Offshore platform pile simulation device and simulation method

Abstract

This invention relates to a simulation device for offshore platform piles, comprising a pile core, a pile sleeve, and a counterweight. The pile sleeve is fitted over the pile core, and the pile sleeve and pile core are rigidly connected. A water-storage cavity exists between the pile sleeve and the pile core. The counterweight is mounted on the pile core. The simulation device needs to be configured according to the actual offshore platform pile design. The counterweight primarily serves to eliminate the mass difference between the simulation device and the actual offshore platform pile. For example, during testing, the simulation device is submerged in a water tank, and water is simultaneously filled into the water-storage cavity. The water tank simulates the hydro-structure interaction between ocean currents and waves, allowing for a safety assessment of offshore piling operations through hydrodynamic testing of steel piles. This is of significant importance for guiding engineering practice.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a device and method for simulating the pile body of a marine platform. Background Technology

[0002] In recent years, with the rapid economic development and increasing energy demand in various regions, offshore oil and gas resource development has made continuous progress, and operating water depths have been increasing. Fixed offshore platforms remain the main method for near-shore oil and gas development. Jacket platforms rely on multiple steel piles driven around each leg on the seabed for fixation. Due to the increasing operating water depth, the length and diameter of the steel piles are also constantly increasing. During the piling operation, the steel piles are subjected to hydrostructure dynamic coupling with the surrounding ocean currents and waves, thus affecting operational safety. Currently, there is no experimental device capable of assessing the safety of offshore piling operation schemes; therefore, there is an urgent need for an experimental device capable of simulating the operation to assess the safety of the scheme before conducting offshore piling operations. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a marine platform pile simulation device and simulation method, establishing a highly versatile steel pile testing device capable of simulating offshore pile driving operations.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A marine platform pile simulation device, comprising:

[0006] Pile core;

[0007] A pile sleeve is fitted over the outside of the pile core and is rigidly connected to the pile core. A water storage cavity is provided between the pile sleeve and the pile core.

[0008] A counterweight is disposed on the pile core.

[0009] In one embodiment, the pile sleeve is segmented, with the pile sleeve vertically divided into multiple component segments, each of which is rigidly connected to the corresponding pile core.

[0010] In one embodiment, an expansion joint is provided between adjacent kit segments.

[0011] In one embodiment, each end of the kit segment is provided with a connecting ring, and the kit segment is rigidly connected to the corresponding pile core through the connecting ring.

[0012] In one embodiment, each of the expansion joints is provided with a soft seal to seal the expansion joint.

[0013] In one embodiment, multiple counterweights are provided, and the counterweights are evenly distributed along the circumference of the pile core.

[0014] In one embodiment, multiple counterweights at the same height form a counterweight group;

[0015] Each of the kit segments has a corresponding pile core area equipped with the balancing unit.

[0016] In one embodiment, the reassembly unit is located in the middle of the corresponding kit segment.

[0017] This invention also provides a method for simulating the piles of an offshore platform, comprising the following steps:

[0018] Based on the relationship between the offshore platform pile and the scaled-down test, the bending stiffness, mass per unit length, and outer diameter were determined as the design target values ​​for the simulation device.

[0019] The materials for the pre-selected pile core and pile sleeve are calculated based on the target values ​​of bending stiffness and outer diameter through experimental scaling relationships.

[0020] Install the pile core and the pile sleeve, and fit the pile sleeve over the outside of the pile core to rigidly connect the pile core and the pile sleeve. A water storage cavity is left between the pile core and the pile sleeve.

[0021] Compare the simulation results with the design target values;

[0022] If the mass of the simulation device is greater than the design target value, then the material and size scheme of the pile core and the pile sleeve shall be adjusted.

[0023] If the mass of the simulation device is less than the design target value, then a counterweight is designed based on the difference between the two.

[0024] In one embodiment, when the diameter of the pile core and the outer diameter of the pile sleeve are calculated based on the target values ​​of bending stiffness and outer diameter using experimental scaling relationships, the pile sleeve is divided into multiple component segments, with each component segment rigidly connected to its corresponding pile core at both ends.

