Method for performing repair work on a branch from a main gas pipeline to a gas distribution station, and / or at a gas distribution station, and / or on the outlet gas pipelines of a gas distribution station without interrupting the gas supply to the consumer

Abstract

FIELD: gas industry.SUBSTANCE: transportation of natural gas through main gas pipelines, to methods for supplying natural gas to consumers, used in carrying out emergency, preventive and repair work at gas distribution stations. In the proposed method, the branch from the main gas pipeline to the gas distribution station, and / or the gas distribution station, and / or the outlet gas pipelines of the gas distribution station are taken out for repair. In this case, compressed natural gas is supplied to the consumer using a mobile automobile gas filling station. Natural gas is supplied to the consumer from mobile gas supply modules, the number of connection points of which L is determined by the algorithm L=Q / 250 rounded up, and the total required number of mobile modules N is determined by the algorithm N=(Q / V)* T* (P / 6) rounded up, where Q is the consumer's gas consumption per hour, V is the useful volume of one mobile gas supply module, T is the time of repair work, P is the pressure of natural gas that must be maintained in the gas pipeline to the consumer. The pressure of natural gas supplied to the consumer is monitored using a pressure gauge installed on the outlet gas pipeline from the gas distribution station. Refuelling of mobile gas supply modules at the work site is carried out from a mobile automobile gas tanker.EFFECT: efficient gas supply.2 cl, 1 dwg

Description

[0001] The invention relates to the gas industry, specifically to the transportation of natural gas (NG) through main gas pipelines (MGP), to methods for providing NG to the consumer, and can be used in carrying out emergency, preventive and repair work at gas distribution stations (GDS).

[0002] Currently, when carrying out emergency, repair, and preventive work, the gas distribution station is usually shut down, with mandatory notification to the consumer about the cessation of gas supply.

[0003] A known method for repairing a gas distribution station involves ensuring uninterrupted gas supply to the consumer from an adjacent gas distribution station. This scheme is only applicable in the case of a closed gas distribution system and only if there is natural gas in the supply pipeline.

[0004] A known method for repairing gas distribution stations (GDS) involves bypassing the GDS via a bypass line connecting the inlet and outlet gas pipelines to prevent interruption of gas supply to consumers, ensuring short-term gas supply to the consumer (clause 9.2.2 of STO Gazprom 2-3.5-051-2006). This scheme has several drawbacks: diverting gas through the bypass is only permitted for a short period of time, gas may be of inadequate quality delivered to the consumer, and only if there is natural gas in the supply pipeline.

[0005] To ensure uninterrupted gas supply to consumers during repair work, it is possible to use temporary pressure reduction units or “mobile Mini GDS” (clause 9.1.11 of STO Gazprom 2-3.5-051-2006), the disadvantage of this technical solution is the need for a site of sufficient size for its placement, limitations on productivity (no more than 10 thousand m 3 / h), as well as the presence of natural gas in the supply gas pipeline.

[0006] A known method for supplying gas to consumers during repair, reconstruction, or technical re-equipment of existing gas distribution stations (GDS) is using a mobile gas supply unit (MGSU) (RU Patent 2716659 "Mobile Gas Supply Unit"). The MGSU, like the GDS, includes units for switching, cleaning, heating, and reducing gas. To connect the MGSU to the main gas pipeline or to a mobile gas refueling truck (MGT), the MGSU includes shut-off valves at the inlet of the main and bypass gas supply lines to the consumer, as well as a valve for supplying gas from a branch of the main gas pipeline and a shut-off valve at the inlet of the line between the supply valve and the shut-off valve of the main line. The disadvantage of this technical solution is the need for natural gas in the supply gas pipeline to the gas distribution station to connect the mobile gas distribution station, as well as the need for several mobile gas distribution stations when supplying gas to the consumer from a mobile gas filling station.

