Liquid collecting device and marine flexible pipeline annulus internal seepage accumulated liquid discharging control device and method

Abstract

The invention relates to a liquid collection device and a marine flexible pipeline annulus internal seepage accumulated liquid control and discharge device and method.The device comprises a liquid suction box, a hydraulic oil tank and a two-way pump, when the two-way pump rotates in the forward direction, the two-way pump conveys hydraulic oil of a hydraulic oil part of the liquid suction box into the hydraulic oil tank, and the hydraulic oil of the liquid suction box promotes a partition plate to move upwards; negative pressure is formed on the liquid seepage and accumulation part, so that seepage and accumulation liquid can be sucked into a liquid inlet of the liquid seepage and accumulation part; meanwhile, the hydraulic oil in the hydraulic oil tank is increased accordingly, and the hydraulic oil gets close to the steering switch under the action of self weight until touching the steering switch; when the two-way pump rotates reversely, the two-way pump conveys hydraulic oil in the hydraulic oil tank into the hydraulic oil part of the liquid suction tank reversely, the hydraulic oil in the hydraulic oil part of the liquid suction tank is increased, the partition plate is pushed to descend, then the liquid seepage and accumulation part of the liquid suction tank is compressed, and seepage and accumulation liquid in the liquid seepage and accumulation part of the liquid suction tank is promoted to flow out of the liquid outlet. And the partition plate descends and touches the limiting switch.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ocean engineering, in particular to a liquid collecting device and a device and method for controlling and discharging accumulated liquid in the annulus of a marine flexible pipe. BACKGROUND

[0002] Deepwater oil and gas resources are the focus of future global oil and gas exploration and development, and are of great significance to improving China's oil and gas production and ensuring energy security. The marine pipeline is the lifeline of offshore oil and gas transportation, and the marine flexible pipe is the most critical link for oil and gas resources from the underwater to the platform.

[0003] The marine flexible pipe is usually used to connect the wellhead or manifold with the offshore drilling and production platform. Compared with the traditional steel pipe, the multi-layer composite structure of the flexible pipe has the advantages of strong designability, high flexibility, and good economy (20%~50% lower overall cost). Due to the gas permeation characteristics of the polymer material inside the flexible pipe, small molecule gases (such as water and carbon dioxide) in the pipe will penetrate through the internal pressure sealing layer to the annulus (the annular space between the inner liner and the outer protective layer), and accumulate to form accumulated liquid in the annulus. Acidic gases such as CO2 and H2S form acid corrosion with water. For deepwater, the high-pressure and low-temperature environment at the bottom of the riser pipe can also form hydrates, which will pose a risk to the strength and safety of the pipe, and in severe cases may cause pipe failure and rupture. Therefore, controlling and removing the accumulated liquid in the annulus of the flexible riser pipe is of great significance to ensuring the safe and efficient production of offshore oil and gas fields and maintaining national energy security.

[0004] Currently, the research on marine flexible pipes mainly focuses on the mechanical properties such as riser vortex vibration, bearing capacity, and fatigue, and the research on accumulated liquid in the annulus of the flexible riser pipe is still in its infancy. Currently, the discharge of accumulated liquid in the annulus of the marine flexible pipe cannot be controlled. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide a device for controlling and discharging accumulated liquid in the annulus of a marine flexible pipe, which solves the problem that the discharge of accumulated liquid in the annulus of the marine flexible pipe cannot be controlled at present.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: In a first aspect, the present application discloses a liquid collecting device, comprising a liquid suction tank, a partition plate is arranged in the liquid suction tank, the partition plate divides the inside of the liquid suction tank into a hydraulic oil part located at the upper part and an accumulated liquid part located at the lower part, a limit switch is arranged in the accumulated liquid part of the liquid suction tank, and a liquid inlet and a liquid outlet are arranged at both ends of the accumulated liquid part of the liquid suction tank, respectively; A hydraulic oil tank is stacked on the liquid suction tank, and a steering switch is arranged between the hydraulic oil tank and the liquid suction tank, and the hydraulic oil tank and the hydraulic oil part of the liquid suction tank are connected through a hydraulic oil pipe; A bidirectional pump is arranged on the hydraulic oil pipe; When the bidirectional pump is forward rotating, the bidirectional pump delivers the hydraulic oil in the hydraulic oil part of the liquid suction tank into the hydraulic oil tank, the hydraulic oil in the hydraulic oil part of the liquid suction tank is reduced, and the separation plate is driven to move upward, causing the negative pressure of the percolation liquid part, so that the percolation liquid is sucked into the liquid inlet of the percolation liquid part; at the same time, the hydraulic oil in the hydraulic oil tank is increased, and the hydraulic oil tank is close to the steering switch under the action of gravity until the steering switch is touched; When the bidirectional pump is reverse rotating, the bidirectional pump delivers the hydraulic oil in the hydraulic oil tank into the hydraulic oil part of the liquid suction tank, the hydraulic oil in the hydraulic oil part of the liquid suction tank is increased, and the separation plate is driven to move downward, thereby compressing the percolation liquid part of the liquid suction tank, driving the percolation liquid in the percolation liquid part of the liquid suction tank to flow out from the liquid outlet, causing the separation plate to move downward until the separation plate touches the limit switch.

