Keel node protection device, keel node assembly, top-tensioned riser, production platform, and method of designing a keel node assembly

Abstract

The application provides a keel node protection device, a keel node assembly, a top-tensioned riser, an oil production platform and a keel node assembly design method. The keel node protection device comprises a mounting seat, a plurality of supports and a plurality of elastic bodies. The mounting seat is used for sleeving the outer side of a smooth transition section of a keel node. The keel node is used for connecting between two adjacent production risers of a top-tensioned riser. The outer diameter of the smooth transition section of the keel node is constant. The plurality of supports are distributed in the circumferential direction of the mounting seat. One end of each support is connected with the mounting seat. The other end of the support extends away from the mounting seat in the radial direction of the mounting seat. The plurality of elastic bodies are arranged one by one at the ends of the plurality of supports away from the mounting seat. When the platform body collides with the top-tensioned riser during relative movement, the elastic body will be in contact with the keel inner wall of the platform body. The elastic body can weaken the mechanical transmission between rigid structures caused by relative displacement, so as to achieve the purpose of protecting the keel node from being damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas production equipment, and particularly relates to a keel node protection device, a keel node assembly, a top-tensioned riser, an oil production platform and a keel node assembly design method. BACKGROUND

[0002] In recent years, with the development of exploration and development technology, marine oil and gas gradually moves from shallow water to deep water, and becomes an important growth pole in the energy consumption structure. As a bridge connecting the underwater production system and the platform, the riser often faces challenges such as waves, currents and platform movements. The top-tensioned riser is a relatively representative type of riser system, and the supporting production scheme is widely adopted on the tension leg platform or single column (SPAR) platform. In field application, the top-tensioned riser is fixedly connected at both ends with a rigid structure, and is in a vertical and taut state, so that the flexibility is obviously weakened. When the platform fluctuates and deviates with the waves, the riser passing through the keel of the platform may be damaged due to sudden increase of local stress. Especially considering the particularity of the dry tree platform and the top-tensioned riser structure design, the stress peak value often appears at the keel joint part of the top-tensioned riser in contact with the main body of the platform, which is easy to cause damage to the top-tensioned riser. SUMMARY

[0003] The present application aims to at least solve one of the problems in the prior art. To this end, the present application provides a keel node protection device, a keel node assembly, a top-tensioned riser, an oil production platform and a keel node assembly design method, which aims to solve the problem that the keel joint of the top-tensioned riser in contact with the main body of the platform is subjected to a large force and is prone to damage.

[0004] The present application provides a keel node protection device, which comprises:

[0005] A mounting seat, which is used for sleeving the outer side of a smooth transition section of a keel node, the keel node being used for connecting between two adjacent production risers of a top-tensioned riser;

[0006] A plurality of supports, which are distributed in the circumferential direction of the mounting seat, and one end of each support is connected with the mounting seat, and the other end of the support extends away from the mounting seat in the radial direction of the mounting seat;

[0007] A plurality of elastic bodies, which are one-to-one correspondingly arranged at the end of the plurality of supports away from the mounting seat.

[0008] According to the keel node protection device provided by the present application, the elastic body is formed by alternately stacking metal plates and elastic washers, and the metal plates and the elastic washers are both perpendicular to the axis of the support.

[0009] According to the keel node protection device provided by the application, the metal plate is arranged on the side of the elastic body close to the support and the side of the elastic body away from the support.

[0010] According to the keel node protection device provided by the application, the metal plate is made of a steel plate or a titanium alloy plate, and the elastic gasket is made of rubber.

[0011] The application further provides a keel node assembly, comprising:

[0012] The keel node comprises a top tapered section, a smooth transition section and a bottom tapered section from top to bottom, the large end of the top tapered section and the large end of the bottom tapered section are connected with the two end portions of the smooth transition section respectively, the outer diameter of the smooth transition section is constant, and the inner diameter of the keel node is constant.

[0013] The mounting seat of the keel node protection device is sleeved on the outer side of the smooth transition section of the keel node.

