Anti-scour cement grouting device for governing suspended span of submarine pipeline

Abstract

The invention relates to the technical field of offshore oil engineering, in particular to an anti-scour cement grouting device for governing suspended span of submarine pipelines, which is used for solving the problem that an existing device cannot have the functions of fixing and stabilizing and secondary suspended span governing at the same time. The first grouting bag is fixed to the seabed and located on the lower portion of the suspended span position of the pipeline, and a fixing mechanism is fixedly arranged on the upper portion of the first grouting bag. When grouting is conducted in the first grouting bag, the size of the first grouting bag is increased so that the gap between the pipeline and the seabed can be filled, and after the pipeline is supported by the first grouting bag, the pipeline is fixed to the fixing mechanism so that the pipeline can be fixed to the first grouting bag; the device makes full use of the characteristics of high structural supporting strength, adjustable suspended span treatment height, prevention of secondary suspended span of the pipeline, stabilization and fixation of the pipeline, simple operation, high pertinence and the like of an anti-scouring grouting device, the suspended span problem in the production process of the submarine pipeline is well solved, and safe operation of the submarine pipeline in the service period is realized.

Description

Technical Field

[0001] This invention relates to the field of marine oil engineering technology, and in particular to an anti-scouring cement grouting device for treating the suspension of subsea pipelines. Background Technology

[0002] Currently, offshore oil development mainly adopts the platform construction method. The extracted crude oil is processed at the ground terminal, and the crude oil is mainly transported by barges and subsea pipelines. Due to the advantages of high oil transportation efficiency, fast commissioning speed, convenient management and low operating costs, subsea pipelines have become the main mode of transportation for offshore oil and gas.

[0003] However, while subsea pipelines have many advantages in transporting oil and gas, they also pose varying degrees of safety hazards. Subsea pipelines are laid on the seabed or buried in the seabed soil. Due to the unevenness of the seabed and the scouring effect of waves and currents, pipelines inevitably experience overhangs. Such undesigned overhangs are detrimental to the safe operation of subsea pipelines. Overhangs can easily lead to pipeline damage and leakage, causing serious economic losses and adverse social impacts.

[0004] Extensive research has been conducted both domestically and internationally on methods for preventing and maintaining subsea pipeline sags, primarily including parabolic grouting, seabed topography clearing, mechanical support, and flexible pipe methods. Parabolic grouting is one of the simplest and most effective methods, with anti-erosion cement grout bags being a commonly used grouting tool. The main principle involves setting up a supporting membrane on the seabed, which is then filled with cement grout to support the pipeline, providing upward support to the sag. A search revealed that patent CN217762349U can address pipeline sags, but it cannot solve the problem of secondary sags; patent CN106400806A can effectively address secondary sags, but it cannot solve the stability of the pipeline above the grouting zone, nor can it guarantee the overall stability of the grout bag device; patent CN208844575U can fix the pipeline, but it cannot prevent secondary sags. Therefore, existing devices still require improvement. Summary of the Invention

[0005] This invention provides an anti-scouring cement grouting device for treating the suspension of submarine pipelines, in order to solve the problem that existing devices cannot simultaneously provide both fixed stability and secondary suspension treatment.

[0006] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] A cement grouting device for preventing erosion of a suspended subsea pipeline includes a first grouting bag, which is fixed to the seabed and located below the suspended position of the pipeline, and a fixing mechanism is fixedly installed on the upper part of the first grouting bag.

[0008] When grout is injected into the first grouting bag, the volume of the first grouting bag increases, thereby filling the gap between the pipe and the seabed. After the pipe is supported by the first grouting bag, the pipe is fixed to the fixing mechanism, thereby fixing the pipe to the first grouting bag.

[0009] Furthermore, the fixing mechanism includes a first clamping block and a second clamping block. Arc-shaped grooves are provided on the opposite surfaces of the first clamping block and the second clamping block. Connecting rods are connected to both the first clamping block and the second clamping block, and connecting plates are connected to both sets of connecting rods.

[0010] The connecting rod is threaded to the corresponding first clamp and second clamp. The connecting plate has a through groove that mates with the connecting rod. When the connecting rod is screwed onto the corresponding first clamp and second clamp, the connecting rod can press the connecting plate onto the first clamp and second clamp, thereby the first clamp and second clamp can fix and clamp the pipe.

