Water attack pressure relief protection device and method based on original submarine pipeline old system

Abstract

The invention relates to a water attack pressure relief protection device and method based on an original submarine pipeline old system.The device comprises the original submarine pipeline old system and a newly-built system, and the original submarine pipeline old system comprises an underwater production system and a section of original submarine pipeline; the newly-built system comprises a main pipeline, a well drilling production platform and a release branch pipe, the inlet end of the main pipeline is in butt joint with a connector of an original submarine pipeline, and the outlet end of the main pipeline is in butt joint with the well drilling production platform. The well drilling production platform is provided with a buffer tank, and the buffer tank is communicated with the main pipeline through a discharge branch pipe; a water attack pressure release valve is arranged on the release branch pipe, and the opening pressure of the water attack pressure release valve is set according to the operating pressure design value in the original submarine pipeline; once the pressure in the original submarine pipeline reaches a running pressure design value, the water attack pressure relief valve is quickly opened, so that the material flow in the original submarine pipeline is discharged to the buffer tank through the discharge branch pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore oil engineering, in particular to a water hammer pressure relief protection device and method based on an original subsea pipeline old system. BACKGROUND

[0002] In the development of offshore oil and gas fields, as the existing oil field development enters the middle and later stages and new development projects are promoted, the situation that newly discovered oil fields need to be connected to existing production facilities is often encountered. Utilizing the original subsea pipeline old system can greatly save project investment, shorten the construction period and reduce environmental impact.

[0003] Among them, the original subsea pipeline old system includes an underwater production system, an original subsea pipeline and an offshore floating production system, wherein the underwater production system and the offshore floating production system are connected through the original subsea pipeline, as shown in Figure 1

[0004] However, the new production mode can cause the pipeline system to generate a water hammer pressure much higher than the original design pressure under abnormal operating conditions. This transient pressure peak can exceed the design pressure, test pressure or minimum yield pressure of the original subsea pipeline, posing a significant safety risk, making it technically infeasible to utilize the old subsea pipeline.

[0005] In summary, utilizing the current original subsea pipeline old system can easily cause the water hammer pressure in the original subsea pipeline to reach a peak, affecting the operation safety and not realizing the utilization of the subsea pipeline. SUMMARY

[0006] To solve the above problems, the present application provides a water hammer pressure relief protection device and method based on an original subsea pipeline old system, which can solve the problem of utilizing the current original subsea pipeline old system, which can easily cause the water hammer pressure in the original subsea pipeline to reach a peak, affecting the operation safety and not realizing the utilization of the subsea pipeline.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: The present application discloses a water hammer pressure relief protection device based on an original subsea pipeline old system, which comprises an original subsea pipeline old system and a new system, the original subsea pipeline old system comprises an underwater production system and a section of original subsea pipeline, one end of the original subsea pipeline is connected to the underwater production system, and the other end has an interface, the new system comprises a main pipeline, a drilling production platform and a relief branch pipe, the inlet end of the main pipeline is connected to the interface of the original subsea pipeline, and the outlet end of the main pipeline is connected to the drilling production platform; a buffer tank is arranged on the drilling production platform, and the buffer tank is communicated with the main pipeline through the relief branch pipe; ​The water hammer pressure relief valve is arranged on the blow-off branch pipe, wherein the opening pressure of the water hammer pressure relief valve is set according to the operating pressure design value in the original submarine pipeline, and the operating pressure design value in the original submarine pipeline is closely related to the water hammer pressure peak value in the original submarine pipeline. Once the pressure in the original submarine pipeline reaches the operating pressure design value, the water hammer pressure relief valve is rapidly opened to discharge the flow in the original submarine pipeline to the buffer tank through the blow-off branch pipe.

[0008] Further, the water hammer pressure relief valve is provided with a pressure gauge arranged on the original submarine pipeline or the main pipeline, which can monitor the pressure in the original submarine pipeline or the main pipeline in real time. The pressure gauge and the water hammer pressure relief valve are connected by wire, and the water hammer pressure relief valve determines whether the pressure in the original submarine pipeline reaches the operating pressure design value according to the pressure gauge.

[0009] Further, the opening pressure of the water hammer pressure relief valve is lower than the operating pressure design value in the original submarine pipeline.

