A system suitable for injecting ethylene glycol into wellhead pipelines

Abstract

The utility model provides an ethylene glycol injection system suitable for a wellhead pipeline, which relates to the technical field of oil and gas exploitation, and comprises a storage tank and a PLC control system. The storage tank is connected to an output pipeline, and the output pipeline is connected to at least one injection pipeline. A first ball valve, a flow meter, an injection pump, an overflow valve, a pressure transmitter, and an outlet ball valve are arranged on the injection pipeline. The flow meter and the injection pump are respectively connected to the PLC control system. Ethylene glycol enters the injection pipeline through the output pipeline to form an injection circulation pipeline. The injection pump outputs at ultra-high pressure, and the ethylene glycol discharged after the pressure is relieved by the overflow valve re-enters the first ball valve, the flow meter, and the injection pump through the outlet ball valve to complete the injection cycle, and is transported to the next pipeline through the high-pressure ball valve, so that the ethylene glycol injection amount can be controlled, and the injection process is continuous and stable.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas exploitation, in particular to a system suitable for injecting ethylene glycol into a wellhead pipeline. Background Art

[0002] With the development of urbanization in my country, more and more places are beginning to use natural gas as fuel. In the process of gas extraction from natural gas fields, the components of natural gas extracted are different due to the diversity of underground conditions. High-pressure natural gas often contains saturated water or free water or various heavy components after extraction. In the process of throttling and transportation at the inlet and outlet, water and hydrate precipitation often occur due to throttling of low-temperature well flow. These solids and liquids cause the entire pipeline to be blocked. One of the process methods is to inject ethylene glycol into the wellhead gas to reduce the formation temperature of hydrates and the dew point temperature of the gas. In the prior art, there are also chemical agents such as methanol, ethylene glycol, etc. injected into the wellhead to inhibit the formation of hydrates, and the injection amount and filling process are completely uncontrollable.

[0003] For example, in the Chinese patent literature, the publication number is CN111456684A, the publication date is July 28, 2020, and the name is a chemical injection system and method for a deepwater underwater wellhead. The chemical injection system for a deepwater underwater wellhead uses a high-pressure pump group to cooperate with multiple low-pressure pump groups. The high-pressure pump group can be used as a high-pressure displacement pump to complete the gas column displacement and agent injection of multiple underwater wellheads in the gas field, reducing the cost investment while also reducing the difficulty of on-site operations. However, the existing technology with the publication number CN111456684A still has shortcomings, and the injection amount and filling process of the chemical agent cannot be controlled. Utility Model Content

[0004] In order to solve the above-mentioned deficiencies of the prior art, the utility model provides a system suitable for injecting ethylene glycol into a wellhead pipeline, which can realize controllable injection volume and continuous and stable injection process.

[0005] The utility model is realized by the following technical solutions:

[0006] A system for injecting ethylene glycol into a wellhead pipeline comprises a storage tank and a PLC control system, and is characterized in that: the storage tank is connected to an output pipeline, the output pipeline is connected to at least one injection pipeline, and a first ball valve, a flow meter, an injection pump, an overflow valve, a pressure transmitter, and an outlet ball valve are arranged on the injection pipeline; the flow meter and the injection pump are respectively connected to the PLC control system, and ethylene glycol enters the injection pipeline through the output pipeline to form an injection circulation pipeline; if the injection pump outputs at ultra-high pressure, the ethylene glycol discharged after the pressure is relieved by the overflow valve re-enters the first ball valve, the flow meter, and the injection pump through the outlet ball valve to complete the injection cycle, and is transported to the next pipeline through the high-pressure ball valve.

[0007] Furthermore, a pulse damper and a sampling valve are provided on one end of the injection pipeline close to the pressure transmitter; the pulse damper eliminates the pressure pulsation caused by the continuous operation of the injection pump, and the sampling valve is used to take out the ethylene glycol sample in the injection pipeline.

[0008] Furthermore, the output pipeline is connected to two independent injection pipelines, one of which is in normal use and the other is inactive. When one of the injection pipelines in use needs maintenance, the other injection pipeline is activated, or when the pipeline gas volume exceeds the design range, the two injection pipelines are opened at the same time to meet the working condition requirements.

[0009] Furthermore, a check valve and a high-sealing stop valve are sequentially arranged at one end of the high-pressure ball valve. The check valve is used to prevent the high-pressure gas from flowing back.