[0007] Further, a liquid storage tank is arranged, and the liquid inlet of the liquid storage tank is connected with the liquid outlet of the percolation liquid part of the liquid suction tank through a percolation liquid discharge pipeline; When the bidirectional pump is reverse rotating, the separation plate is driven to move downward and compress the percolation liquid part of the liquid suction tank, and after the percolation liquid in the percolation liquid part of the liquid suction tank flows out from the liquid outlet, the percolation liquid flows into the liquid storage tank through the percolation liquid discharge pipeline.

[0008] Preferably, a liquid level indicator is arranged at the top of the liquid storage tank, and the liquid level indicator faces downward to the liquid surface in the liquid storage tank, and is used to monitor the height value of the liquid surface in the liquid storage tank.

[0009] Further, a controller is arranged, and the bidirectional pump, the limit switch, the steering switch and the liquid level indicator are connected with the controller respectively.

[0010] 5. The liquid collecting device according to claim 2, further comprising a pry anti-sinking base, The liquid suction tank and the liquid storage tank are arranged at two ends of the pry anti-sinking base respectively; The bidirectional pump is fixed on the pry anti-sinking base and located between the liquid suction tank and the liquid storage tank.

[0011] Preferably, the liquid inlet of the liquid suction tank is provided with a front connecting pipe, one end of the front connecting pipe is connected with the liquid inlet of the liquid suction tank, and the other end is provided with a female head of a first quick connector; a first check valve is arranged on the front connecting pipe.

[0012] Preferably, the liquid outlet of the liquid suction tank is provided with a rear docking pipe, one end of the rear docking pipe is docked with the liquid outlet of the liquid suction tank, and the other end is provided with a second quick connector, and the pipeline extending from the inlet of the liquid storage tank is connected together with the rear docking pipe through the second quick connector.

[0013] Further, the hydraulic oil tank is provided with a sealing plate.

[0014] Further, a plurality of compression springs are arranged around the steering switch at intervals, and two ends of each compression spring are fixed on the hydraulic oil tank and the liquid suction tank, respectively.

[0015] In the second aspect, the application further discloses a device for controlling and discharging accumulated liquid in the annulus of a marine flexible pipe, which is arranged on a marine flexible pipe connecting a manifold and a marine drilling and production platform, and comprises the liquid collecting device and an annulus connecting pipe, wherein the liquid inlet end of the annulus connecting pipe is arranged on the marine flexible pipe and is in communication with the annulus of the marine flexible pipe. The male head of the first quick connector arranged at the end of the annulus connecting pipe is matched with the female head of the first quick connector arranged on the front docking pipe of the liquid suction tank of the liquid collecting device to form a set of quick connectors, and the front docking pipe of the liquid inlet of the liquid suction tank of the liquid collecting device is docked with the liquid outlet end of the annulus connecting pipe through the first quick connector.

[0016] Further, the annulus connecting pipe is provided with a communication valve and a third check valve.