[0010] Further, a platform shut-off valve is arranged on the main pipeline between the connection of the blow-off branch pipe and the main pipeline and the drilling production platform.

[0011] Further, the blow-off branch pipe comprises a marine riser pipe installed on the drilling production platform, and the water hammer pressure relief valve is installed at the top end of the marine riser pipe.

[0012] Further, the water hammer pressure relief valve is a rapid opening valve, and the response time thereof should be less than or equal to 0.1 s.

[0013] Further, the water hammer pressure relief valve is a pneumatic control valve.

[0014] Further, the water hammer pressure relief valve is a nitrogen type water hammer pressure relief valve.

[0015] In the second aspect, the application further discloses a water hammer pressure relief protection method based on an original submarine pipeline old system, which adopts the water hammer pressure relief protection device based on the original submarine pipeline old system. Once the pressure in the original submarine pipeline reaches the operating pressure design value, the water hammer pressure relief valve is rapidly opened to discharge the flow in the original submarine pipeline to the buffer tank through the blow-off branch pipe. After the water hammer pressure in the original submarine pipeline is reduced to below the operating pressure design value, the water hammer pressure relief valve is automatically closed to restore the normal pipeline conveying state. If the connection between the subsea production system and the drilling production platform is interrupted, the pressure wave in the original subsea pipeline will propagate downstream to the main pipeline and the venting branch, increasing the pressure passing through the water hammer pressure relief valve. During this period, the pressure gauge installed on the original subsea pipeline or the main pipeline monitors the pressure in the original subsea pipeline or the main pipeline in real time, and the water hammer pressure relief valve determines whether the pressure in the original subsea pipeline has reached the design operating pressure value based on the pressure gauge.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention discloses a water hammer pressure relief protection device based on an existing subsea pipeline system, comprising the existing subsea pipeline system and a newly constructed system. The existing subsea pipeline system includes an underwater production system and a section of the existing subsea pipeline. One end of the existing subsea pipeline is connected to the underwater production system, and the other end has an interface. The newly constructed system includes a main pipeline, a drilling production platform, and a discharge branch pipe. The inlet end of the main pipeline is connected to the interface of the existing subsea pipeline, and the outlet end of the main pipeline is connected to the drilling production platform. A buffer tank is installed on the drilling production platform, and the buffer tank is connected to the main pipeline through the discharge branch pipe. A water hammer pressure relief valve is installed on the discharge branch pipe, wherein the opening pressure of the water hammer pressure relief valve is set according to the design value of the operating pressure in the existing subsea pipeline, and the design value of the operating pressure in the existing subsea pipeline is closely related to the peak value of the water hammer pressure in the existing subsea pipeline. Once the pressure in the existing subsea pipeline reaches the design value of the operating pressure, the water hammer pressure relief valve opens rapidly, allowing the material in the existing subsea pipeline to be discharged to the buffer tank through the discharge branch pipe. This invention discloses a water hammer pressure relief protection device based on an existing subsea pipeline system. Without modifying the existing subsea pipeline, it effectively suppresses water hammer pressure peaks through a rapid release mechanism, thereby achieving safe and economical reuse of the existing subsea pipeline.

[0017] Furthermore, the present invention also has the following advantages: High safety: It fundamentally solves the biggest obstacle to reusing existing infrastructure—water hammer and overpressure—by forcibly limiting transient pressure within a safe range, ensuring the integrity of the pipeline.

[0018] Good economic efficiency: It avoids the huge cost of replacing the entire subsea pipeline and does not require large-scale physical modification of the existing subsea pipeline, which greatly reduces the total investment of the project and the difficulty of offshore construction, and reduces economic and construction risks.

[0019] Easy to implement: The main equipment is installed and debugged on the newly built platform, eliminating the need for expensive and high-risk underwater operations.

[0020] Rapid response: Specifically designed to address the rapid rise in water hammer pressure, a quick-opening pressure relief valve is selected, providing significantly better protection than traditional safety valves.

[0021] Environmentally friendly: The leaked medium is directed to the buffer tank, which meets safety and environmental protection requirements. Attached Figure Description

[0022] Figure 1 This is a structural diagram of the existing submarine pipeline system provided by current technology; Figure 2 This is a schematic diagram of the structure of the water hammer pressure relief protection device based on the original old submarine pipeline system provided in Embodiment 1 of the present invention.