[0025] The present invention has the following advantages due to the adoption of the above technical solutions:

[0026] The simulation device simulates the rigidity and strength of offshore platform piles through the pile core, while the pile sleeve simulates geometric similarity, and the counterweight simulates mass similarity. This achieves geometric, mass, and stiffness similarity, enabling accurate simulation of fluid loads and structural modes. To ensure a more accurate comparison between the simulation device and the offshore platform piles, a water-filled cavity is placed between the pile sleeve and the pile core. During testing, the simulation device is submerged in a water tank, and water is simultaneously filled into the cavity. The water tank simulates the hydro-structure interaction between ocean currents and waves, allowing for a safety assessment of offshore piling operations through hydrodynamic testing of steel piles. This is of significant importance for guiding engineering practice. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the specific structure of the simulation device in one embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the specific structure of the kit segment in one embodiment of the present invention;

[0029] Figure 3 yes Figure 2 Sectional view at point A in the middle;

[0030] Figure 4 yes Figure 2 Sectional view at point B;

[0031] The markings in the diagram are as follows:

[0032] 1. Pile core; 2. Pile sleeve; 3. Counterweight; 4. Soft seal; 5. Water storage cavity; 6. Connecting ring. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," "third," "fourth," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0035] Fixed offshore platforms remain the primary method for near-shore oil and gas development. Jacket platforms are secured by driving multiple steel piles around each leg on the seabed. Currently, there is no testing device capable of assessing the safety of offshore piling operations; therefore, there is an urgent need for a testing device capable of simulating the operation to evaluate the safety of the plan before offshore piling work. To address the existing technical problems, this invention provides an offshore platform pile simulation device and method, establishing a highly versatile steel pile testing device capable of simulating offshore piling operations.

[0036] The technical solution of the present invention will be described in detail below with reference to specific examples.

[0037] Reference Figure 1 as well as Figure 2 As shown, the present invention relates to a marine platform pile simulation device, which includes a pile core 1, a pile sleeve 2 and a counterweight 3. The pile sleeve 2 is sleeved on the outside of the pile core 1 and is rigidly connected to the pile core 1. There is a water storage cavity 5 between the pile sleeve 2 and the pile core 1. The counterweight 3 is disposed on the pile core 1.

[0038] It should be noted that during piling operations, the steel piles are subjected to hydro-structure dynamic coupling with the surrounding ocean currents and waves, which can affect operational safety. A simulation device was designed and placed into a hydrodynamic test of the steel piles to assess the safety of the offshore piling operation.

[0039] Hydrodynamic testing of steel piles differs significantly from hydrodynamic performance testing of general offshore platforms. In the latter, the platform is simulated as a rigid body, its stiffness disregarded. In contrast, the simulation device in the former is a flexible body, and the research object is the dynamic coupling characteristics between the hydrodynamic loads on the steel piles and the strain of the structural body. Accurate simulation of the device in the water tank model test is crucial to the test results and is also the most challenging aspect of the entire experiment.

[0040] The simulation device must simultaneously satisfy the following three similarities:

[0041] 1) Geometric similarity, satisfying the geometric similarity of the steel pile length and outer diameter;

[0042] 2) Similar mass, satisfying the requirement that the mass per unit length of the steel piles is similar, which includes both the mass of the stiffness itself and the mass of the seawater inside the steel pipe;

[0043] 3) Similar stiffness, the bending stiffness of the steel piles is similar.

[0044] The similarity relationships in these three aspects must be satisfied simultaneously to achieve accurate simulation of fluid loads and structural modes. Furthermore, since steel piles are typically made of steel, it is difficult to find materials that simultaneously satisfy the density and elastic modulus scaling relationships if direct geometric similarity design is used for the steel pile's shape in hydrodynamic testing.

[0045] Since the actual offshore platform piles are hollow steel pipe pile structures, it is difficult to find materials that can simultaneously satisfy the density and elastic modulus scaling relationship during simulation tests. Therefore, this scheme simulates the offshore platform piles and compares the simulation device with the offshore platform piles to satisfy geometric similarity, mass similarity, and stiffness similarity, so as to achieve accurate simulation of fluid load and structural modes.