[0017] In the third aspect, the application further discloses a method for controlling and discharging accumulated liquid in the annulus of a marine flexible pipe, a annulus connecting pipe is arranged on a marine flexible pipe connecting a manifold and a marine drilling and production platform in advance, the liquid inlet end of the annulus connecting pipe is arranged on the marine flexible pipe and is in communication with the annulus of the marine flexible pipe, and the above-mentioned device for controlling and discharging accumulated liquid in the annulus of a marine flexible pipe is used, and the method comprises the following steps. Step A: the liquid collecting device is lowered to the seabed near the marine flexible pipe through a rigging, and is close to the first quick connector of the annulus connecting pipe, a subsea robot is lowered from the marine drilling and production platform, the front docking pipe of the liquid inlet of the liquid suction tank of the liquid collecting device is docked with the liquid outlet end of the annulus connecting pipe through the first quick connector by the subsea robot, and the subsea robot supplies power to the bidirectional pump through a cable to make the bidirectional pump rotate forward. Step B: when the bidirectional pump is rotating forward, the bidirectional pump transports the hydraulic oil in the hydraulic oil part of the suction tank into the hydraulic oil tank, the hydraulic oil in the hydraulic oil part of the suction tank is reduced, and the partition plate is driven to move upward, causing the negative pressure of the percolation liquid part, and the percolation liquid in the annulus of the marine flexible pipe is sucked into the suction tank; at the same time, the hydraulic oil in the hydraulic oil tank is increased, and the hydraulic oil tank is close to the steering switch under the action of gravity until the steering switch is touched; Step C: the steering switch transmits the information that the hydraulic oil tank touches the steering switch to the controller, and the controller controls the bidirectional pump to rotate reversely; Step D: when the bidirectional pump is rotating reversely, the bidirectional pump reversely transports the hydraulic oil in the hydraulic oil tank into the hydraulic oil part of the suction tank, the hydraulic oil in the hydraulic oil part of the suction tank is increased, and the partition plate is driven to move downward, thereby compressing the percolation liquid part of the suction tank, causing the percolation liquid in the percolation liquid part of the suction tank to flow out of the liquid outlet, and causing the partition plate to move downward until the partition plate touches the partition plate; Step E: the limit switch transmits the information that the partition plate touches the partition plate to the controller, and the controller controls the bidirectional pump to rotate forward; Step F: steps B to E are repeated until the liquid level indicator provided at the top of the liquid storage tank detects that the height value of the liquid level in the liquid storage tank no longer changes, and the liquid level indicator transmits the information that the height value of the liquid level in the liquid storage tank no longer changes to the controller, and the controller controls the bidirectional pump to stop rotating.

[0018] Compared with the prior art, the beneficial effects of the present application are: (I) The application discloses a liquid collecting device, characterized in that the device comprises a liquid suction tank, a hydraulic oil tank and a bidirectional pump, a partition plate is arranged in the liquid suction tank, the partition plate divides the inside of the liquid suction tank into a hydraulic oil part located at the upper portion and a seepage liquid part located at the lower portion, a limit switch is arranged in the seepage liquid part of the liquid suction tank, and a liquid inlet and a liquid outlet are arranged at the two ends of the seepage liquid part of the liquid suction tank respectively; the hydraulic oil tank is stacked on the liquid suction tank, a steering switch is arranged between the hydraulic oil tank and the liquid suction tank, the hydraulic oil tank and the hydraulic oil part of the liquid suction tank are connected through a hydraulic oil pipe, and the bidirectional pump is arranged in the hydraulic oil pipe. When the bidirectional pump rotates forward, the bidirectional pump transports the hydraulic oil in the hydraulic oil part of the liquid suction tank into the hydraulic oil tank, the hydraulic oil in the hydraulic oil part of the liquid suction tank is reduced, the partition plate is moved upward, a negative pressure is formed in the seepage liquid part, and the liquid inlet of the seepage liquid part is facilitated to suck in seepage liquid. At the same time, the hydraulic oil in the hydraulic oil tank is increased, and the hydraulic oil tank is close to the steering switch under the action of gravity until the steering switch is touched. When the bidirectional pump rotates reversely, the bidirectional pump reversely transports the hydraulic oil in the hydraulic oil tank into the hydraulic oil part of the liquid suction tank, the hydraulic oil in the hydraulic oil part of the liquid suction tank is increased, the partition plate is lowered, the seepage liquid part of the liquid suction tank is compressed, the seepage liquid in the seepage liquid part of the liquid suction tank flows out from the liquid outlet, the partition plate is lowered until the partition plate touches the limit switch. When the partition plate touches the limit switch, the bidirectional pump rotates forward again, the above steps are repeated until the liquid level in the liquid storage tank is constant. Thus, the purpose of discharging seepage liquid in the annular space of the marine flexible riser is achieved. The liquid collecting device disclosed by the application realizes the control of boundary conditions through the forward rotation and reverse rotation of the bidirectional pump and the cooperation of the steering switch and the limit switch, and thus the discharge of liquid is controlled.

[0019] (II) The application discloses a seepage liquid discharging control device in the annular space of a marine flexible pipeline, and the liquid collecting device is applied to the annular space of the marine flexible pipeline to quickly suck out seepage liquid in the marine flexible pipeline, and thus the discharge of seepage liquid in the annular space of the marine flexible pipeline is controlled.