[0010] Furthermore, the output pipeline is provided with a second ball valve and a filter in sequence, and the ethylene glycol flows through the second ball valve and the filter in sequence and then enters the injection pipeline. The second ball valve plays the role of opening and closing the injection pipeline. When the injection pipeline needs to be used, the second ball valve is opened, and when it is not needed, the second ball valve can be closed. The filter is used to filter some impurities in the ethylene glycol to prevent the subsequent mixing of the ethylene glycol and the high-pressure gas from being affected.

[0011] Furthermore, a liquid level monitoring pipeline is provided on one side of the storage tank, and the two ends of the liquid level monitoring pipeline are respectively connected to the upper and lower ends of the storage tank, and a fourth ball valve is provided at the connection point, and a liquid level remote transmitter is provided in the middle of the liquid level monitoring pipeline. The liquid level in the storage tank can be monitored in real time through the liquid level remote transmitter, and a warning message is sent to prompt the addition of ethylene glycol if the liquid level is too low.

[0012] Furthermore, the storage tank is connected to an input pipeline, the inlet end of the input pipeline is connected to an electric pump, and a third ball valve is arranged on the input pipeline, and ethylene glycol is injected into the storage tank to a set height of the storage tank through the electric pump.

[0013] Furthermore, a pressure gauge and a valve group are provided above the storage tank for monitoring the pressure in the storage tank, and a breathing valve is used to isolate the air from direct contact with the liquid in the storage tank.

[0014] Furthermore, a sewage pipeline is provided below the storage tank and is connected to a sewage pool. A sewage valve is provided on the sewage pipeline to discharge some impurities in the storage tank.

[0015] The working principle of the utility model is as follows:

[0016] Start the electric pump, and ethylene glycol enters the storage tank from the input pipeline. Ethylene glycol is injected to meet the set height of the storage tank. The storage tank is a normal pressure container. Ethylene glycol flows from the output pipeline of the storage tank through the first ball valve, the flow meter and the PLC control system in sequence. The output flow of the injection pump is controlled in real time through the coordination of the PLC control system and the real-time output of the flow meter to control the injection amount. The pressure transmitter is used to monitor whether the output pressure of the injection pump meets the requirements to prevent the injection pump from outputting at ultra-high pressure. An overflow valve is provided at the outlet end of the injection pump. The ethylene glycol discharged after the overflow valve is tripped re-enters the flow meter and the injection pump through the outlet to form an injection cycle again. After the pressure relief is completed, the ethylene glycol is injected into the aerosol mixer through the high-pressure ball valve, the check valve and the high-sealing stop valve.

[0017] The beneficial effects of the utility model are as follows:

[0018] 1. In the utility model, the flow meter is connected to the PLC control system. The output flow of the injection pump is controlled in real time by coordinating the real-time output of the PLC control system and the flow meter to control the injection volume. The output pressure of the injection pump is monitored by the pressure transmitter to see if it meets the requirements. An overflow valve is provided at the outlet of the injection pump to prevent the injection pump from outputting at ultra-high pressure. The PLC control system is used in combination with the pressure transmitter, flow meter, and injection pump to jointly control the injection pressure and flow rate of ethylene glycol, so that the injection volume can be controlled, and the injection process is continuous and stable, ensuring work efficiency.

[0019] 2. In the utility model, a pressure transmitter and a pulse damper are also provided at one end of the injection pipeline near the overflow valve. The pressure transmitter is provided to monitor the output pressure of the injection pump, and the pulse damper eliminates the pressure pulsation caused by the continuous operation of the injection pump.

[0020] 3. In the utility model, two independent injection pipelines are connected to the output pipeline. One of the injection pipelines is in normal use, and the other is inactive. When one of the injection pipelines in use needs maintenance, the other injection pipeline is activated, or when the pipeline gas volume exceeds the design range, the two injection pipelines are opened at the same time to meet the working conditions.

[0021] 4. In the present invention, a liquid level remote transmitter is provided in the middle of the liquid level monitoring pipeline. The liquid level in the storage tank can be monitored in real time through the liquid level remote transmitter. If the liquid level is too low, a warning message is sent to prompt the addition of ethylene glycol. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the utility model.