[0023] Explanation of reference numerals in the attached diagram: 100 - Existing subsea pipeline; 101 - Interface; 1-Main pipeline, 10-Platform shut-off valve; 2- Drilling production platform, 20- Buffer tank; 3-Discharge branch pipe, 30-Water hammer pressure relief valve. Detailed Implementation

[0024] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0025] Example 1: A water hammer relief protection device based on an existing subsea pipeline system Embodiment 1 of the present invention provides a water hammer pressure relief protection device based on the existing old submarine pipeline system. Its structure is described in detail below.

[0026] refer to Figure 2 The water hammer relief protection device based on the existing subsea pipeline system includes both the existing subsea pipeline system and the newly built system. The existing subsea pipeline system includes an underwater production system and an existing subsea pipeline 100. One end of the existing subsea pipeline 100 is connected to the underwater production system, and the other end has an interface 101. The existing subsea pipeline 100 includes an existing underwater manifold, and the interface 101 is reserved at the outer end of the existing subsea pipeline 100. The newly constructed system includes a main pipeline 1, a drilling production platform 2, and a venting branch pipe 3. The inlet end of the main pipeline 1 is connected to the interface 101 of the existing subsea pipeline 100, so that the inlet end of the main pipeline 1 is connected to the underwater production system through the existing subsea pipeline 100, and the outlet end of the main pipeline 1 is connected to the drilling production platform 2. The drilling production platform 2 is equipped with a buffer tank 20, which is connected to the main pipeline 1 through a discharge branch pipe 3. The discharge branch pipe 3 is equipped with a water hammer pressure relief valve 30, wherein the opening pressure P0 of the water hammer pressure relief valve 30 is set according to the design value of the operating pressure in the original submarine pipeline 100, and the design value of the operating pressure in the original submarine pipeline 100 is closely related to the peak value of the water hammer pressure in the original submarine pipeline 100. Once the pressure inside the existing subsea pipeline 100 reaches the design operating pressure, the water hammer pressure relief valve 30 opens rapidly, allowing the material inside the existing subsea pipeline 100 to be discharged into the buffer tank 20 through the discharge branch pipe 3.

[0027] Specifically, the water hammer pressure relief valve 30 is equipped with a pressure gauge, which is installed on the original submarine pipeline 100 or the main pipeline 1, and can monitor the pressure inside the original submarine pipeline 100 or the main pipeline 1 in real time. The pressure gauge is connected to the water hammer pressure relief valve 30 via a wire. The water hammer pressure relief valve 30 uses the pressure gauge to determine whether the pressure inside the original subsea pipeline 100 has reached the design operating pressure value.

[0028] The design value of the operating pressure within the original subsea pipeline 100 is determined based on the actual operating conditions of the original subsea pipeline 100.

[0029] Specifically, in order to protect the pressure within the existing subsea pipeline 100, the opening pressure P0 of the water hammer pressure relief valve 30 is lower than the design operating pressure value within the existing subsea pipeline 100. For example, suppose the maximum allowable pressure value within the existing subsea pipeline 100 is P. max-1 Based on the maximum pressure value P that the existing submarine pipeline 100 can withstand. max-1 The opening pressure P0 of the water hammer relief valve 30 is set. This is to ensure that the pressure within the existing subsea pipeline 100 reaches P. max-1 Previously, the water hammer relief valve 30 was opened. Let P be the maximum allowable pressure within the existing subsea pipeline 100. max-1 The opening pressure P0 of the water hammer relief valve 30 is: P0 = kP max-1 If k∈(0,1), then k∈(0,1).

[0030] To ensure that the pressure in the venting branch pipe 3 reaches the opening pressure P0 of the water hammer relief valve 30, and that both the main pipeline 1 and the venting branch pipe 3 remain in a safe state, the maximum permissible pressure in the main pipeline 1 and the venting branch pipe 3 is higher than the opening pressure P0 of the water hammer relief valve 30. Generally, to ensure the advanced nature of the new system, the maximum permissible pressure in the pipelines of the new system will be greater than the maximum permissible pressure in the pipelines of the existing submarine pipeline system, that is, the maximum permissible pressure value P2 in the main pipeline 1 and the venting branch pipe 3 is greater than the design operating pressure value P1 in the existing submarine pipeline 100.