[0020] (III) The application discloses a seepage liquid discharging control method in the annular space of a marine flexible pipeline, and the seepage liquid discharging control device in the annular space of the marine flexible pipeline is adopted, and the method comprises the following steps. Step A: the liquid collecting device is lowered to the seabed near the marine flexible pipeline through a rigging, and is close to the first quick connector of the annular space connecting pipe, a subsea robot is lowered from a marine drilling and production platform, the front butt joint pipe on the liquid inlet of the liquid suction tank of the liquid collecting device is butt jointed with the liquid outlet end of the annular space connecting pipe through the first quick connector, and the subsea robot supplies power to the bidirectional pump through a cable to make the bidirectional pump rotate forward. Step B: When the bidirectional pump rotates in the forward direction, it delivers hydraulic oil from the hydraulic oil section of the suction tank to the hydraulic oil tank. The hydraulic oil in the hydraulic oil section of the suction tank decreases accordingly, causing the partition plate to move upward, creating a negative pressure in the seepage area. This negative pressure draws the seepage fluid in the annulus of the marine flexible pipeline into the suction tank. At the same time, the hydraulic oil in the hydraulic oil tank increases accordingly, and the hydraulic oil tank, under its own weight, moves closer to the turn switch until it touches the turn switch. Step C: The steering switch will transmit the information that the hydraulic oil tank has touched the steering switch to the controller, and the controller will control the bidirectional pump to rotate in the opposite direction; Step D: When the bidirectional pump reverses, it pumps the hydraulic oil in the hydraulic tank to the hydraulic oil section of the suction tank. The hydraulic oil in the suction tank increases, pushing the partition plate down and compressing the seepage section of the suction tank. This causes the seepage liquid in the seepage section of the suction tank to flow out from the outlet, resulting in the partition plate descending until it touches the partition plate. Step E: The limit switch transmits the information that the partition plate has touched the partition plate to the controller, and the controller controls the bidirectional pump to rotate in the forward direction; Step F: Repeat steps B to E until the liquid level indicator at the top of the storage tank detects that the liquid level in the storage tank no longer changes. The liquid level indicator transmits the information that the liquid level in the storage tank no longer changes to the controller, and the controller controls the bidirectional pump to stop rotating.

[0021] In summary, the liquid collection device disclosed in this invention has a high degree of automation. The marine flexible pipeline annular seepage control and drainage device disclosed in this invention is easy to operate and safe and reliable. The marine flexible pipeline annular seepage control and drainage method disclosed in this invention has the advantages of convenience, flexibility, safety and reliability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the liquid collection device provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the control device provided in Embodiment 1 of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the marine flexible pipeline annulus seepage control and drainage device provided in Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the structure of the marine flexible pipeline annulus seepage control and drainage device of Embodiment 2 of the present invention applied to the pipeline connecting the manifold and the marine drilling and production platform. Figure 5 forFigure 4 a local enlarged view of A in FIG. 1; a schematic diagram of a flexible riser top structure provided by the embodiment 1 of the present application; Figure 6 To Figure 4 a local enlarged view of B in FIG. 1.

[0024] Legend: 100-liquid collecting device; 10-separation plate, 11-liquid suction tank, 12-hydraulic oil tank, 120-sealing plate, 13-bidirectional pump; 2-controller, 21-limit switch, 22-turning switch, 220-compression spring, 23-liquid level indicator; 3-liquid storage tank; 4-scraper-mounted anti-settlement base; 51-front butt joint pipe, 511-first quick connector, 512-first check valve; 52-rear butt joint pipe, 521-second quick connector, 522-second check valve; 6-annular space connecting pipe, 61-communication valve, 62-third check valve. DETAILED DESCRIPTION

[0025] Exemplary embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms without being limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0026] Example 1: A liquid collecting device The present application provides a liquid collecting device, and the structure thereof will be described in detail below with reference to the accompanying drawings.

[0027] Referring to Figure 1 , the liquid collecting device comprises: a liquid suction tank 11, a separation plate 10 is arranged in the liquid suction tank 11, the separation plate 10 divides the inside of the liquid suction tank 11 into a hydraulic oil part at the upper part and a seepage liquid part at the lower part, a limit switch 21 is arranged in the seepage liquid part of the liquid suction tank 11, and a liquid inlet and a liquid outlet are arranged at both ends of the seepage liquid part of the liquid suction tank 11; a hydraulic oil tank 12, the hydraulic oil tank 12 is stacked on the liquid suction tank 11, a turning switch 22 is arranged between the hydraulic oil tank 12 and the liquid suction tank 11, and the hydraulic oil tank 12 and the hydraulic oil part of the liquid suction tank 11 are connected through a hydraulic oil pipe; a bidirectional pump 13 arranged on the hydraulic oil pipe; When the bidirectional pump 13 rotates forward, the bidirectional pump 13 transports the hydraulic oil in the hydraulic oil part of the liquid suction tank 11 into the hydraulic oil tank 12, the hydraulic oil in the hydraulic oil part of the liquid suction tank 11 decreases, and the partition plate 10 moves upward, causing the seepage liquid part to form a negative pressure, so as to facilitate the seepage liquid inlet of the seepage liquid part to suck in the seepage liquid; at the same time, the hydraulic oil in the hydraulic oil tank 12 increases, and the hydraulic oil tank 12 approaches the steering switch 22 under the action of gravity until the hydraulic oil tank 12 touches the steering switch 22; When the bidirectional pump 13 rotates reversely, the bidirectional pump 13 reversely transports the hydraulic oil in the hydraulic oil tank 12 into the hydraulic oil part of the liquid suction tank 11, the hydraulic oil in the hydraulic oil part of the liquid suction tank 11 increases, and the partition plate 10 is pushed to descend, thereby compressing the seepage liquid part of the liquid suction tank 11, promoting the seepage liquid in the seepage liquid part of the liquid suction tank 11 to flow out from the liquid outlet, causing the partition plate 10 to descend until the partition plate 10 touches the limit switch 21.

