An underwater monitoring sampling device for draining, drying and inerting a subsea pipeline

Abstract

The application discloses a kind of submarine pipeline drainage, dry and inertization underwater monitoring sampling device, it is related to marine engineering technical field, connect to submarine pipeline, the first end interface of pressure monitoring nipple is connected to submarine pipeline, the last end interface of pressure monitoring nipple connects the first end interface of flow monitoring nipple, the first end interface of sampling monitoring nipple is connected to the last end interface of flow monitoring nipple by one-way valve, the last end interface of sampling monitoring nipple is connected to the first end interface of spare sampling monitoring nipple by one-way valve, the last end interface of spare sampling monitoring nipple connects one end of flow regulating valve, the other end of flow regulating valve connects elbow nipple group, and elbow nipple group can adjust connection direction to control discharge angle.The device is suitable for monitoring and sampling of the drainage, drying and inertization construction of submarine pipeline after laying, which is entirely located underwater, avoids the influence of sea waves, and the construction is safer and more efficient.

Description

Technical Field

[0001] This invention relates to the field of marine oil engineering technology, and more particularly to an underwater monitoring and sampling device for draining, drying, and inerting subsea pipelines. Background Technology

[0002] Subsea pipelines are the lifeblood of offshore oil and gas field development and operation, responsible for transporting oil and gas media. After being laid at sea, subsea pipelines require a series of commissioning work to be ready for oil and gas transportation. These mainly include pipeline cleaning and pressure tightness testing. Pipelines transporting gas usually also need to undergo drainage, drying, and inerting processes to ensure that the subsea pipeline can safely and stably transport media after it is put into operation.

[0003] With the continuous development of offshore oil and gas fields in my country, more and more subsea pipelines are being installed entirely underwater, and the water depth is gradually increasing from 300 meters to 1500-2000 meters. These fully submerged pipelines present significant challenges to commissioning. Subsea pipeline dewatering utilizes compressed air or nitrogen as the driving medium, with a drain pig acting as a gas-water separator to ultimately remove water from the pipeline. Subsea pipeline drying uses low-dew-point dry air, nitrogen, or a desiccant to displace the humid air inside the pipeline. Subsea pipeline inerting uses nitrogen with a concentration exceeding 95% to expel air or water from the pipeline, ultimately filling the pipeline with nitrogen. This ensures that oil and gas entering the pipeline are not within the explosive limits of flammable gases, guaranteeing safe oil and gas transportation. Subsea pipeline dewatering, drying, and inerting require monitoring and sampling parameters such as the flow rate, pressure, nitrogen concentration, and dew point at the pipeline's discharge end.

[0004] However, current monitoring and sampling of drainage, drying, and inerting parameters for subsea pipelines are mostly carried out through pipelines above the water surface. There is currently no safe, efficient, and convenient device for monitoring and sampling of drainage, drying, and inerting parameters for subsea pipelines that are entirely underwater. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a device capable of monitoring and sampling the drainage, drying and inerting parameters of underwater subsea pipelines.

[0006] To address the aforementioned technical problems, this invention provides an underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines. Connected to the subsea pipeline, the device includes a pressure monitoring sub-section, a flow monitoring sub-section, a sampling monitoring sub-section, a backup sampling monitoring sub-section, a flow regulating valve, and an elbow sub-section assembly. The first end of the pressure monitoring sub-section is connected to the subsea pipeline, and the last end of the pressure monitoring sub-section is connected to the first end of the flow monitoring sub-section. The first end of the sampling monitoring sub-section is connected to the last end of the flow monitoring sub-section via a one-way valve. The last end of the sampling monitoring sub-section is connected to the first end of the backup sampling monitoring sub-section via a one-way valve. The last end of the backup sampling monitoring sub-section is connected to one end of the flow regulating valve, and the other end of the flow regulating valve is connected to the elbow sub-section assembly. The elbow sub-section assembly can be adjusted in direction to control the discharge angle.

[0007] According to a preferred embodiment of the present invention, a pressure isolation valve is installed at one end of the pressure monitoring subsection, and a pressure gauge is connected to the other end of the pressure isolation valve.

