gas is obtained, which is delivered in a cryogenic transport tank to a gas distribution station to be repaired, regasified, and supplied to the consumer.

The disadvantages of this method are: high labor intensity due to the need to use a gas liquefaction unit and the use of a container for storing and transporting liquefied gas, limited scope due to the impossibility of connecting the main gas pipeline to a low-pressure gas pipeline and, accordingly, repairing the gas pipeline branch.

The technical problem solved by the proposed invention is the creation of a method that is easy to implement and has a wide scope of application for performing repair work at gas transportation system facilities without interrupting the gas supply to the consumer.

The technical result from the use of the invention is to simplify the implementation and expand the scope of application of the method for performing repair work at gas transportation system facilities without interrupting the gas supply to the consumer.

The technical result is achieved by the fact that in the method of performing repair work at gas transportation system facilities without stopping the gas supply to the consumer, the gas distribution station to be repaired is turned off, taken out for repairs, gas is supplied through a pressure tap into the low-pressure gas pipeline, and the gas distribution station to be repaired is turned off in series or in parallel with the gas distribution station. sections of the gas pipeline branch, before the objects are taken out for repair, a mobile gas distribution station is installed and connected through connections for tapping under pressure to the main gas pipeline on the one hand, and to the low pressure gas pipeline on the other, the gas is transported through the mobile gas distribution station, the objects to be repaired are cut off, and the repair.

In FIG. Figure 1 shows a diagram of connecting a mobile gas distribution system (1) to the main gas pipeline (2) and a low-pressure gas pipeline (3) to ensure uninterrupted gas supply to the consumer when repairing a section of the gas pipeline branch (4) and/or gas distribution system (5).

The method is carried out as follows.

In accordance with STO Gazprom 2-2.3-116-2016, an inspection of the aerial intersection (6) of the main gas pipeline (2) with a low-pressure gas pipeline (3) is carried out to assess the possibility of connecting any mobile gas distribution station (1) to the main gas pipeline (2) through a tie-in under pressure into the main gas pipeline (2) on one side and the low pressure gas pipeline (3) on the other side.

Connecting a mobile gas distribution station is possible if the results of non-destructive quality control of pipe metal at the site of the proposed insertion comply with the requirements of STO Gazprom 2-2.3-116-2016.

A mobile gas distribution station (1) is installed and connected to the main gas pipeline (2) on one side and to the low pressure gas pipeline (3) on the other side using a pressure tap in the manner specified in STO Gazprom 2-2.3-116-2016. Install a ball valve (7) of the same diameter as the diameter of the main gas pipeline (2) and a ball valve (8) of the same diameter as the low pressure gas pipeline (3) using welding. Open the valves (7, 8), transport gas through the mobile gas distribution system (1), close the valves (9, 10), if the gas pipeline outlet is being repaired (4) or valves (10, 11), if the gas distribution system is being repaired (5), cut off the gas pipeline - outlet (4) using any metal cutting tool. Lay a new pipe of dimensions corresponding to the one being repaired. The new pipe is connected to the remaining gas pipeline branch (4) by a welded joint. Open the taps (9, 10) or (10, 11), transport the gas through the repaired gas pipeline-outlet (4) to the low-pressure gas pipeline of the distribution networks (3) through the gas distribution station (5). Turn off the taps (7, 8) and turn off the mobile gas distribution system (1); using a metal cutting tool, disconnect the mobile gas distribution system (1).

The invention is illustrated below by the following examples and figure 1.

Example 1.