[0028] In order to store the seepage liquid flowing out from the liquid outlet of the seepage liquid part of the liquid suction tank 11, the liquid collecting device further comprises a liquid storage tank 3, and the inlet of the liquid storage tank 3 is connected in communication with the liquid outlet of the seepage liquid part of the liquid suction tank 11 through a seepage liquid discharge pipeline.

[0029] When the bidirectional pump 13 rotates reversely, the partition plate 10 descends and compresses the seepage liquid part of the liquid suction tank 11, promoting the seepage liquid in the seepage liquid part of the liquid suction tank 11 to flow out from the liquid outlet and then flow to the liquid storage tank 3 through the seepage liquid discharge pipeline for storage.

[0030] In order to determine the boundary condition of the stop of the bidirectional pump 13, a liquid level indicator 23 is arranged at the top of the liquid storage tank 3, the liquid level indicator 23 downwardly faces the liquid level in the liquid storage tank 3, and is used for monitoring the height value of the liquid level in the liquid storage tank 3.

[0031] In order to facilitate control, the liquid collecting device further comprises a control device, the control device comprises a controller 2, and the bidirectional pump 13, the limit switch 21, the steering switch 22 and the liquid level indicator 23 are connected with the controller 2.

[0032] In order to solve the problem of the liquid collecting device from the sea surface to the seabed, it is most convenient to integrate the above functional components on an overall base, that is, a pry-mounted integrated mode. Therefore, the liquid collecting device further comprises a pry-mounted anti-sinking base 4.

[0033] The liquid suction tank 11 and the liquid storage tank 3 are respectively arranged at two ends of the pry anti-settlement base 4; the bidirectional pump 13 is fixed on the pry anti-settlement base 4 and located between the liquid suction tank 11 and the liquid storage tank 3.

[0034] In order to facilitate the liquid suction tank 11 to receive liquid through the liquid inlet, a specific embodiment is that the liquid inlet of the liquid suction tank 11 is provided with a front docking pipe 51, one end of the front docking pipe 51 is docked with the liquid inlet of the liquid suction tank 11, and the other end is provided with a female head of a first quick connector 511.

[0035] In order to ensure that the liquid flows into the liquid suction tank 11 through the front docking pipe 51, a first check valve 512 is arranged on the front docking pipe 51.

[0036] In order to dock the liquid outlet of the liquid suction tank 11 with the inlet of the liquid storage tank 3, the liquid outlet of the liquid suction tank 11 is provided with a rear docking pipe 52, one end of the rear docking pipe 52 is docked with the liquid outlet of the liquid suction tank 11, and the other end is provided with a second quick connector 521, and a pipeline extending from the inlet of the liquid storage tank 3 is connected together with the rear docking pipe 52 through the second quick connector 521.

[0037] In order to ensure that the percolation liquid flowing out of the rear docking pipe 52 flows smoothly into the inlet of the liquid storage tank 3, a second check valve 522 is arranged on the rear docking pipe 52.

[0038] In order to prevent the hydraulic oil from flowing out of the hydraulic oil tank 12 and provide a sealed environment, the hydraulic oil tank 12 is provided with a sealing plate 120.

[0039] In order to ensure that the hydraulic oil tank 12 will be close to the steering switch 22 under the action of gravity, a plurality of compression springs 220 are arranged around the steering switch 22, and two ends of each compression spring 220 are fixed on the hydraulic oil tank 12 and the liquid suction tank 11 respectively.

[0040] In order to facilitate hoisting, a lifting point is arranged on the top of the liquid storage tank 3.

[0041] Since the quick connector has a male head and a female head, and the male head and the female head are connected by plugging, it is a conventional technical means in the art, specifically, the first quick connector 511 and the second check valve 522 in the embodiment of the application all adopt the quick connector with the male head and the female head plugged together, which will not be described here.

[0042] Embodiment 2: A percolation liquid control and discharge device in an annulus of a marine flexible pipeline The embodiment 2 of the application provides a percolation liquid control and discharge device in an annulus of a marine flexible pipeline, which is arranged on a marine flexible pipeline connecting a pipe manifold and a marine drilling and production platform, and the structure thereof will be described in detail below with reference to the drawings.