[0023] Figure markings: 1-electric pump, 2-third ball valve, 3-pressure gauge and valve group, 4-breathing valve, 5-liquid level remote transmitter, 6-fourth ball valve, 7-drain valve, 8-storage tank, 9-second ball valve, 10-filter, 11-first ball valve, 12-flow meter, 13-injection pump, 14-outlet ball valve, 15-overflow valve, 16-pressure transmitter, 17-pulsation damper, 18-high-pressure ball valve, 19-sampling valve, 20-check valve, 21-high-sealing stop valve. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings of the utility model specification to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] Example 1

[0026] like Figure 1 As shown, a system suitable for injecting ethylene glycol into a wellhead pipeline includes a storage tank 8 and a PLC control system, characterized in that: the storage tank 8 is connected to an output pipeline, the output pipeline is connected to at least one injection pipeline, and a first ball valve 11, a flow meter 12, an injection pump 13, an overflow valve 15, a pressure transmitter 16, and an outlet ball valve 14 are arranged on the injection pipeline; the flow meter 12 and the injection pump 13 are respectively connected to the PLC control system, and ethylene glycol enters the injection pipeline through the output pipeline to form an injection circulation pipeline. If the injection pump 13 outputs at ultra-high pressure, the ethylene glycol discharged after the pressure is relieved by the overflow valve 15 re-enters the first ball valve 11, the flow meter 12, and the injection pump 13 through the outlet ball valve 14 to complete the injection cycle, and is transported to the next pipeline through the high-pressure ball valve 18.

[0027] As an implementation method of this embodiment, Figure 1 As shown, a pulse damper 17 and a sampling valve 19 are also provided on one end of the injection pipeline near the overflow valve 15. A pressure transmitter 16 is provided to monitor the output pressure of the injection pump 13. The pulse damper 17 eliminates the pressure pulsation caused by the continuous operation of the injection pump 13; the sampling valve 19 is used to take out the ethylene glycol sample in the injection pipeline.

[0028] During implementation, the electric pump 1 is started, and ethylene glycol enters the storage tank 8 from the input pipeline, and the ethylene glycol is injected to meet the set height of the storage tank 8. The storage tank 8 is a normal pressure container. The ethylene glycol flows from the output pipeline of the storage tank 8 through the first ball valve 11 and the flow meter 12 in sequence and is connected to the PLC control system. The output flow of the injection pump 13 is controlled in real time by the coordination of the real-time output of the PLC control system and the flow meter 12 to control the injection amount. The pressure transmitter 16 is used to monitor whether the output pressure of the injection pump 13 meets the requirements to prevent the injection pump 13 from outputting at an ultra-high pressure. The overflow valve 15 is provided at the outlet end of the injection pump 13. The ethylene glycol discharged after the overflow valve 15 is tripped re-enters the flow meter 12 and the injection pump 13 through the outlet to form an injection cycle again. When the pressure relief is completed, the ethylene glycol is injected and transported to the next pipeline through the high-pressure ball valve 18. The injection amount is controllable, and the injection process is continuous and stable, ensuring work efficiency.

[0029] Example 2

[0030] This embodiment further elaborates and supplements the implementation method of the utility model on the basis of Embodiment 1.

[0031] As another implementation method of this embodiment, Figure 1 As shown, the output pipeline is connected with two independent injection pipelines. During implementation, two injection pipelines are set, and the equipment on the two injection pipelines is exactly the same. One of the injection pipelines is in normal use, and the other injection pipeline is disabled. When one injection pipeline in use needs maintenance, the other injection pipeline is enabled, or when the pipeline gas volume exceeds the design range, the two injection pipelines will be opened at the same time to meet the working condition requirements.

[0032] Example 3

[0033] This embodiment further elaborates and supplements the implementation method of the utility model on the basis of Embodiment 1 or Embodiment 2.

[0034] As an implementation method of this embodiment, Figure 1 As shown, a check valve 20 and a high-seal stop valve 21 are provided at one end of the high-pressure ball valve 18. The check valve 20 is used to prevent the high-pressure gas from flowing back.

[0035] As another implementation of this embodiment, the output pipeline is provided with a second ball valve 9 and a filter 10, and ethylene glycol flows through the second ball valve 9 and the filter 10 in sequence and then enters the injection pipeline. The second ball valve 9 plays the role of opening and closing the injection pipeline. When the injection pipeline needs to be used, the second ball valve 9 is opened, and when it is not needed, the second ball valve 9 can be closed. The filter 10 is used to filter some impurities in the ethylene glycol to prevent affecting the subsequent mixing of the ethylene glycol and the high-pressure gas.