[0014] According to the keel node assembly provided by the application, the keel node is made of steel or titanium alloy.

[0015] According to the keel node assembly provided by the application, the keel node is integrally forged and formed, or the top tapered section is connected with the smooth transition section, and the smooth transition section is connected with the bottom tapered section by welding.

[0016] The application further provides a top-tensioned riser, comprising a plurality of production riser singles and the keel node assembly as described above, and the keel node assembly is arranged between two of the production riser singles.

[0017] The application further provides an oil production platform, comprising a platform body and the top-tensioned riser as described above, the top of the top-tensioned riser is arranged above the platform body through the keel of the platform body, and the smooth transition section of the keel node of the top-tensioned riser corresponds to the keel position.

[0018] The application further provides a design method of a keel node assembly, which is used for designing the keel node assembly as described above, and the design method comprises the following steps:

[0019] According to the motion characteristics and environmental parameters of the platform body, the maximum offset between the platform body and the top-tensioned riser is predicted , the maximum stress between the platform body and the top-tensioned riser is determined based on the maximum offset , and a safety coefficient is preset ;

[0020] the maximum stress between the platform body and the top-tensioned riser is determined based on the maximum offset​ and the aforementioned safety factor The effective bearing area of ​​the elastomer is determined as follows: , satisfy , This represents the average compressive stress limit during the working period of the support.

[0021] Preset shear deformation caused by external compression The total thickness of the elastic gasket is determined to be , satisfy ;

[0022] Based on the total thickness of the elastic gasket Determine the side length of the support. or diameter When the cross-section of the support is rectangular, the side length of the support is... satisfy When the cross-section of the support is circular, the diameter of the support is... satisfy ;

[0023] Based on the maximum stress The safety factor 'a' and the effective pressure-bearing area of ​​the elastomer. Determine the thickness of a single metal plate. The thickness of the elastic pad located on the upper layer of the metal plate and the thickness of the elastic gasket located under the metal plate The thickness of a single metal plate The thickness of the elastic gasket located on the upper layer of the metal plate The thickness of the elastic gasket located under the metal plate ,and ;

[0024] Obtain the inner diameter of a single production riser for a top-tensioned riser. and outer diameter Effective offset distance of the keel of the oil production platform And based on the inner diameter of the single production riser. and outer diameter Determine the inner diameter of the keel node. The outer diameter of the connection point between the keel node and the single production riser pipe Based on the effective offset distance of the keel of the oil production platform Determine the length of the smooth transition section of the keel node. ,in, , , ;

[0025] obtaining the inner diameter of the keel of the platform body , and presetting the length of the support as , determining the outer diameter of the smooth transition section of the keel node based on the inner diameter of the keel of the platform body , the total thickness of the elastic pad , the thickness of a single piece of the metal plate and the length of the support , the outer diameter of the smooth transition section of the keel node satisfies ;

[0026] determining the curvature of the connection between the keel node and the production riser single piece based on the outer diameter of the connection between the keel node and the production riser single piece and the outer diameter of the smooth transition section of the keel node and the curvature of the end of the smooth transition section of the keel node , the curvature of the connection between the keel node and the production riser single piece and the curvature of the end of the smooth transition section of the keel node satisfy ;

[0027] checking whether the keel node is damaged when the oil production platform rises and falls with the waves, deviates and rotates to produce the maximum stress peak, and if the keel node is damaged, the design parameters are replaced and the above steps are repeated until the keel node is no longer damaged.

[0028] The present application has the following advantages due to the above technical solutions:

[0029] The keel node protection device provided by the present application comprises a mounting seat, a plurality of supports and a plurality of elastic bodies. The mounting seat is used for sleeving the outer side of the smooth transition section of the keel node, and the keel node is used for connecting between two adjacent production riser single pieces of the top tension riser. The plurality of supports are distributed along the circumference of the mounting seat, and one end of each support is connected with the mounting seat, and the other end of the support extends away from the mounting seat in the radial direction of the mounting seat. The plurality of elastic bodies are one-to-one corresponding to the ends of the plurality of supports away from the mounting seat. When the platform body and the top tension riser move relatively and collide, the elastic body will first contact the inner wall of the keel of the platform body, and the elastic body will weaken the mechanical transmission between rigid structures caused by relative displacement, thereby achieving the purpose of protecting the keel node from being damaged.