[0011] Furthermore, it also includes a base, to which the first grouting bag is fixedly connected. Each of the four corners of the base has a circular hole, into which a connecting cylinder is inserted. The connecting cylinder passes through the circular hole and is inserted into the seabed.

[0012] Furthermore, the top end of the connecting cylinder is provided with a thread, and a locking nut is connected to the thread, with a washer placed at the bottom of the locking nut;

[0013] Tightening the locking nut secures the base to the connecting cylinder.

[0014] Furthermore, the base is covered with an artificial grass mat, which is woven from strips of artificial grass made of erosion-resistant material.

[0015] Furthermore, a second grouting bag is connected to the upper part of the first grouting bag.

[0016] Furthermore, a spare grouting bag is connected to the upper part of the second grouting bag.

[0017] Furthermore, the first grouting bag, the second grouting bag, and the spare grouting bag are all connected to grouting pipes and backflow pipes. Cement slurry is injected through the grouting pipes, and after the corresponding grouting bag is filled with cement slurry, the cement slurry is discharged through the backflow pipes.

[0018] Furthermore, a first check valve is provided on the grouting pipe, and a second check valve is provided on the backflow pipe. The opening pressure of the second check valve is greater than or equal to 0.05 MPa and less than or equal to 0.15 MPa.

[0019] Furthermore, the first grouting bag, the second grouting bag, and the spare grouting bag are all connected to a steel reinforcement cage, and the steel reinforcement cage is internally connected to multiple reinforcing ribs arranged horizontally and vertically.

[0020] The beneficial effects of this invention are analyzed as follows:

[0021] A cement grouting device for preventing erosion of a suspended subsea pipeline includes a first grouting bag, which is fixed to the seabed and located below the suspended position of the pipeline. A fixing mechanism is fixedly installed on the upper part of the first grouting bag. When grout is injected into the first grouting bag, the volume of the first grouting bag increases, thereby filling the gap between the pipeline and the seabed. After the pipeline is supported by the first grouting bag, the pipeline is fixed to the fixing mechanism, thereby fixing the pipeline to the first grouting bag.

[0022] After determining the location of the suspended subsea pipeline through engineering practice, a scour-resistant grouting support scheme was developed. Based on the construction plan, suitable weather and sea conditions were selected, and construction vessels were positioned at the location of the suspended subsea pipeline requiring treatment. Divers and ROVs jointly lowered the cement grouting device, fixing the first grouting bag below the suspended pipeline, thus securing it between the pipeline and the seabed. Grouting was then performed on the first grouting bag, increasing its volume and providing support for the suspended pipeline. Once the pipeline was stably supported, grouting was stopped, and the pipeline was connected to the upper part of the first grouting bag using a fixing mechanism, maintaining a stable relative position and ensuring the pipeline's stability. Furthermore, if the pipeline experiences a secondary suspension, cement grout can be injected into the first grouting bag again, increasing its volume and providing further support for the secondary suspension. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the fixing mechanism of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure at the connection point of the cylinder in this invention;

[0027] Figure 4 This is a schematic diagram of the steel reinforcement cage of the present invention.

[0028] icon:

[0029] 100. First grouting bag; 110. Second grouting bag; 120. Spare grouting bag; 130. Grouting pipe; 140. Backfill pipe; 150. Reinforcing steel cage; 160. Reinforcing rib; 200. Fixing mechanism; 210. First clamping block; 220. Second clamping block; 230. Arc groove; 240. Connecting rod; 250. Connecting plate; 300. Base; 310. Round hole; 320. Connecting cylinder; 330. Locking nut; 340. Washer; 350. Artificial straw mat. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Example

[0034] like Figure 1-4As shown, a cement grouting device for preventing erosion of a suspended subsea pipeline includes a first grouting bag 100, which is fixed to the seabed and located below the suspended position of the pipeline. A fixing mechanism 200 is fixedly installed on the upper part of the first grouting bag 100. When grout is injected into the first grouting bag 100, the volume of the first grouting bag 100 increases, thereby filling the gap between the pipeline and the seabed. After the pipeline is supported by the first grouting bag 100, the pipeline is fixed to the fixing mechanism 200, thereby fixing the pipeline to the first grouting bag 100.