[0046] For example, in this embodiment, the simulation device simulates the rigidity and strength of the offshore platform pile through the pile core 1, while the pile sleeve 2 simulates geometric similarity. Additionally, the counterweight 3 simulates mass similarity, achieving geometric, mass, and stiffness similarity, thus enabling accurate simulation of fluid loads and structural modes. To ensure a more accurate comparison between the simulation device and the offshore platform pile, a water-storage cavity 5 is provided between the pile sleeve 2 and the pile core 1. During the test, the simulation device is submerged in a water tank, and water is simultaneously filled into the water-storage cavity 5. The water tank simulates the hydro-structure interaction between ocean currents and waves, allowing for a safety assessment of offshore piling operations through steel pile hydrodynamic testing. This is of significant importance for guiding engineering practice.

[0047] In one embodiment, in order to achieve the above similarity simulation, when designing the simulation device, the similarity reconstruction is carried out for the research object, that is, the configuration design of the steel pile hydrodynamic test is carried out using multiple materials and combinations.

[0048] In this embodiment, it should be noted that the test scale is not a fixed value in this scheme. The operator can select a suitable test scale according to the actual situation. The next step is to determine the bending stiffness, mass per unit length, and outer diameter as the design target values ​​of the simulation device based on the relationship between the offshore platform pile and the test scale. The materials of the pile core 1 and pile sleeve 2 are pre-selected, and the diameter of the pile core 1 and the outer diameter of the pile sleeve 2 are calculated based on the target values ​​of bending stiffness and outer diameter through the test scale relationship.

[0049] The process involves dividing the pile sleeve 2 into multiple modular segments. Each segment is rigidly connected at both ends to its corresponding pile core 1. The pile core 1 and pile sleeve 2 are then installed, with the pile sleeve 2 fitted over the pile core 1, rigidly connecting them. A water-storage cavity 5 is left between the pile core 1 and the pile sleeve 2. Simultaneously, the simulated device's mass is compared to the design target. If the simulated device's mass is greater than the design target, the materials and dimensions of the pile core 1 and pile sleeve 2 are adjusted. If the simulated device's mass is less than the design target, a counterweight 3 is designed based on the difference. The goal is to ensure that the total mass of the simulated device's pile core 1, pile sleeve 2, counterweight 3, and the water filling the water-storage cavity 5 is similar to the total mass of the offshore platform pile and the seawater within it.

[0050] Reference Figure 3 as well as Figure 4 As shown, it should be noted that in this embodiment, the pile sleeve 2 is simulated using a PVC material shell, and its diameter is geometrically similar to the actual object. To avoid the outer wall affecting the structural rigidity, it is simulated in segments, with the entire pile sleeve 2 divided into several component segments. Specifically, each component segment has a connecting ring 6 at both ends, and the component segment is rigidly connected to the corresponding pile core 1 through the connecting ring 6. In order to connect the water storage cavities 5 in adjacent component segments, the connecting ring 6 is provided with a connecting hole. The rigid connection can be a bolted connection or a welded connection, etc., and is not further limited here.

[0051] More preferably, in this embodiment, to avoid interference between the micro-movements of adjacent component segments, expansion joints are provided between adjacent component segments. Simultaneously, to achieve sealing, each expansion joint is equipped with a soft seal 4 to seal the expansion joint.

[0052] In this embodiment, to ensure a more uniform overall weight distribution of the pile core 1, multiple counterweights 3 are provided, evenly distributed along the circumference of the pile core 1. Furthermore, in this embodiment, multiple counterweights 3 at the same height form a counterweight group, and each segment of the pile core 1 has a counterweight group located in the center of the corresponding segment. Therefore, the weight requiring counterweight distribution is evenly distributed across the overall structure of the pile core 1, further optimizing the weight uniformity of the pile core 1.