[0031] In summary, the relationship between the maximum allowable pressure P2 in the main pipeline 1 and the discharge branch pipe 3, the design operating pressure P1 in the original submarine pipeline 100, and the opening pressure P0 of the water hammer relief valve 30 is: P2 > P1 > P0.

[0032] To facilitate control of the water hammer pressure relief valve 30, the relief branch pipe 3 includes a subsea pipeline riser, which is installed on the drilling production platform 2, and the water hammer pressure relief valve 30 is installed at the top of the subsea pipeline riser.

[0033] Specifically, the water hammer pressure relief valve 30 is a quick-opening valve, and its response time should be less than or equal to 0.1s.

[0034] To accommodate the rapid rise in water hammer pressure, the water hammer relief valve 30 is a pneumatically controlled valve.

[0035] Preferably, the water hammer pressure relief valve 30 is a nitrogen-type water hammer pressure relief valve.

[0036] In one specific implementation, the original submarine pipeline 100 is approximately 10.44 km long.

[0037] In order to cut off the connection between the underwater production system and the drilling production platform 2 according to the actual working conditions, a platform shut-off valve 10 is installed on the main pipeline 1 between the connection between the discharge branch pipe 3 and the main pipeline 1 and the drilling production platform 2.

[0038] Specifically, a platform shut-off valve 10 is installed on the main pipeline near the drilling production platform 2, such that the platform shut-off valve 10 is located upstream of the discharge branch pipe 3 on the main pipeline 1.

[0039] When the fluid reaches the vent branch pipe 3, the pressure rises rapidly, reaching a pressure value associated with the design operating pressure of the original subsea pipeline 100. The water hammer relief valve 5 opens rapidly within tens of milliseconds, quickly releasing the high-pressure oil-gas mixture to the low-pressure buffer tank 20. This release action is equivalent to opening a gap in the pressure wave, effectively absorbing and weakening the water hammer energy, thereby successfully limiting the maximum pressure within the original subsea pipeline 100 to below 7050 kPaA, meeting the pressure requirements of the old pipeline and allowing it to be safely reused.

[0040] Transient simulation software verification revealed that the maximum allowable pressure value P within 100 meters of the original subsea pipeline was within acceptable limits. max-1 The initial design pressure is 7600 kPaA. Under the new reconnection conditions, the peak water hammer pressure generated by emergency shutdown can reach 8250 kPaA, exceeding the original subsea pipeline design pressure. The water hammer relief valve 30 is a pneumatic quick-opening valve with a set opening pressure of 7050 kPaA.

[0041] Example 2: A method for water hammer pressure relief protection based on an existing subsea pipeline system Embodiment 2 of the present invention provides a water hammer pressure relief protection method based on an existing subsea pipeline system, using the water hammer pressure relief protection device based on an existing subsea pipeline system provided in Embodiment 1. The method includes the following steps: Once the pressure inside the original subsea pipeline 100 reaches the design operating pressure value, the water hammer pressure relief valve 30 opens rapidly, allowing the material inside the original subsea pipeline 100 to be discharged into the buffer tank 20 through the discharge branch pipe 3. Once the water hammer pressure inside the original submarine pipeline 100 drops below the design operating pressure, the water hammer relief valve 30 will automatically close, restoring the pipeline to normal transport status. Specifically, if the connection between the subsea production system and the drilling production platform 2 is cut off, the pressure wave in the original subsea pipeline 100 will propagate downstream to the main pipeline 1 and the discharge branch pipe 3, pushing up the pressure passing through the water hammer pressure relief valve 30. During this period, the pressure gauge installed on the original subsea pipeline 100 or the main pipeline 1 monitors the pressure in the original subsea pipeline 100 or the main pipeline 1 in real time, and the water hammer pressure relief valve 30 determines whether the pressure in the original subsea pipeline 100 has reached the design value of the operating pressure based on the pressure gauge.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water hammer relief protection device based on an existing subsea pipeline system, comprising the existing subsea pipeline system, wherein the existing subsea pipeline system includes an underwater production system and a section of the existing subsea pipeline (100), one end of the existing subsea pipeline (100) is connected to the underwater production system, and the other end has an interface (101), characterized in that, It also includes a new system, which includes a main pipeline (1), a drilling production platform (2), and a venting branch pipe (3). The inlet end of the main pipeline (1) is connected to the interface (101) of the original subsea pipeline (100), and the outlet end of the main pipeline (1) is connected to the drilling production platform (2). The drilling production platform (2) is equipped with a buffer tank (20), which is connected to the main pipeline (1) through a discharge branch pipe (3); The discharge branch pipe (3) is equipped with a water hammer pressure relief valve (30), wherein the opening pressure of the water hammer pressure relief valve (30) is set according to the design value of the operating pressure in the original submarine pipeline (100), and the design value of the operating pressure in the original submarine pipeline (100) is closely related to the peak value of the water hammer pressure in the original submarine pipeline (100). Once the pressure inside the existing subsea pipeline (100) reaches the design operating pressure, the water hammer relief valve (30) opens rapidly, allowing the material inside the existing subsea pipeline (100) to be discharged into the buffer tank (20) through the discharge branch pipe (3).