[0035] The working mechanism of the anti-erosion cement grouting device provided in this embodiment is as follows:

[0036] After determining the location of the suspended subsea pipeline through engineering practice, a support plan for the anti-scour grouting device was formulated. Based on the construction plan, suitable weather and sea conditions were selected, and the construction vessel was positioned at the location of the suspended subsea pipeline requiring treatment. Divers and an ROV jointly lowered the cement grouting device, fixing the first grouting bag 100 below the suspended pipeline, thus securing it between the pipeline and the seabed. Grouting was then performed on the first grouting bag 100, causing it to increase in volume as it was filled with cement grout, thereby... The increased volume of the first grouting bag 100 can support the suspended pipe. Once the pipe is stably supported, grouting of the first grouting bag 100 is stopped, and the pipe is connected to the upper part of the first grouting bag 100 through the fixing mechanism 200, so that the relative position of the pipe and the first grouting bag 100 remains fixed, maintaining the effect of stable fixation of the pipe. At the same time, when the pipe is suspended for a second time, cement grout can be injected into the first grouting bag 100 again, so that the volume of the first grouting bag 100 increases again, thereby providing support for the pipe that is suspended for a second time.

[0037] Regarding the fixed mechanism 200, specifically:

[0038] The fixing mechanism 200 includes a first clamping block 210 and a second clamping block 220. Arc-shaped grooves 230 are provided on the opposite surfaces of the first clamping block 210 and the second clamping block 220. Connecting rods 240 are connected to both the first clamping block 210 and the second clamping block 220. A connecting plate 250 is connected to both sets of connecting rods 240. The connecting rods 240 are threaded to the corresponding first clamping block 210 and the second clamping block 220. The connecting plate 250 is provided with through grooves that cooperate with the connecting rods 240. When the connecting rods 240 are screwed onto the corresponding first clamping block 210 and the second clamping block 220, the connecting rods 240 can press the connecting plate 250 against the first clamping block 210 and the second clamping block 220, so that the first clamping block 210 and the second clamping block 220 can fix and clamp the pipe.

[0039] The first clamping block 210 and the second clamping block 220 serve as the main clamping components. Both of their opposing surfaces are designed with arc-shaped grooves 230. The shape and size of these arc-shaped grooves 230 are customized according to the diameter or shape of the pipe to be fixed, ensuring a tight fit during clamping and reducing slippage or loosening. Connecting rods 240 are respectively connected to the first clamping block 210 and the second clamping block 220. These connecting rods 240 are threaded, meaning they can be tightened or loosened by rotation. A connecting plate 250 is located between the two sets of connecting rods 240 and has through slots corresponding to the connecting rods 240. These through slots allow the connecting rods to... 240 passes through and serves as a guide and limiting structure when the connecting rod 240 rotates. When fixing the pipe, the pipe is first placed in the arc groove 230 of the two clamping blocks, and the two clamping blocks are pushed close to ensure that the pipe fits in the arc groove 230. Then, by rotating the connecting rod 240, the connecting rod 240 is gradually tightened in the first clamping block 210 and the second clamping block 220. Since the connecting rod 240 is threaded, the end pin of the connecting rod 240 presses against the connecting plate 250 during the rotation, so that the connecting plate 250 is pressed against the two clamping blocks. Under the action of friction, the position of the two clamping blocks is fixed, and the pipe is clamped and fixed at the same time.

[0040] Regarding how the first grouting bag 100 is fixed to the seabed, specifically:

[0041] It also includes a base 300, a first grouting bag 100 fixedly connected to the base 300, and round holes 310 are provided at the four corners of the base 300. A connecting cylinder 320 is inserted into the round hole 310 and passes through the round hole 310 and is inserted into the seabed.

[0042] To prevent the cement grouting device from being affected by waves and currents, four round holes 310 are opened at the four corners of the base 300. The connecting cylinder 320 is inserted into the seabed through the round holes 310. The lower end of the connecting cylinder 320 has a rivet structure, which makes it easy to drive into the seabed.

[0043] Among the optional methods in this embodiment, the more preferred one is:

[0044] The top of the connecting cylinder 320 is threaded and a locking nut 330 is connected to it via the thread. A washer 340 is placed at the bottom of the locking nut 330. Tightening the locking nut 330 can fix the base 300 to the connecting cylinder 320.

[0045] The upper end of the connecting cylinder 320 is threaded, and the washer 340 is fitted onto the lower part of the thread of the connecting cylinder 320. The nut is screwed onto the thread to fix the connecting cylinder 320, thereby locking the base 300 onto the connecting cylinder 320. The connecting cylinder 320 is inserted into the seabed to a depth of about 5-10m.