[0008] According to a preferred embodiment of the present invention, a flow meter is installed on the flow monitoring section.

[0009] According to a preferred embodiment of the present invention, two sampling isolation valves are installed on the sampling monitoring section, each sampling isolation valve is connected to the head end of a sampling check valve, and the tail end of the sampling check valve is connected to a nitrogen concentration and dew point measuring instrument.

[0010] According to a preferred embodiment of the present invention, two isolation valve groups are installed on the standby sampling monitoring section, and each isolation valve group includes two isolation valves connected in series.

[0011] According to a preferred embodiment of the present invention, the end interface of the pressure monitoring sub and the beginning interface of the flow monitoring sub are connected by bolts.

[0012] According to a preferred embodiment of the present invention, the elbow section assembly includes two or more elbow sections, which are connected end to end in sequence.

[0013] The technical advantages of this invention are as follows: 1. This invention provides an underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines. During construction, the fluid discharged from the subsea pipeline passes sequentially through a pressure monitoring section, a flow monitoring section, and a sampling monitoring section. Key parameters such as fluid pressure, flow rate, nitrogen concentration, and gas dew point are obtained. By monitoring the data in real time, the construction progress of drainage, drying, and inerting of the subsea pipeline can be understood, and it can be determined whether the design requirements have been met. This achieves the beneficial effect of monitoring and sampling the drainage, drying, and inerting parameters of subsea pipelines located underwater.

[0014] 2. This invention provides an underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines. It is suitable for monitoring and sampling during the drainage, drying, and inerting processes of subsea pipelines that are entirely underwater after laying. The sampling and measurement are performed underwater, avoiding the influence of waves, making the construction safer and more efficient. It can meet the testing requirements of deep-water subsea pipelines in the South China Sea and provides technical support for the development of deep-water oil and gas fields. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an underwater monitoring and sampling device for drainage, drying and inerting of a subsea pipeline according to the present invention; Figure 2 This is a schematic diagram of the underwater connection of an underwater monitoring and sampling device for drainage, drying, and inerting of a subsea pipeline according to the present invention.

[0016] Reference numerals: 1-Pressure monitoring sub-section; 2-Flow monitoring sub-section; 3-Check valve; 4-Sampling monitoring sub-section; 5-Spare sampling monitoring sub-section; 6-Flow regulating valve; 7-Elbow sub-section; 11-Pressure isolation valve; 12-Pressure gauge; 21-Flow meter; 41-Sampling isolation valve; 42-Sampling check valve; 43-Nitrogen concentration and dew point measuring instrument; 51-Isolation valve; 8-Subsea pipeline. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the invention.

[0018] like Figure 1 and Figure 2 As shown, an underwater monitoring and sampling device for drainage, drying, and inerting of a subsea pipeline is connected to a subsea pipeline 8. It includes a pressure monitoring sub-section 1, a flow monitoring sub-section 2, a sampling monitoring sub-section 4, a backup sampling monitoring sub-section 5, a flow regulating valve 6, and an elbow sub-section assembly. The first end of the pressure monitoring sub-section 1 is connected to the subsea pipeline 8, and the last end of the pressure monitoring sub-section 1 is connected to the first end of the flow monitoring sub-section 2. The first end of the sampling monitoring sub-section 4 is connected to the last end of the flow monitoring sub-section 2 via a one-way valve 3. The last end of the sampling monitoring sub-section 4 is connected to the first end of the backup sampling monitoring sub-section 5 via a one-way valve 3. The last end of the backup sampling monitoring sub-section 5 is connected to one end of the flow regulating valve 6, and the other end of the flow regulating valve 6 is connected to the elbow sub-section assembly. The elbow sub-section assembly can be adjusted in direction to control the discharge angle.