To repair a gas branch pipeline (4) with a diameter of 150 mm and a length of 14890 m, connecting the main gas pipeline (2) with the gas distribution station (5). To do this, an inspection of the connection point of the mobile gas distribution station “Istok-50” (5) to the main gas pipeline (2) is carried out in terms of the possibility of making a pressure tap into the main gas pipeline (2) on the one hand and the low pressure gas pipeline (3) on the other side for its connections. To do this, non-destructive testing is carried out using an ultrasonic method, the test results correspond to clause 5.6.4 of STO Gazprom 2-2.3-116-2016, which is the fulfillment of the criterion for the possibility of using this method. A mobile gas distribution station (1) is inserted under pressure into the main gas pipeline (2), using the design of the insertion unit in accordance with section 6 of STO Gazprom 2-2.3-116-2016. Using welded joints, install a tap (7) with a diameter of 50 mm. A mobile gas distribution station (1) is inserted under pressure into a low-pressure gas pipeline (3) with a diameter of 80 mm, using the design of the insertion unit in accordance with section 6 of STO Gazprom 2-2.3-116-2016. A tap (8) with a diameter of 80 mm is installed using welded joints. Open the taps (7, 8), gas is transported through the Istok-50 mobile gas distribution station (1), close the taps (9, 10), cut off the gas pipeline outlet (4) using a metal cutting tool, lay a new pipe , connected to the remaining gas pipeline-branch (4) using welded joints, open the taps (9, 10), gas is transported through the repaired gas pipeline-branch (4) to the low-pressure gas pipeline (3) through the gas distribution station (5), close the taps (7, 8), turn off the mobile gas distribution station (1) using a metal cutting tool.

Example 2.

To repair a gas branch pipeline (4) with a diameter of 150 mm, a length of 13360 m, connecting the main gas pipeline (2) with the gas distribution station (5), an inspection of the connection point of the mobile gas distribution station “Istok-50” (5) to the main gas pipeline (2) is carried out in part of the possibility of making a pressure tap into the main gas pipeline (2) on one side and a low pressure gas pipeline (3) on the other side for its connection. To do this, non-destructive testing is carried out using an ultrasonic method; the test results do not comply with clause 5.6.4 of STO Gazprom 2-2.3-116-2016, which does not meet the criterion for the possibility of using this method.

Example 3.

To repair the gas distribution station (5), an inspection is carried out of the connection point of the mobile gas distribution station "Istok-50" (1) to the main gas pipeline (2) in terms of the possibility of making a pressure tap into the main gas pipeline (2) on one side and the low pressure gas pipeline (3 ) on the other side to connect it. To do this, non-destructive testing is carried out using an ultrasonic method, the results correspond to clause 5.6.4 of STO Gazprom 2-2.3-116-2016, which is the fulfillment of the criterion for the possibility of using this method. A mobile gas distribution station (1) is inserted under pressure into the main gas pipeline (2), using the design of the insertion unit in accordance with section 6 of STO Gazprom 2-2.3-116-2016. Using welded joints, install a tap (7) with a diameter of 50 mm. A mobile gas distribution station (1) is inserted under pressure into a low-pressure gas pipeline (3) with a diameter of 80 mm, using the design of the insertion unit in accordance with section 6 of STO Gazprom 2-2.3-116-2016. A tap (8) with a diameter of 80 mm is installed using welded joints. Open the valves (7, 8), gas is transported through the Istok-50 mobile gas distribution station (1), close the valves (10, 11), carry out repairs at the gas distribution station (5), open the valves (10, 11), transportation gas is supplied through the gas distribution station (5) to the low pressure gas pipeline (3), close the valves (7, 8), turn off the mobile gas distribution station (1) using a metal cutting tool.

Thus, the invention we propose allows for an easy-to-implement method of performing repair work at gas transmission system facilities without interrupting the gas supply to the consumer due to the fact that gas is transported directly from the main gas pipeline to the low-pressure gas pipeline through a mobile gas distribution station. The invention also makes it possible to expand the scope of application of the method and carry out sequential or parallel repairs not only of the gas distribution station, but also of sections of the gas pipeline branch due to the fact that the mobile gas distribution station is connected through connections for tapping under pressure to the main gas pipeline on one side, and to the low-pressure gas pipeline pressure on the other.

Claims (1)

A method of performing repair work at gas transportation system facilities without interrupting the gas supply to the consumer, in which the gas distribution station to be repaired is switched off, taken out for repairs, gas is supplied through a pressurized tap into the low-pressure gas pipeline, characterized in that the sections to be repaired are disconnected in series or in parallel with the gas distribution station branch gas pipeline, before the objects are taken out for repair, a mobile gas distribution station is installed and connected through connections for tapping under pressure to the main gas pipeline on the one hand and to the low pressure gas pipeline on the other, the gas is transported through the mobile gas distribution station, the objects to be repaired are cut off, and the repairs are carried out.

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