[0007] A known method is indicated in the description of the invention to the patent of the Russian Federation No. 2642905 Russian Federation, IPC 17 D 1 / 00 ​​“Method for performing repair work on a gas distribution station of a main gas pipeline without interrupting gas supply to the consumer” (Mishin O.L., Averkov V.S., Farrakhov S.V. No. 2016152397; declared 12 / 28 / 2016; published 01 / 29 / 2018, Bulletin No. 4). In the specified method for performing repair work at a gas distribution station of a main gas pipeline without interrupting the gas supply to the consumer, natural gas is taken from the main gas pipeline at the inlet of a technically sound gas distribution station, subjected to adiabatic expansion with the performance of external work to generate the cold necessary for the transition of natural gas to the liquid phase, separated from the gas phase, liquefied natural gas is obtained, which is delivered in a cryogenic transport tank to the gas distribution station to be repaired, regasified, and supplied to the consumer.The disadvantages include the complex and lengthy physical process of adiabatic expansion during throttling of natural gas with the performance of external work to generate the cold required for the transition of natural gas to the liquid phase, separating it from the gas phase to obtain liquefied natural gas, which must be transferred to a cryogenic transport tank, transported to the gas distribution station to be repaired, regasified with the use of additional costs and supplied to the consumer, in addition, the need to use several cryogenic tanks; while one is used to supply gas, the other must be refueled at the same time.

[0008] The closest to the declared technical solution is the method described in the article by Batalov I.A., Denisov Ya.V., Sopin V.F. "Improving the quality of gas supplies to consumers during repair work on gas pipeline branches" (Omsk Scientific Bulletin. 2021. No. 3 (177). Pp. 44-48. DOI: 10.25206 / 1813-8225-2021-177-44-48) - a prototype. In this method, in order to ensure the possibility of supplying consumers with gas when a branch from the main gas pipeline with a GDS located at the end of the branch is taken out for repair, the option of using a gas distribution system with a connection to the gas pipeline at the GDS inlet to supply gas to the GDS communications and further to consumers is considered.

[0009] The disadvantages of the prototype include the need to use several PAGZs and organize their shift work, which is labor-intensive and quite financially expensive.

[0010] The technical problem that the claimed invention is aimed at solving is the uninterrupted supply of gas to the consumer during repair work on the branch from the main gas pipeline to the gas distribution station, and / or at the gas distribution station itself, and / or its outlet gas pipelines.

[0011] The technical result is achieved in that in the proposed method for performing repair work on a branch from the main gas pipeline to the gas distribution station, and / or at the gas distribution station, and / or on the outlet gas pipelines of the gas distribution station, without interrupting the gas supply to the consumer, the branch from the main gas pipeline to the gas distribution station, and / or the gas distribution station, and / or the outlet gas pipelines of the gas distribution station are taken out for repair, compressed natural gas is supplied to the consumer using a mobile automobile gas tanker, wherein the supply of natural gas to the consumer is carried out from mobile gas supply modules, the number of connection points of which L is determined by the algorithm L = Q / 250 rounded up, and the total required number of mobile modules N is determined by the algorithm N = (Q / V) * T * (P / 6) rounded up, where Q is the consumer's gas consumption per hour,V is the useful volume of one mobile gas supply module, T is the time of repair work, P is the pressure of natural gas that must be maintained in the gas pipeline to the consumer, while the pressure of natural gas supplied to the consumer is monitored by a pressure gauge installed on the outlet gas pipeline from the gas distribution station, while refueling of mobile gas supply modules at the work site is carried out from a mobile automobile gas tanker.

[0012] We will consider the implementation of the proposed method using an example.

[0013] For example, it is necessary to ensure uninterrupted gas supply to a consumer with an average natural gas consumption of 525 m 3 / hour, pressure of 0.6 MPa for the duration of repair work at the gas distribution station in the amount of 5 hours and the useful volume of one mobile module of 440 m 3 .

[0014] Fig. 1 shows a basic diagram of the implementation of the proposed method. Where: 1 - main gas pipeline; 2 - branch gas pipeline to the GDS; 3 - GDS; 4 - gas pipeline to the consumer; 5 - mobile gas supply modules; 6 - mobile automobile gas filling station; 7 - pressure gauge; 8 - gas consumer; 9 - shut-off valves; 10 - spark plug valves; 11 - mobile module connection valves.