[0030] Further, in the keel node assembly, the top tension riser and the oil production platform provided by the present application, since the keel node protection device as described above is provided, the same advantages as described above are achieved.​​

[0031] Further, in the keel node protection assembly design method provided by the application, since the keel node assembly is used for setting the keel node assembly as described above, the designed keel node assembly has the same advantages as described above. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0033] Figure 1 is a front view of the keel node assembly provided by an embodiment of the application;

[0034] Figure 2 is a top view of the keel node assembly provided by an embodiment of the application;

[0035] Figure 3 is Figure 2 is an enlarged view of A in FIG. 4.

[0036] Reference signs:

[0037] 100: mounting seat; 200: support; 300: elastic body; 310: metal plate; 320: elastic gasket; 410: top conical section; 420: smooth transition section; 430: bottom conical section. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the application clearer, the technical solutions in the application will be described clearly and completely below in combination with the drawings in the application. Obviously, the described embodiments are some of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0039] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated thereby must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated thereby. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0041] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0043] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0044] The present application provides a keel node protection device, the keel node is used for connecting between two adjacent production risers of a top tensioned riser, and a smooth transition section is arranged in the middle of the keel node. The keel node protection device comprises a mounting seat, a plurality of supports and a plurality of elastic bodies. The mounting seat is used for sleeving the outside of the smooth transition section of the keel node. The plurality of supports are uniformly distributed along the circumference of the smooth transition section of the keel node, and one end of each support is connected with the mounting seat, and the other end extends away from the mounting seat in the radial direction of the keel node. The plurality of elastic bodies are arranged one by one at the end of the plurality of supports away from the mounting seat. The keel node protection device provided by the present application can be used for protecting the keel node from being damaged when the platform body collides with the top tensioned riser in relative motion. When the elastic body contacts the inner wall of the keel, the force is transmitted to the keel node through the support and the mounting seat. Since the elastic body is arranged, compared with the hard collision between the keel node and the keel, the contact between the elastic body and the keel can weaken the mechanical transmission caused by the relative displacement between the rigid structures, so as to achieve the purpose of protecting the keel node from being damaged.

[0045] The keel node protection device of the present application will be described below. Figures 1 to 3 The keel node protection device of the present application will be described below.

[0046] The embodiment of the present application provides a keel node protection device, which comprises a mounting seat 100, a plurality of supports 200 and a plurality of elastic bodies 300.

[0047] The mounting seat 100 is used for sleeving the outside of the smooth transition section 420 of the keel node, and the keel node is used for connecting between two adjacent production risers of a top tensioned riser.

[0048] Specifically, the outer diameter of the smooth transition section 420 of the keel node remains constant in the axial direction, so that the mounting seat 100 can be a cylindrical structure. The inner diameter of the mounting seat 100 can be equal to the outer diameter of the smooth transition section 420 of the keel node. In this way, the mounting seat 100 can be sleeved on the outside of the smooth transition section 420 of the keel node.

[0049] The plurality of supports 200 are distributed along the circumference of the mounting base 100, and one end of each support 200 is connected to the mounting base 100, and the other end of the support 200 extends away from the mounting base 100 along the radial direction of the mounting base 100.

[0050] Specifically, the support 200 can be a rod-shaped structure, and the cross section of the support 200 can be square or circular, and of course can also be other shapes, such as a polygon such as a triangle, a pentagon, etc., or an oval, etc.