2. The water hammer pressure relief protection device based on the existing submarine pipeline system according to claim 1, characterized in that, The water hammer pressure relief valve (30) is equipped with a pressure gauge, which is installed on the original submarine pipeline (100) or main pipeline (1) and can monitor the pressure in the original submarine pipeline (100) or main pipeline (1) in real time. The pressure gauge is connected to the water hammer pressure relief valve (30) by wire. The water hammer pressure relief valve (30) determines whether the pressure in the original submarine pipeline (100) has reached the design value of the operating pressure based on the pressure gauge.

3. The water hammer relief protection device based on the existing submarine pipeline system according to claim 2, characterized in that, The opening pressure of the water hammer relief valve (30) is lower than the design operating pressure value in the original submarine pipeline (100).

4. The water hammer relief protection device based on the existing submarine pipeline system according to claim 1, characterized in that, A platform shut-off valve (10) is installed on the main pipeline (1) between the connection point of the discharge branch pipe (3) and the main pipeline (1) and the drilling production platform (2).

5. The water hammer pressure relief protection device based on the existing submarine pipeline system according to claim 1, characterized in that, The venting branch pipe (3) includes a subsea pipeline riser, which is installed on the drilling production platform (2), and the water hammer relief valve (30) is installed at the top of the subsea pipeline riser.

6. The water hammer relief protection device based on the existing submarine pipeline system according to claim 1, characterized in that, The water hammer relief valve (30) is a fast-opening valve, and its response time should be less than or equal to 0.1s.

7. The water hammer relief protection device based on the existing submarine pipeline system according to claim 6, characterized in that, The water hammer pressure relief valve (30) is a pneumatic control valve.

8. The water hammer relief protection device based on the existing submarine pipeline system according to claim 7, characterized in that, The water hammer pressure relief valve (30) is a nitrogen-type water hammer pressure relief valve.

9. A method for water hammer pressure relief protection based on an existing subsea pipeline system, comprising the water hammer pressure relief protection device based on any one of claims 1 to 8, characterized in that, include Once the pressure inside the original subsea pipeline (100) reaches the design value of the operating pressure, the water hammer relief valve (30) opens quickly, allowing the material inside the original subsea pipeline (100) to be discharged into the buffer tank (20) through the discharge branch pipe (3). Once the water hammer pressure in the original submarine pipeline (100) drops below the design operating pressure, the water hammer relief valve (30) will automatically close, restoring the pipeline to normal transport status.

10. The water hammer pressure relief protection method based on the existing subsea pipeline system according to claim 9, characterized in that, If the connection between the subsea production system and the drilling production platform (2) is cut off, the pressure wave in the original subsea pipeline (100) will propagate to the downstream main pipeline (1) and the discharge branch pipe (3), pushing up the pressure passing through the water hammer pressure relief valve (30). During this period, the pressure gauge installed on the original subsea pipeline (100) or the main pipeline (1) monitors the pressure in the original subsea pipeline (100) or the main pipeline (1) in real time, and the water hammer pressure relief valve (30) determines whether the pressure in the original subsea pipeline (100) has reached the design value of the operating pressure based on the pressure gauge.

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