[0015] Determine the connection location of the mobile gas supply modules depending on the location of the repair work, the disconnected section, the technical feasibility of connection, transport accessibility for loading and unloading operations for the installation of mobile gas supply modules and the accessibility of the mobile gas supply module.

[0016] Based on the consumer's natural gas consumption, the number of mobile gas supply module connection points, L, is determined using the algorithm L = Q / 250, rounded up. The total required number of mobile modules, N, is calculated using the algorithm N = (Q / V) * T * (P / 6), rounded up, where Q is the consumer's hourly gas consumption, V is the useful volume of one mobile gas supply module, T is the repair time, and P is the natural gas pressure that must be maintained in the gas pipeline to the consumer. 4

[0017] L=Q / 250=525 / 250=2.1~3 connection points;

[0018] N=(Q / V)*T*(P / 6)=525 / 440*5*(6 / 6)=5.96~6 mobile modules.

[0019] Thus, 6 mobile modules with a useful volume of one mobile module of 440 m 3 , connected at 3 points, will ensure uninterrupted gas supply to the consumer with an average natural gas consumption of 525 m 3 / hour, at a pressure of 0.6 MPa for the duration of repair work at the gas distribution station for 5 hours.

[0020] Carry out delivery, unloading and connection of mobile gas supply modules 5 at the work site in accordance with the calculations made.

[0021] Connect mobile gas supply modules 5 to each other, to the gas supply control unit 6, and to the gas pipeline to consumer 4 for gas supply. Check the tightness of the threaded and detachable connections by soaping them after opening the filling valves on mobile gas supply modules 5 and the gas supply control unit 6. Next, smoothly transfer the gas supply to consumer 8 to backup gas sources in the form of mobile gas supply modules 5 by opening the valves in the natural gas consumer's pipelines and closing the shut-off valves 9 downstream of the repair site along the gas flow path. Ensuring double isolation of the repair site, ensuring its tightness, and purging the repaired section with inert gas is a mandatory condition for performing these works. Repairs are performed on-site.Upon completion of repair work, the pipelines being repaired are purged with natural gas to displace oxygen to the required levels. A smooth transition to the consumer's gas supply is performed according to the standard procedure, while simultaneously shutting off the natural gas supply from the backup natural gas sources. The filling valves on the mobile gas supply modules and the gas control unit are closed, and gas is released from the filling hoses onto the plugs of the mobile gas supply modules.

[0022] This achieves the following effect:

[0023] ensuring uninterrupted gas supply to consumers for a long period during repair work on the gas distribution station and the linear part of the main gas pipeline by refueling mobile gas supply modules with a mobile automobile gas filling truck directly at the point of their connection in the gas consumer networks, without additional transportation of the modules to the CNG filling stations;

[0024] Possibility of carrying out work on the output gas pipelines of the gas distribution station, ensuring double isolation of the section of the gas pipeline being repaired, without interrupting the gas supply to consumers.

Claims

1. A method for performing repair work on a branch from a main gas pipeline to a gas distribution station, and / or at a gas distribution station, and / or on the outlet gas pipelines of a gas distribution station, without interrupting the gas supply to the consumer, in which the branch from the main gas pipeline to a gas distribution station, and / or the gas distribution station, and / or the outlet gas pipelines of a gas distribution station are taken out for repair, compressed natural gas is supplied to the consumer using a mobile automobile gas refueling truck, characterized in that the supply of natural gas to the consumer is carried out from mobile gas supply modules, the number of connection points of which L is determined by the algorithm L=Q / 250 rounded up, and the total required number of mobile modules N is determined by the algorithm N=(Q / V)*T*(P / 6) rounded up, where Q - gas consumption by the consumer per hour, V is the useful volume of one mobile gas supply module, T - time of repair work, P is the pressure of natural gas that must be maintained in the gas pipeline to the consumer, In this case, the pressure of natural gas supplied to the consumer is monitored using a pressure gauge installed on the outlet gas pipeline from the gas distribution station.

2. The method according to paragraph 1, characterized in that the refueling of mobile gas supply modules at the work site is carried out from a mobile automobile gas tanker.

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