[0051] The plurality of supports 200 are uniformly distributed along the circumference of the mounting base 100, for example, six supports 200 can be provided, and adjacent two supports 200 are spaced apart by 60 degrees. One end of the support 200 is connected to the mounting base 100, for example, can be connected by welding, and the other end of the support 200 extends away from the mounting base 100 along the radial direction of the mounting base 100. Preferably, the axes of the plurality of supports 200 are located on the same plane, and the plane is perpendicular to the axis of the mounting base 100.

[0052] The plurality of elastic bodies 300 are one-to-one corresponding to the plurality of supports 200 away from the mounting base 100.

[0053] Specifically, one elastic body 300 is provided at the end of each support 200 away from the mounting base 100.

[0054] When the platform body fluctuates and deviates with the waves, the top-tensioned riser passing through the keel of the platform body will bend, and even collide and extrude with the platform body, and the stress peak will often appear at the keel node part of the top-tensioned riser in contact with the keel of the platform body, which is extremely easy to cause damage to the top-tensioned riser.

[0055] Currently, when the platform body and the top-tensioned riser move relatively, the keel of the platform body and the keel node of the top-tensioned riser will have a rigid collision and a rigid extrusion, and after the keel node protection device provided by the present application is sleeved outside the keel node, the force transmission between the keel of the platform body and the keel node of the top-tensioned riser is carried out through the protection device. Due to the provision of the elastic body 300, the elastic body 300 will weaken the mechanical transmission between the rigid structures caused by the relative displacement, thereby achieving the purpose of protecting the keel node from being damaged.

[0056] In some embodiments of the present application, the elastic body 300 is a laminated structure formed by alternately stacking and vulcanizing a plurality of metal plates 310 and a plurality of elastic gaskets 320.

[0057] Further, the side of the elastic body 300 close to the support 200 and the side of the elastic body 300 away from the support 200 are both metal plates 310.

[0058] The side of the elastic body 300 close to the support 200 is provided with a metal plate 310, so as to facilitate the welding connection between the elastic body 300 and the support 200. Since the elastic body 300 needs to be in contact with the keel of the platform body, in order to improve the wear resistance of the elastic body 300, the side of the elastic body 300 away from the support 200 is provided with a metal plate 310.

[0059] The material of the metal plate 310 can be a steel plate or a titanium alloy plate, and the material of the elastic gasket 320 can be rubber.

[0060] The embodiment of the present application also provides a keel node assembly, which comprises a keel node and a keel node protection device as described above.

[0061] The keel node comprises a top tapered section 410, a smooth transition section 420 and a bottom tapered section 430. The outer diameter of the smooth transition section 420 remains constant along the axial direction, i.e. the outer peripheral surface of the smooth transition section 420 is a cylindrical surface. The large end of the top tapered section 410 is connected to the top end of the smooth transition section 420, and the large end of the bottom tapered section 430 is connected to the bottom end of the smooth transition section 420. The two ends of the keel node are through, and the inner diameter thereof remains constant along the axial direction.

[0062] In other words, the outer diameter of the keel node gradually increases first, then remains constant, and then gradually decreases from the top to the bottom, the outer diameters of the two ends of the keel node are equal, and the channel in the keel node passes through the top tapered section 410, the smooth transition section 420 and the bottom tapered section 430, and the inner diameter thereof remains constant along the axial direction.

[0063] The top end of the keel node and the bottom end of the keel node are respectively used for connecting with the end portions of two production riser joints, which requires that the outer diameter of the end portion of the keel node is equal to the outer diameter of the production riser joint, and the inner diameter of the keel node is equal to the inner diameter of the production riser joint.

[0064] The keel node is spindle-shaped, the outer diameter of the end portion connected with the production riser joint is the same as the outer diameter of the production riser joint, the outer diameter gradually increases in the direction of the smooth transition section 420, the structure is simple, the forging is facilitated, the bending stiffness of the connection portion is improved, the bending stress is reduced, the wall thickness of the key portion in the middle of the keel node is increased, the strength is optimized, and greater local stress can be borne.