[0043] Reference Figures 3 to 6 The annulus liquid seepage control and discharge device of the marine flexible pipe, comprising the liquid collecting device of embodiment 1 and an annulus connecting pipe 6, the marine flexible pipe is connected with the liquid collecting device through the annulus connecting pipe 6.

[0044] Specifically, the liquid inlet end of the annulus connecting pipe 6 is arranged on the marine flexible pipe and communicates with the annulus of the marine flexible pipe; the male end of the first quick connector 511 arranged at the end of the annulus connecting pipe 6 is matched with the female end of the first quick connector 511 arranged on the front connecting pipe 51 to form a set of quick connectors; the front connecting pipe 51 on the liquid inlet of the liquid suction tank 11 of the liquid collecting device is connected with the liquid outlet end of the annulus connecting pipe 1 through the first quick connector 511.

[0045] In order to facilitate the control of the disconnection and connection of the annulus connecting pipe 6, a communication valve 61 is arranged on the annulus connecting pipe 6, as shown in Figure 6 .

[0046] In order to ensure that the liquid flows into the liquid suction tank 11 through the communication valve 61, a third check valve 62 is arranged on the annulus connecting pipe 6, as shown in Figure 6 , the reason is the same as the above-mentioned check valve, and will not be repeated here.

[0047] Reference Figure 5 The annular space is formed between the inner liner and the outer protective layer of the marine flexible pipe, in order to continuously output the seepage liquid in the annular space, as a common knowledge, the annular space is communicated with the atmosphere to maintain constant. In order to facilitate the continuous output of the seepage liquid from the annular space, a flange is arranged on the marine flexible pipe connected with the offshore drilling platform, the marine flexible pipe is fixed on the flange, and an air pipe is arranged on the annular space, the air pipe is inserted into the annular space, and the annular space is communicated through the air pipe.

[0048] Preferably, a communication valve is arranged on the air pipe, as shown in Figure 5 .

[0049] In order to facilitate the installation of the liquid collecting device, as a common knowledge, the annulus connecting pipe 6 needs to be arranged on the marine flexible pipe connected with the marine drilling platform and the connecting pipe manifold in advance, the liquid inlet end of the annulus connecting pipe 6 is arranged on the marine flexible pipe and communicates with the annulus of the marine flexible pipe, and the technical means is a conventional technical operation of marine engineering, which will not be repeated here.

[0050] Embodiment 3: A method for controlling and discharging the seepage liquid in the annulus of the marine flexible pipe Embodiment 3 of the present application provides a method for controlling and discharging accumulated fluid in the annulus of a marine flexible pipe, a connecting pipe 6 is arranged in advance on the marine flexible pipe connecting a manifold and a marine drilling and production platform, the liquid inlet end of the connecting pipe 6 is arranged on the marine flexible pipe and is in communication with the annulus of the marine flexible pipe, and the marine flexible pipe annulus accumulated fluid control and discharge device provided in embodiment 2 is used, the method comprises the following steps: Step A: the liquid collecting device is lowered to the seabed near the marine flexible pipe by a rigging, and is close to the first quick connector 511 of the annulus connecting pipe 6, a remotely operated vehicle (ROV) is lowered from the marine drilling and production platform, the ROV realizes the butt joint of the front butt joint pipe 51 on the liquid inlet of the liquid collecting device and the liquid outlet end of the annulus connecting pipe 1 through the first quick connector 511, and the ROV (ROV) supplies power to the bidirectional pump 13 through a cable to make the bidirectional pump 13 rotate forward; Step B: when the bidirectional pump 13 rotates forward, the bidirectional pump 13 transports the hydraulic oil of the hydraulic oil part of the liquid collecting tank 11 into the hydraulic oil tank 12, the hydraulic oil in the hydraulic oil part of the liquid collecting tank 11 decreases, and the separation plate 10 moves upward, causing the formation of negative pressure in the accumulated fluid part, and the negative pressure causes the accumulated fluid in the annulus of the marine flexible pipe to be sucked into the liquid collecting tank; at the same time, the hydraulic oil in the hydraulic oil tank 12 increases, and the hydraulic oil tank 12 approaches the turning switch 22 under the action of gravity until the turning switch 22 is touched; Step C: the turning switch 22 transmits the information that the hydraulic oil tank 12 touches the turning switch 22 to the controller 2, and the controller 2 controls the bidirectional pump 13 to rotate reversely; Step D: when the bidirectional pump 13 reverses, the bidirectional pump 13 reversely transports the hydraulic oil in the hydraulic oil tank 12 into the hydraulic oil part of the liquid collecting tank 11, the hydraulic oil in the hydraulic oil part of the liquid collecting tank 11 increases, and the separation plate 10 is pushed downward, thereby compressing the accumulated fluid part of the liquid collecting tank 11, and causing the accumulated fluid in the accumulated fluid part of the liquid collecting tank 11 to flow out of the liquid outlet, resulting in the downward movement of the separation plate 10 until the separation plate 10 touches the separation plate 10; Step E: the limit switch 21 transmits the information that the separation plate 10 touches the separation plate 10 to the controller 2, and the controller 2 controls the bidirectional pump 13 to rotate forward; Step F: steps B to E are repeated until the liquid level indicator 23 arranged at the top of the liquid storage tank 3 monitors that the height value of the liquid level in the liquid storage tank 3 no longer changes, and the liquid level indicator 23 transmits the information that the height value of the liquid level in the liquid storage tank 3 no longer changes to the controller 2, and the controller 2 controls the bidirectional pump 13 to stop rotating.