[0019] This invention discloses an underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines. The device's inlet is connected to the terminal of the subsea pipeline 8. During construction, the fluid discharged from the subsea pipeline 8 sequentially passes through a pressure monitoring section 1, a flow monitoring section 2, and a sampling monitoring section 4. Key parameters such as the fluid pressure, flow rate, nitrogen concentration, and gas dew point are obtained. Real-time monitoring data allows for understanding the progress of drainage, drying, and inerting of the subsea pipeline 8 and determining whether the design requirements have been met. This sampling device is suitable for monitoring and sampling during the drainage, drying, and inerting construction of subsea pipelines 8 that are entirely underwater after installation. Furthermore, the underwater sampling and measurement avoids the influence of waves, making construction safer and more efficient.

[0020] Preferably, the interface of the pressure monitoring subsection 1 is used to connect to the subsea pipeline 8. During drainage, drying and inerting construction, the fluid in the pipeline is discharged through the terminal of the subsea pipeline 8. The pressure monitoring subsection 1 is equipped with a pressure isolation valve 11 and a pressure gauge 12 to monitor the pressure parameters of the fluid discharged from the subsea pipeline 8.

[0021] Preferably, the flow monitoring section 2 is installed at the rear end of the pressure monitoring section 1, and the two are connected by bolts. A flow meter 21 is installed on the flow monitoring section 2 to monitor the flow rate data of the discharged fluid.

[0022] Preferably, the one-way valve 3 is installed on both sides of the sampling and monitoring section 4, and the one-way valve 3 prevents seawater from entering the subsea pipeline 8.

[0023] Preferably, the sampling monitoring section 4 is equipped with a sampling isolation valve 41, a sampling check valve 42, and a nitrogen concentration and dew point meter 43. When sampling is not required, the sampling isolation valve 41 can be closed, and the nitrogen concentration and dew point meter 43 can measure the nitrogen concentration value and the dew point value of the gas, thereby determining whether the drainage, drying and inerting effects of the subsea pipeline 8 meet the design requirements.

[0024] Preferably, the standby sampling and monitoring manifold 5 is equipped with two isolation valve groups, each of which includes two isolation valves 51 connected in series. When the nitrogen concentration and dew point measuring instrument 53 on the sampling and monitoring manifold fails during the underwater use phase, a hose can be lowered from the construction vessel and connected to the interface of the standby sampling and monitoring manifold 5 to transport fluid to the ship's deck for sampling and parameter measurement.

[0025] Preferably, the flow regulating valve 6 is located after the standby sampling and monitoring section 5, and is used to regulate the flow rate of the fluid discharged from the subsea pipeline 8 during construction, thereby controlling the flow rate within a reasonable range.

[0026] Preferably, the elbow short section assembly is installed after the flow regulating valve 6 to adjust the direction of fluid discharge. It can also be connected to an extension pipeline to extend the fluid discharged from the subsea pipeline 8 to a more distant location, making underwater construction safer. The elbow short section assembly includes two or more elbow short sections 7, which are connected end to end in sequence.