[0065] The mounting seat 100 of the keel node protection device is sleeved outside the smooth transition section 420 of the keel node, the elastic body 300 is used to weaken the mechanical transmission caused by the relative displacement between the rigid structures, so as to achieve the purpose of protecting the keel node from being damaged.

[0066] In some embodiments of the present invention, the keel node can be made of steel or titanium alloy, the keel node can be integrally forged, or the connection between the top conical section 410, the smooth transition section 420, and the bottom conical section 430 of the keel node can be connected by welding.

[0067] An embodiment of the present invention also provides a top-tensioned riser, which includes multiple individual production risers and the aforementioned keel node assembly, wherein the keel node assembly is disposed between two adjacent individual production risers.

[0068] Because it has the keel node components described above, it has the same advantages as described above.

[0069] An embodiment of the present invention also provides an oil production platform, including a platform body and the aforementioned top-tensioned riser. The top of the top-tensioned riser extends above the platform body through the keel of the platform body and is connected to the platform body via a tension system. When the top-tensioned riser is connected to the platform body, the keel nodes of the platform body and the top-tensioned riser are positioned opposite each other. That is, when the platform body and the top-tensioned riser move relative to each other, the keel of the platform body can only contact the keel node.

[0070] Because the oil production platform includes a top-tensioned riser with the aforementioned keel node assembly, it has the same advantages as described above.

[0071] Embodiments of the present invention also provide a keel node component design method, which is used to design the keel node component as described above, and the design method includes the following steps:

[0072] Step S100: Predict the maximum offset between the platform body and the top-tensioned riser based on the motion characteristics and environmental parameters of the platform body. Based on the maximum offset Determine the maximum stress between the two. And preset a safety factor .

[0073] Specifically, researchers can predict the maximum offset between the platform body and the top-tensioned riser based on the platform's motion characteristics and environmental parameters. For example, the maximum offset between the platform body and the top-tensioned riser can be predicted based on the motion characteristics of the dry tree cylindrical platform and the environmental parameters of the sea area. Then based on the maximum offset The maximum stress between the platform body and the top-tensioned riser can be calculated. Based on experience, experimental values ​​for the preset safety factor are given. .

[0074] Step S200, based on maximum stress and the safety factor , the effective pressure bearing area of the elastic body 300 is determined as , satisfies , is the average compressive stress limit of the support 200 in the working period.

[0075] Specifically, based on the maximum stress and the safety factor , the effective pressure bearing area of the elastic body 300 can be calculated according to the formula to determine an experimental value from the range. Wherein, is the average compressive stress limit of the support 200 in the working period.

[0076] Step S300, the shear deformation caused by external compression is , the total thickness of the elastic gasket 320 is determined as , satisfies .

[0077] Specifically, the experimental personnel can select an experimental value of the shear deformation caused by external compression , and according to the experimental value , the total thickness of the elastic gasket 320 of the elastic body 300 is determined as in the range, satisfies , and the experimental value of the total thickness of the elastic gasket 320 is selected from the range as .

[0078] Step S400, based on the total thickness of the elastic gasket 320 , the side length or the diameter of the support 200 is determined, when the cross section of the support 200 is rectangular, the side length of the support 200 satisfies , when the cross section of the support 200 is circular, the diameter of the support 200 satisfies .

[0079] Specifically, this step determines the side length or the diameter of the cross section of the support 200 based on the total thickness of the elastic gasket 320 .

[0080] The cross section of the support 200 can be square, at this time, the side length of the support 200 needs to satisfy ​, the experimenter can determine an experimental value of the cross-sectional side length of the support 200 from the range .

[0081] Alternatively, the cross-section of the support 200 can also be circular, in which case, the diameter of the support 200 needs to satisfy , the experimenter can determine an experimental value of the cross-sectional diameter of the support 200 from the range .

[0082] Step S500, based on the maximum stress , the safety factor a and the effective pressure-bearing area of the elastic body 300 , determine the thickness of the single-piece metal plate 310 , the thickness of the elastic gasket 320 located on the upper layer of the metal plate 310 and the thickness of the elastic gasket 320 located on the lower layer of the metal plate 310 , wherein the thickness of the single-piece metal plate 310 , the thickness of the elastic gasket 320 located on the upper layer of the metal plate 310 , the thickness of the elastic gasket 320 located on the lower layer of the metal plate 310 , and .