[0036] Example 4

[0037] This embodiment further elaborates and supplements the implementation method of the utility model on the basis of Embodiment 1, Embodiment 2 or Embodiment 3.

[0038] As an implementation method of this embodiment, Figure 1 As shown, a liquid level monitoring pipeline is provided on one side of the storage tank 8, and the two ends of the liquid level monitoring pipeline are respectively connected to the upper and lower ends of the storage tank 8, and a fourth ball valve 6 is provided at the connection point, and a liquid level remote transmitter 5 is provided in the middle of the liquid level monitoring pipeline. The liquid level in the storage tank 8 can be monitored in real time by the liquid level remote transmitter 5, and a warning message is sent to prompt the addition of ethylene glycol if the liquid level is too low.

[0039] As another implementation method of this embodiment, Figure 1 As shown, the storage tank 8 is connected to an input pipeline, the inlet end of the input pipeline is connected to an electric pump 1, and a third ball valve 2 is provided on the input pipeline. Ethylene glycol is injected into the storage tank 8 through the electric pump 1 to a set height of the storage tank 8.

[0040] As another implementation method of this embodiment, Figure 1 As shown, a pressure gauge and a valve group 3 are provided above the storage tank 8 for monitoring the pressure in the storage tank 8 , and a breathing valve 4 is used to isolate the air from direct contact with the liquid in the storage tank 8 .

[0041] As another implementation method of this embodiment, Figure 1 As shown, a sewage pipeline is arranged below the storage tank 8 and connected to the sewage pool. A sewage valve 7 is arranged on the sewage pipeline to discharge some impurities in the storage tank 8.

Claims

1. A system for injecting ethylene glycol into a wellhead pipeline, comprising a storage tank (8) and a PLC control system, characterized in that: The storage tank (8) is connected to an output pipeline, and the output pipeline is connected to at least one injection pipeline. The injection pipeline is provided with a first ball valve (11), a flow meter (12), an injection pump (13), a relief valve (15), a pressure transmitter (16), and an outlet ball valve (14). The flow meter (12) and the injection pump (13) are respectively connected to a PLC control system. Ethylene glycol enters the injection pipeline through the output pipeline to form an injection circulation pipeline. If the injection pump (13) outputs at an ultra-high pressure, the ethylene glycol discharged after the pressure is released by the relief valve (15) re-enters the first ball valve (11), the flow meter (12), and the injection pump (13) through the outlet ball valve (14) to complete the injection cycle, and is transported to the next pipeline through the high-pressure ball valve (18).

2. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 1, characterized in that: A pulse damper (17) and a sampling valve (19) are also provided on one end of the injection pipeline close to the pressure transmitter (16).

3. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 1 or 2, characterized in that: The output pipeline is connected with two independent injection pipelines.

4. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 3, characterized in that: A check valve (20) and a high-seal stop valve (21) are sequentially arranged at one end of the high-pressure ball valve (18).

5. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 4, characterized in that: The output pipeline is provided with a second ball valve (9) and a filter (10) in sequence, and ethylene glycol flows through the second ball valve (9) and the filter (10) in sequence before entering the injection pipeline.

6. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 3, characterized in that: A liquid level monitoring pipeline is provided on one side of the storage tank (8), the two ends of the liquid level monitoring pipeline are respectively connected to the upper and lower ends of the storage tank (8), and a fourth ball valve (6) is provided at the connection point, and a liquid level remote transmitter (5) is provided in the middle of the liquid level monitoring pipeline.

7. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 6, characterized in that: The storage tank (8) is connected to an input pipeline, the inlet end of the input pipeline is connected to an electric pump (1), and a third ball valve (2) is provided on the input pipeline. Ethylene glycol is injected into the storage tank (8) through the electric pump (1) to a set height of the storage tank (8).

8. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 7, characterized in that: A pressure gauge, a valve group (3) and a breathing valve (4) are arranged above the storage tank (8).

9. A system for injecting ethylene glycol into a wellhead pipeline as claimed in claim 8, characterized in that: A sewage discharge pipeline is provided below the storage tank (8) and is connected to a sewage discharge tank, and a sewage discharge valve (7) is provided on the sewage discharge pipeline.

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