[0046] Among the optional methods in this embodiment, the more preferred one is:

[0047] An artificial grass mat 350 is laid on the base 300. The artificial grass mat 350 is made of strips of artificial grass woven from erosion-resistant material.

[0048] The purpose of the artificial grass mat 350 is to prevent secondary suspension of the submarine pipeline caused by ocean current erosion. The artificial grass mat 350 is woven from artificial grass, which is made of one of the anti-erosion materials such as polypropylene or polyester. It is circular in shape, with a diameter of 3-5mm and a length of 400-600mm. The artificial grass is made into artificial grass mat 350 and fixed to the steel plate base 300 with a special adhesive. The anti-erosion material is polypropylene or polyester, etc.

[0049] Among the optional methods in this embodiment, the more preferred one is:

[0050] The upper part of the first grouting bag 100 is connected to the second grouting bag 110.

[0051] The main function of the second grouting bag 110 is to inject grout into the second grouting bag 110 when the height of the first grouting bag 100 is insufficient to meet the span height of the submarine pipeline, so that the second grouting belt can be adjusted to make up for the insufficient height of the first grouting bag 100.

[0052] Among the optional methods in this embodiment, the more preferred one is:

[0053] The upper part of the second grouting bag 110 is connected to a spare grouting bag 120.

[0054] When the height of the first grouting bag 100 is insufficient to meet the requirements of the second grouting bag 110 for the span height of the submarine pipeline, the function of the spare grouting bag 120 is to inject grout into the spare grouting bag 120 when the pipeline experiences a secondary span, so that the pipeline continues to be supported. When the first grouting bag 100 is not full of grout, the first grouting bag 100 can serve as the spare grouting bag 120. If the first grouting bag 100 is full of grout, but the second grouting bag 110 is not full, the second grouting bag 110 can serve as the spare grouting bag 120. In addition, the number of spare grouting bags 120 can be increased or decreased as appropriate according to the span height.

[0055] All of the above-mentioned grouting bags are made of either polypropylene or polyurethane, and are manufactured using heat sealing and sewing processes to ensure sufficient strength and sealing.

[0056] Among the optional methods in this embodiment, the more preferred one is:

[0057] The first grouting bag 100, the second grouting bag 110, and the spare grouting bag 120 are all connected to a grouting pipe 130 and a return grouting pipe 140. Cement grout is injected through the grouting pipe 130, and after the corresponding grouting bag is filled with cement grout, the cement grout is discharged through the return grouting pipe 140.

[0058] The grouting pipe 130 facilitates the injection of cement slurry into the grouting bag. After the grouting device is placed on the subsea pipeline to be treated and lowered, the grouting bag is then filled. One end of the grouting hose interface on the work vessel is connected by a diver or ROV to the grouting pipe 130 of the first grouting bag 100 of the grouting bag device lowered on the subsea pipeline. The grouting operation is then carried out. When the return pipe detects the return of cement slurry and the subsea pipeline to be treated is fully supported in place, the grouting is stopped and the grouting operation is completed. The diver or ROV disconnects the grouting hose from the grouting bag, cleans the grouting hose, and takes it to the construction vessel for recovery.

[0059] After the pipeline is fixed on the fixing mechanism 200, the connecting column 320 is driven into the seabed through the round hole 310 of the base 300 using the piling equipment on the construction vessel. Divers or ROVs then tighten the nuts to fix the base 300 and stabilize the entire anti-scour cement grouting device. Finally, the cleaning and finishing work is carried out to complete the work of using the anti-scour cement grouting device to treat the suspended subsea pipeline.

[0060] Among the optional methods in this embodiment, the more preferred one is:

[0061] A first check valve is installed on the grouting pipe 130, and a second check valve is installed on the backflow pipe 140. The opening pressure of the second check valve is greater than or equal to 0.05 MPa and less than or equal to 0.15 MPa.

[0062] The first check valve prevents the injected slurry from flowing back through the grouting pipe 130. The second check valve has an opening pressure greater than or equal to 0.05 MPa and less than or equal to 0.15 MPa, ensuring that the cement slurry injected into the grouting bag will not leak out before it is fully filled.

[0063] Among the optional methods in this embodiment, the more preferred one is:

[0064] The first grouting bag 100, the second grouting bag 110 and the spare grouting bag 120 are all connected to a steel reinforcement cage 150, and the steel reinforcement cage 150 is internally connected to multiple reinforcing ribs 160 arranged horizontally and vertically.