[0083] Specifically, based on the maximum stress , the safety factor a and the effective pressure-bearing area of the elastic body 300 , the thickness of the single-piece metal plate 310 , the thickness of the elastic gasket 320 located on the upper layer of the metal plate 310 and the thickness of the elastic gasket 320 located on the lower layer of the metal plate 310 are given. Wherein the thickness of the single-piece metal plate 310 , the thickness of the elastic gasket 320 located on the upper layer of the metal plate 310 , the thickness of the elastic gasket 320 located on the lower layer of the metal plate 310 , and . The experimenter can determine an experimental value of the thickness of the single-piece metal plate 310 from the above range as , an experimental value of the thickness of the elastic gasket 320 located on the upper layer of the metal plate 310 as and an experimental value of the thickness of the elastic gasket 320 located on the lower layer of the metal plate 310 as .

[0084] Step S600, obtain the inner diameter and outer diameter of the production riser joint of the top-tensioned riser And based on the inner diameter of a single riser pipe. and outer diameter Determine the inner diameter of the keel node. Outer diameter of the connection between the keel node and a single production riser pipe Based on the effective offset distance of the keel of the oil production platform Determine the length of the smooth transition section 420 at the keel node. ,in, , , .

[0085] Specifically, this step is used to calculate the dimensions of the keel joints. First, the inner diameter of a single vertical riser for the top-tensioned type is obtained. and outer diameter Determine the inner diameter of the keel node. Outer diameter of the connection between the keel node and a single production riser pipe Then, based on the effective cheap distance of the oil production platform's keel... The length range of the smooth transition segment 420 of the keel node is obtained. And from this range, an experimental value for the length of a smooth transition segment 420 was determined. .

[0086] It should be noted that, The purpose is to ensure that when the platform body rises and falls with the waves, the keel can only contact the smooth transition section 420 of the keel node, and will not contact other positions of the keel node.

[0087] Step S700: Obtain the inner diameter of the keel of the platform body. And the length of the support 200 is preset to be The inner diameter of the keel based on the main body of the platform. The total thickness of the elastic gasket is 320. Thickness of a single metal plate 310 The length of the support is 200. Determine the outer diameter of the smooth transition section 420 of the keel node. The smooth transition section of the keel node has an outer diameter of 420. satisfy .

[0088] Specifically, this step is used to determine the outer diameter of the smooth transition section 420 of the keel node. First, obtain the inner diameter of the keel of the platform's main body. And the length of the support 200 is preset to be The inner diameter of the keel based on the main body of the platform. The total thickness of the elastic gasket is 320. Thickness of a single metal plate 310 and the length of the support 200 determining the range of the outer diameter of the smooth transition section 420 of the keel node and determining the experimental value of the outer diameter of the smooth transition section 420 of the keel node in the range as .

[0089] Step S800, determining the curvature of the connection between the keel node and the production riser joint based on the outer diameter of the connection between the keel node and the production riser joint and the outer diameter of the smooth transition section 420 of the keel node , the curvature of the connection between the keel node and the production riser joint and the curvature of the end of the smooth transition section 420 of the keel node , the curvature of the connection between the keel node and the production riser joint and the curvature of the end of the smooth transition section 420 of the keel node satisfy .

[0090] Specifically, this step is used to determine the outer diameter of the connection between the keel node and the production riser joint and the curvature of the end of the smooth transition section 420 of the keel node . The end of the keel node and the production riser joint are connected through a rounded transition, and the top tapered section 410 and the smooth transition section 420 of the keel node, and the bottom tapered section 430 and the smooth transition section 420 are also connected through a rounded transition. The curvature of the connection between the keel node and the production riser joint and the curvature of the end of the smooth transition section 420 of the keel node satisfy .