[0051] After the work is completed, the operator disconnects the power cable and the first quick joint 511 of the bidirectional pump 13, connects the rope to the lifting point, and lifts the liquid storage tank 3 to the offshore drilling platform, i.e. the work of discharging the accumulated liquid in the annulus of the offshore flexible pipe is completed.

[0052] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit it. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A liquid collection device, characterized in that, include A liquid suction box (11) is provided with a partition plate (10) inside. The partition plate (10) divides the interior of the liquid suction box (11) into a hydraulic oil section located at the top and a liquid seepage section located at the bottom. A limit switch (21) is provided inside the liquid seepage section of the liquid suction box (11). An inlet and an outlet are respectively provided at both ends of the liquid seepage section of the liquid suction box (11). A hydraulic oil tank (12) is stacked on the suction tank (11), and a directional switch (22) is provided between the hydraulic oil tank (12) and the suction tank (11). The hydraulic oil parts of the hydraulic oil tank (12) and the suction tank (11) are connected by hydraulic oil pipes. A two-way pump (13) is installed on the hydraulic oil pipe; When the bidirectional pump (13) rotates in the forward direction, the bidirectional pump (13) delivers the hydraulic oil from the hydraulic oil section of the suction tank (11) to the hydraulic oil tank (12). The hydraulic oil in the hydraulic oil section of the suction tank (11) will decrease accordingly, and the partition plate (10) will move upward, creating a negative pressure in the seepage section, so as to facilitate the intake of seepage liquid at the inlet of the seepage section. At the same time, the hydraulic oil in the hydraulic oil tank (12) will increase accordingly, and the hydraulic oil tank (12) will approach the turn switch (22) under its own weight until it touches the turn switch (22). When the bidirectional pump (13) rotates in reverse, the bidirectional pump (13) reverses the flow of hydraulic oil from the hydraulic oil tank (12) to the hydraulic oil section of the suction tank (11). The hydraulic oil in the hydraulic oil section of the suction tank (11) increases and pushes the partition plate (10) down, thereby compressing the seepage section of the suction tank (11) and causing the seepage in the seepage section of the suction tank (11) to flow out from the outlet, causing the partition plate (10) to descend until the partition plate (10) descends and touches the limit switch (21).

2. The liquid collection device according to claim 1, characterized in that, It also includes a liquid storage tank (3). The inlet of the storage tank (3) is connected to the outlet of the liquid accumulation section of the liquid suction box (11) through a liquid accumulation discharge pipe. When the bidirectional pump (13) rotates in reverse, the partition plate (10) descends and compresses the liquid accumulation section of the suction box (11), causing the liquid accumulation in the liquid accumulation section of the suction box (11) to flow out from the outlet and then flow through the liquid accumulation discharge pipe into the storage tank (3) for storage.

3. The liquid collection device according to claim 2, characterized in that, A liquid level indicator (23) is provided at the top of the liquid storage tank (3). The liquid level indicator (23) faces downwards and is directly opposite the liquid level in the liquid storage tank (3) to monitor the height value reached by the liquid level in the liquid storage tank (3).

4. The liquid collection device according to claim 3, characterized in that, It also includes a controller (2). The bidirectional pump (13), the limit switch (21), the directional switch (22) and the liquid level indicator (23) are respectively connected to the controller (2).

5. The liquid collection device according to claim 2, characterized in that, It also includes skid-mounted anti-sinking base (4). The liquid suction box (11) and the liquid storage tank (3) are respectively located at both ends of the skid-mounted anti-sinking base (4); The bidirectional pump (13) is fixed on the skid-mounted anti-sinking base (4) and is located between the suction tank (11) and the storage tank (3).

6. The liquid collection device according to claim 1, characterized in that, The liquid inlet of the liquid suction box (11) is equipped with a front connecting pipe (51), one end of the front connecting pipe (51) is connected to the liquid inlet of the liquid suction box (11), and the other end is provided with a female head of a first quick connector (511). A first check valve (512) is provided on the front connecting pipe (51).