[0053] This invention also provides a method for simulating the piles of an offshore platform, comprising the following steps:

[0054] Based on the relationship between the offshore platform pile and the scaled-down test, the bending stiffness, mass per unit length, and outer diameter were determined as the design target values ​​for the simulation device.

[0055] The materials for the pre-selected pile core 1 and pile sleeve 2 are calculated based on the target values ​​of bending stiffness and outer diameter through experimental scaling relationships.

[0056] Install pile core 1 and pile sleeve 2, put pile sleeve 2 on the outside of pile core 1, rigidly connect pile core 1 and pile sleeve 2, and leave a water storage cavity 5 between pile core 1 and pile sleeve 2.

[0057] Compare the simulation device with the design target values;

[0058] If the mass of the simulation device is greater than the design target value, the material and size scheme of pile core 1 and pile sleeve 2 shall be adjusted.

[0059] If the mass of the simulation device is less than the design target value, then counterweight 3 is designed based on the difference between the two.

[0060] Even better, in order to facilitate the construction of the pile sleeve 2, the materials of the pile core 1 and the pile sleeve 2 are pre-selected. When the diameter of the pile core 1 and the outer diameter of the pile sleeve 2 are calculated by experimental scaling relationship based on the target values ​​of bending stiffness and outer diameter, the pile sleeve 2 is divided into multiple kit segments, and the two ends of the kit segments are rigidly connected to the corresponding pile core 1 respectively.

[0061] 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 device for simulating the pile body of an offshore platform, characterized in that, include: Pile core; A pile sleeve is fitted over the outside of the pile core and is rigidly connected to the pile core. A water storage cavity is provided between the pile sleeve and the pile core. A counterweight is disposed on the pile core.

2. The offshore platform pile simulation device according to claim 1, characterized in that: The pile sleeve is segmented, with the pile sleeve vertically divided into multiple component segments, each of which is rigidly connected to the corresponding pile core.

3. The offshore platform pile simulation device according to claim 2, characterized in that, Expansion joints are provided between adjacent kit segments.

4. The offshore platform pile simulation device according to claim 3, characterized in that, Both ends of the kit segment are provided with connecting rings, and the kit segment is rigidly connected to the corresponding pile core through the connecting rings.

5. The offshore platform pile simulation device according to claim 3, characterized in that, Each of the expansion joints is provided with a soft seal to seal the expansion joint.

6. The offshore platform pile simulation device according to claim 2, characterized in that, Multiple counterweights are provided, and the counterweights are evenly distributed along the circumference of the pile core.

7. The offshore platform pile simulation device according to claim 6, characterized in that, Multiple counterweights at the same height form a counterweight group; Each of the kit segments has a corresponding pile core area equipped with the balancing unit.

8. The offshore platform pile simulation device according to claim 7, characterized in that, The reassembly unit is located in the middle of the corresponding kit segment.

9. A method for simulating the pile body of an offshore platform, characterized in that, Includes the following steps: Based on the relationship between the offshore platform pile and the scaled-down test, the bending stiffness, mass per unit length, and outer diameter were determined as the design target values ​​for the simulation device. The materials for the pre-selected pile core and pile sleeve are calculated based on the target values ​​of bending stiffness and outer diameter through experimental scaling relationships. Install the pile core and the pile sleeve, and fit the pile sleeve over the outside of the pile core to rigidly connect the pile core and the pile sleeve. A water storage cavity is left between the pile core and the pile sleeve. Compare the simulation results with the design target values; If the mass of the simulation device is greater than the design target value, then the material and size scheme of the pile core and the pile sleeve shall be adjusted. If the mass of the simulation device is less than the design target value, then a counterweight is designed based on the difference between the two.

10. The method for simulating offshore platform piles according to claim 9, characterized in that: The materials of the pre-selected pile core and pile sleeve are calculated based on the bending stiffness and outer diameter target values ​​through experimental scaling relationship to obtain the diameter of the pile core and the outer diameter of the pile sleeve. The pile sleeve is divided into multiple kit segments, and the two ends of the kit segments are rigidly connected to the corresponding pile cores.

Images