[0027] like Figure 1 As shown, an underwater monitoring and sampling device for drainage, drying, and inerting of a subsea pipeline includes a pressure monitoring section 1 with connection ports at both ends. The upstream port connects to the terminal of the subsea pipeline 8, and the downstream port connects to a flow monitoring section 2. A pressure isolation valve 11 and a pressure gauge 12 are installed on the pressure monitoring section 1. When fluid flows from the terminal of the subsea pipeline 8 into the pressure monitoring section 1, the pressure value of the fluid is measured, displayed, and recorded by the pressure gauge 12. When monitoring the fluid pressure parameter is not required, the pressure isolation valve 11 can be closed. Fluid flows from the pressure monitoring section 1 into the flow monitoring section 2, where a flow meter 21 is arranged to measure, display, and record the flow rate parameter of the fluid flowing through it. Fluid flows from the flow monitoring section 2 into a one-way valve 3, which allows fluid to flow in only one direction: from the flow monitoring section 2 to the sampling monitoring section 4, and from the sampling monitoring section 4 to the standby sampling monitoring section 5. The sampling section 4 is equipped with a sampling isolation valve 41, a sampling check valve 42, and a nitrogen concentration and dew point measuring instrument 43. When nitrogen concentration and gas dew point need to be measured, the sampling isolation valve 41 is opened to begin parameter measurement. If the instrument on the sampling monitoring section malfunctions, the backup sampling monitoring section 5 can be used for sampling and parameter measurement. The backup sampling monitoring section 5 is equipped with two isolation valves 51, which are connected to the outlet of the backup sampling monitoring section 5 via a hose lowered from the construction vessel. When connecting the pipeline, the isolation valves 51 need to be closed. After the connection is completed, the isolation valves 51 are opened, and the fluid is delivered to the ship's deck via the lowering hose. The deck personnel use conventional instruments to detect the nitrogen concentration and gas dew point. The fluid enters the flow regulating valve 6 through the backup sampling monitoring section 5. The flow regulating valve 6 can be adjusted underwater by an underwater robot or diver to control the flow rate of the discharged fluid. The fluid then enters the elbow section 7 through the flow regulating valve 6 and is discharged into the seawater. Elbow section 7 can adjust the connection direction to control the discharge angle of the discharged fluid, thereby ensuring the safety of underwater robots or divers and preventing impact from the discharged fluid. At the same time, elbow section 7 can also be connected to underwater pipelines to extend the discharged fluid to a more distant area, ensuring construction safety.

[0028] like Figure 2As shown, during the drainage, drying, and inerting operations of newly laid subsea pipeline systems, compressed air or nitrogen is typically used to drain the water from the subsea pipeline 8. This device is connected to the terminal of the subsea pipeline 8. After the fluid is discharged from the terminal of the subsea pipeline 8, it enters the underwater monitoring and sampling device. It sequentially passes through pressure monitoring section 1 to measure and display the pressure parameters of the stored fluid, through flow monitoring section 2 to measure and display the flow parameters of the stored fluid, and through check valve 3 to enter sampling monitoring section 4 to sample the fluid and measure the nitrogen concentration and gas dew point parameters. The fluid then enters the backup sampling monitoring section 5, where the flow rate can be adjusted via flow regulating valve 6. The fluid is then discharged into the seawater through elbow section 7. The backup sampling monitoring section 5 will be used in case the instruments on sampling monitoring section 4 malfunction.

[0029] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. An underwater monitoring and sampling device for drainage, drying, and inerting of a subsea pipeline, connected to the subsea pipeline, comprising a pressure monitoring subsection, a flow monitoring subsection, a sampling monitoring subsection, a spare sampling monitoring subsection, a flow regulating valve, and an elbow subsection assembly, characterized in that, The first end interface of the pressure monitoring subsection is connected to the subsea pipeline, the last end interface of the pressure monitoring subsection is connected to the first end interface of the flow monitoring subsection, the first end interface of the sampling monitoring subsection is connected to the last end interface of the flow monitoring subsection via a one-way valve, the last end interface of the sampling monitoring subsection is connected to the first end interface of the spare sampling monitoring subsection via a one-way valve, the last end interface of the spare sampling monitoring subsection is connected to one end of the flow regulating valve, and the other end of the flow regulating valve is connected to the elbow subsection assembly, the elbow subsection assembly can be adjusted in connection direction to control the discharge angle; The sampling monitoring section is equipped with two sampling isolation valves, each of which is connected to the head end of a sampling check valve. The tail end of the sampling check valve is connected to a nitrogen concentration and dew point measuring instrument. The spare sampling monitoring section is equipped with two isolation valve groups, each of which includes two isolation valves connected in series. The elbow section assembly includes two or more elbow sections, which are connected end to end in sequence.

2. The underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines according to claim 1, characterized in that, One end of the pressure monitoring section is equipped with a pressure isolation valve, and the other end of the pressure isolation valve is connected to a pressure gauge.

3. The underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines according to claim 1, characterized in that, A flow meter is installed on the flow monitoring section.

4. The underwater monitoring and sampling device for drainage, drying, and inerting of subsea pipelines according to claim 1, characterized in that, The end interface of the pressure monitoring section and the beginning interface of the flow monitoring section are connected by bolts.

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