[0091] Step S900, checking whether the keel node is damaged when the oil production platform rises and falls with the waves, deviates and rotates to produce the maximum stress peak value, if the keel node is damaged, the design parameters are replaced and the above steps are repeated until the keel node is no longer damaged.

[0092] Specifically, this step is used to verify the selection of the above experimental value. The software is used to simulate whether the keel node is damaged when the oil production platform rises and falls with the waves, deviates and rotates to produce the maximum stress peak value under the above design parameters, i.e., the above experimental value. If the keel node is damaged, the above experimental value is replaced and the steps S100~S800 are repeated again until the keel node is no longer damaged.

[0093] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A keel node assembly design method, characterized by, The keel node assembly comprises: a keel node, which comprises a top tapered section (410), a smooth transition section (420) and a bottom tapered section (430) in sequence from top to bottom; a keel node protection device, comprising a mounting seat (100), a plurality of supports (200) and a plurality of elastic bodies (300), the mounting seat (100) is used for sleeving the outside of the smooth transition section (420) of the keel node, a plurality of supports (200) are distributed along the circumference of the mounting seat (100), and a plurality of elastic bodies (300) are arranged one by one at one end of the plurality of supports (200) away from the mounting seat (100), and the elastic body (300) is formed by alternately stacking a metal plate (310) and an elastic gasket (320); The design method comprises: predicting a maximum offset between the platform body and the top-tensioned riser based on motion characteristics of the platform body and environmental parameters determining a maximum stress therebetween based on the maximum offset and a safety factor is preset ; based on the maximum stress and the safety factor , the effective bearing area of the elastomer (300) is determined as , satisfies , is the average stress limit of the support (200) during operation. The preset external compression causes a shear deformation of , the total thickness of the elastic gasket (320) is determined as , satisfies ; based on the total thickness of the elastic gasket (320) , determine the side length of the support (200) or the diameter , when the cross section of the support (200) is rectangular, the side length of the support (200) satisfies , when the cross section of the support (200) is circular, the diameter of the support (200) satisfies ; based on the maximum stress , the safety factor a and the effective bearing area of the elastomer (300) , determining the thickness of the single sheet metal plate (310) , the thickness of the elastomeric gasket (320) located on the upper layer of the metal plate (310) and the thickness of the elastomeric gasket (320) located on the lower layer of the metal plate (310) wherein the thickness of the single sheet metal plate (310) , the thickness of the elastomeric gasket (320) located on the upper layer of the metal plate (310) , the thickness of the elastomeric gasket (320) located on the lower layer of the metal plate (310) , and ; Obtain the inner diameter of a single production riser for a top-tensioned riser. and outer diameter Effective offset distance of the keel of the oil production platform And based on the inner diameter of the single production riser. and outer diameter Determine the inner diameter of the keel node. The outer diameter of the connection point between the keel node and the single production riser pipe Based on the effective offset distance of the keel of the oil production platform Determine the length of the smooth transition segment (420) of the keel node. ,in, , , ; An inner diameter of a keel of a platform body is acquired , and a length of the support (200) is preset , based on the inner diameter of the keel of the platform body , a total thickness of the elastic gasket (320) , a thickness of a single piece of the metal plate (310) and the length of the support (200) , an outer diameter of a smooth transition section (420) of the keel joint is determined , the outer diameter of the smooth transition section (420) of the keel joint satisfies ;​ an outer diameter of the connection of the keel node to the production riser joint and an outer diameter of the smooth transition section (420) of the keel node a curvature of the connection of the keel node to the production riser joint and a curvature of the end of the smooth transition section (420) of the keel node a curvature of the connection of the keel node to the production riser joint and a curvature of the end of the smooth transition section (420) of the keel node satisfies ; checking whether the keel node is damaged when the maximum stress peak value of the oil production platform is generated by wave lifting, deviation and rotation, if the keel node is damaged, the design parameters are replaced and the above steps are repeated until the keel node is no longer damaged.

Images