[0065] The steel reinforcement cage 150 is internally welded with horizontal and longitudinal reinforcing bars 160 for support. The reinforcing bars 160 are made of HPB235 steel bars with a diameter of 6-10mm, which improves the structural strength of the grouting bag after grouting.

[0066] 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cement grouting device for preventing erosion during the treatment of suspended submarine pipelines, characterized in that: The utility model provides a pipeline fixing device, which comprises a first grouting bag (100) fixed to the seabed and located below the suspension position of the pipeline, and a fixing mechanism (200) arranged at the upper part of the first grouting bag (100). When grouting is performed in the first grouting bag (100), the volume of the first grouting bag (100) increases to fill the gap between the pipeline and the seabed, and the pipeline is fixed to the fixing mechanism (200) after being supported by the first grouting bag (100), so that the pipeline is fixed to the first grouting bag (100).

2. The anti-scour cement grouting device for governing the pipeline's overhang on the seabed according to claim 1, characterized in that: The fixing mechanism (200) comprises first clamping blocks (210) and second clamping blocks (220), arc-shaped grooves (230) are formed on the opposite surfaces of the first clamping blocks (210) and the second clamping blocks (220), and connecting rods (240) are connected to the first clamping blocks (210) and the second clamping blocks (220). The connecting rods (240) are screwed into the first clamping blocks (210) and the second clamping blocks (220), and through grooves are formed in the connecting plate (250) to cooperate with the connecting rods (240), so that the connecting rods (240) can press the connecting plate (250) against the first clamping blocks (210) and the second clamping blocks (220) when the connecting rods (240) are screwed into the first clamping blocks (210) and the second clamping blocks (220), and the first clamping blocks (210) and the second clamping blocks (220) can clamp and fix the pipeline.

3. The anti-scour cement grouting device for governing the overhang of a submarine pipeline according to claim 2, characterized in that: The first grouting bag (100) is fixedly connected to a base (300), circular holes (310) are formed in the four corners of the base (300), connecting cylinders (320) are inserted into the circular holes (310), and the connecting cylinders (320) penetrate through the circular holes (310) and are inserted into the seabed.

4. The anti-scour cement grouting device for governing the pipeline's overhang on the seabed according to claim 3, characterized in that: The top end of the connecting cylinder (320) is provided with threads, and a locking nut (330) is connected to the threads, and a gasket (340) is arranged at the lower part of the locking nut (330). The base (300) is fixed to the connecting cylinder (320) by screwing the locking nut (330).

5. The anti-scour cement grouting device for governing the pipeline's overhang on the seabed according to claim 4, characterized in that: An artificial grass mat (350) is arranged on the base (300), and the artificial grass mat (350) is made of strip-shaped artificial grass woven from an anti-erosion material.

6. The anti-scour cement grout for governing the pipeline's overhang on the seabed as claimed in claim 5, wherein: A second grouting bag (110) is connected to the upper part of the first grouting bag (100).

7. The anti-scour cement grout for governing the pipeline's overhang on the seabed as claimed in claim 6, wherein: A standby grouting bag (120) is connected to the upper part of the second grouting bag (110).

8. The anti-scour cement grout for governing the pipeline's overhang on the seabed as claimed in claim 7, wherein: Grouting pipes (130) and reverse grouting pipes (140) are connected to the first grouting bag (100), the second grouting bag (110), and the standby grouting bag (120), cement grout is injected through the grouting pipes (130), and the cement grout is discharged through the reverse grouting pipes (140) after the corresponding grouting bags are filled with the cement grout.

9. The anti-scour cement grout for governing the pipeline's overhang of the seabed according to claim 8, characterized in that: The grouting pipe (130) is provided with a first one-way valve, and the anti-grouting pipe (140) is provided with a second one-way valve, and the opening pressure of the second one-way valve is greater than or equal to 0.05 MPa and less than or equal to 0.15 MPa.

10. The anti-scour cement grout for governing the pipeline's overhang on the seabed as claimed in claim 9, wherein: The first grouting bag (100), the second grouting bag (110) and the standby grouting bag (120) are connected with a steel reinforcement cage (150), and the steel reinforcement cage (150) is internally connected with a plurality of transversely and longitudinally arranged reinforcing ribs (160).

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