7. The liquid collection device according to claim 2, characterized in that, The outlet of the liquid suction box (11) is equipped with a rear connecting pipe (52). One end of the rear connecting pipe (52) is connected to the outlet of the liquid suction box (11), and the other end is provided with a second quick connector (521). The pipe extending from the inlet of the liquid storage tank (3) is connected to the rear connecting pipe (52) through the second quick connector (521). A second check valve (522) is provided on the rear connecting pipe (52).

8. The liquid collection device according to claim 1, characterized in that, The hydraulic oil tank (12) is equipped with a sealing plate (120); Several compression springs (220) are arranged at intervals around the turn switch (22), and the two ends of each compression spring (220) are fixed on the hydraulic oil tank (12) and the liquid suction tank (11) respectively.

9. A device for controlling and draining seepage fluid in the annulus of a marine flexible pipeline, used for installation on a marine flexible pipeline connecting a manifold and a marine drilling platform, characterized in that, It includes the liquid collection device as described in claim 6 and an annular connecting pipe (6). The inlet end of the annular connecting pipe (6) is set on the marine flexible pipe and connected to the annulus of the marine flexible pipe. The end of the annular connecting pipe (6) is provided with a male head of a first quick connector (511). The male head of the first quick connector (511) at the end of the annular connecting pipe (6) is paired with the female head of the first quick connector (511) on the front connecting pipe (51) to form a set of quick connectors. The front connecting pipe (51) on the liquid inlet of the liquid collection device's suction box (11) is connected to the liquid outlet of the annular connecting pipe (1) through the first quick connector (511). The annular connecting pipe (6) is equipped with a connecting valve (61) and a third check valve (62).

10. A method for controlling and draining seepage fluid in the annulus of a marine flexible pipeline, wherein an annulus connecting pipe (6) is pre-installed on the marine flexible pipeline connecting the manifold and the marine drilling platform, the inlet end of the annulus connecting pipe (6) is located on the marine flexible pipeline and is connected to the annulus of the marine flexible pipeline, and the method employs the marine flexible pipeline annulus seepage fluid control and drainage device as described in claim 9, characterized in that, include Step A: The liquid collection device is lowered to the seabed near the marine flexible pipeline using rigging, and close to the first quick connector (511) of the annular connecting pipe (6). The marine drilling platform lowers an underwater robot, and the underwater robot connects the front connecting pipe (51) on the liquid inlet of the liquid collection device's suction box (11) with the liquid outlet of the annular connecting pipe (1) through the first quick connector (511). The underwater robot supplies power to the bidirectional pump (13) through a cable, causing the bidirectional pump (13) to rotate in the forward direction. Step B: When the bidirectional pump (13) rotates in the forward direction, the bidirectional pump (13) delivers the hydraulic oil from the hydraulic oil section of the suction tank (11) to the hydraulic oil tank (12). The hydraulic oil in the hydraulic oil section of the suction tank (11) will decrease accordingly, and cause the partition plate (10) to move upward, resulting in a negative pressure in the seepage section. The negative pressure causes the seepage liquid in the annulus of the marine flexible pipeline to be sucked into the suction tank. At the same time, the hydraulic oil in the hydraulic oil tank (12) will increase accordingly. Under its own weight, the hydraulic oil tank (12) will approach the turn switch (22) until it touches the turn switch (22). Step C: The steering switch (22) transmits the information that the hydraulic tank (12) touches the steering switch (22) to the controller (2), and the controller (2) controls the bidirectional pump (13) to rotate in the opposite direction; Step D: When the bidirectional pump (13) rotates in reverse, the bidirectional pump (13) reverses the flow of hydraulic oil in the hydraulic oil tank (12) to the hydraulic oil section of the suction tank (11). The hydraulic oil in the hydraulic oil section of the suction tank (11) will increase, and push the partition plate (10) to drop, thereby compressing the seepage section of the suction tank (11), causing the seepage in the seepage section of the suction tank (11) to flow out from the outlet, causing the partition plate (10) to drop until the partition plate (10) drops and touches the partition plate (10). Step E: The limit switch (21) transmits the information that the partition plate (10) has touched the partition plate (10) to the controller (2), and the controller (2) controls the bidirectional pump (13) to rotate in the forward direction; Step F: Repeat steps B to E until the liquid level indicator (23) installed at the top of the storage tank (3) detects that the height of the liquid level in the storage tank (3) no longer changes. The liquid level indicator (23) transmits the information that the height of the liquid level in the storage tank (3) no longer changes to the controller (2). The controller (2) controls the bidirectional pump (13) to stop rotating.

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