Support for riser and method for coupling and uncoupling

Abstract

The invention relates to a system for supporting the tensile load of a riser, the component having the basic function of supporting the riser, in which the mechanism for supporting the riser is an integral part of the upper cone, thus eliminating the need to install a wedge by shallow diving and also avoiding that the locking mechanism is an integral part of the riser top termination (L). There are a minimum number of movable components, which improves the maintainability of the system. Furthermore, if maintenance is required, the size and weight of the components are compatible with diving operations. For the pull-in operation, it is provided that the wedge returns to its working position only under the action of gravity. In the case of pull-out, the concept of an automatic wedge retraction mechanism has been proposed. The invention also proposes a new geometry of the riser top termination (TTR) (L) aimed at simplifying the riser top termination, in which the locking mechanism is considered an integral part of the upper cone of the support tube, also eliminating the movable components in order to stabilize the lateral movement of the locking mechanism (function previously performed by the locking ring or compensation gap).

Description

Technical Field

[0001] This invention relates to rigid or flexible riser interconnect components for support pipes and riser top terminals with improved geometry, used in the oil extraction / exploration field, primarily in floating production and storage units (FPSOs), which have the primary function of supporting rigid risers. Background Technology

[0002] The possibility of serial manufacturing of FPSO hulls for subsalt poles (replicas) underscores the need to adapt support systems for risers and production facilities currently designed to future realities. The generalization of structures and operating environments allows for the manufacture of stationary production units (SPUs) even before the bottom layout of the production site is fully defined, leading to the development of a type of support pipe known as the multi-functional bellows (MFBM).

[0003] Regarding the type of riser, it should be noted that flexible risers are manufactured using interlocking steel profiles with interlocking layers of elastic material, which provides relative flexibility to the riser compared to those structures that use rigid metal pipes in their manufacture.

[0004] Meanwhile, rigid risers are manufactured from rigid steel pipes and exhibit a free-cable structure in the interconnection between the production line and the stationary production unit (SPU). These risers can be directly supported on float-supported risers (BSRs) known as steel catenary risers (SCRs) or SCR-type risers, which use carbon steel pipes with an internally coated corrosion-resistant metal liner.

[0005] The basic concept established for this new type of riser support is that it should be versatile enough to allow the use of flexible or rigid risers with some variation in their internal diameter, and to be interconnected via either the port or starboard side. The interface between the MFBM and the top end of the riser depends on the technology used (rigid or flexible riser), where the rigid riser is locked from the top, and the flexible riser is locked from the bottom.

[0006] When the flexible riser is supported, the locking of the bending reinforcement is performed in the same manner as the bell mouth of the BSN300 series (US005947642A), wherein the bending reinforcement cap is locked by a pawl and the riser tension is anchored by a suspension on the upper platform of the FPSO.

[0007] In the case of rigid riser supports, a novel concept for a riser top terminal (TTR) has been proposed. The riser top terminal has been named in several different ways, such as the "Hang-off adapter" used in the Cidade Ilhabela FPSO, or "Shank" by the applicant during the design of the multi-functional bell mouth. In this concept, the riser terminal includes a flexible joint or stress joint in its lower portion, and the riser tension is anchored in the upper cone of the MFBM. This force is transmitted by a sliding element, which, in the initial development phase of the MFBM concept, will be installed via shallow diving.

[0008] The applicant's first experience with supporting rigid risers in a multi-functional bell mouth occurred on the interconnection of the Cidadede Ilhabela FPSO. Although this SPU did not have a multi-functional bell mouth, it used a support pipe with the same profile as the MFBM.

[0009] During the detailed design of the suspension adapter for the Cidade de Ilhabela FPSO, some complexities were observed, but these complexities were not identified during the conceptualization phase of the MFBM development. The primary obstacle to modifying the invention was the discovery that, for safety reasons, divers could not install the sliding element, as their hands would be placed between the MFBM and the riser subjected to stress from the pull-in cable; this was considered an unacceptable risk.

[0010] The solution found for this problem was a hinged sliding element (SBM-WO2017 / 034409A1) developed by the charterer of the Cidade de Ilhabela FPSO. However, this solution cannot be effectively applied to replica FPSOs because, in addition to being protected by the SBM patent, the device has dimensions that are mismatched with the replica riser support platform, which has very limited space for installing the MFBM.

[0011] Another key point observed during the interconnection of the rigid riser with the Cidade de Ilhabela FPSO is the compensator gap system corresponding to the "locking ring" in the original MFBM concept: although this compensator gap system can laterally lock the suspension adapter, thus allowing the transmission of shear forces from the riser, it cannot guarantee complete suppression of riser installation misalignment.

[0012] By analyzing all the limitations observed during the detailed design of the suspension adapter for the Cidade de Ilhabela FPSO, the applicant developed a new terminal concept. For this purpose, the support slide is conceived as an integral component of the suspension adapter (HOA-BR), thus avoiding the need for submersion to install the slide. A lower locking slide system, replacing the "locking ring" in the initial concept, is also planned.

[0013] Although considered a viable solution, the HOA-BR concept was terminated due to its numerous moving parts and the need for extensive detailed engineering, such as defining the hydraulic system used to drive the upper sliding member. Based on the above disclosure, it was determined that the design of the support tube assembly needed to be adjusted to better facilitate the pulling-in operation of the rigid riser.

[0014] Document PI0902469B1 discloses a multi-angle support system for connecting risers to the side of an oil production unit. This system includes at least one support member capable of securing the riser to the side of a stationary production unit (SPU) at a defined angle of arrival, and more specifically, to the side of the stationary production unit in an FPSO. It also provides the possibility of alternative combinations of arrangement structures, allowing flexible or rigid risers to have a wide variety of angles of arrival in any configuration that may occur during the SPU's service life. This document differs from the present invention in that it does not show significant changes to the support pipe and does not disclose geometric modifications in the riser top terminal that could simplify equipment.

[0015] Document SG10201601701A1 discloses an apparatus for connecting risers to oil outlet lines, particularly when connecting to the side or tower of a floating storage or production vessel (FPSO). Specifically, the invention relates to a bell mouth that can be used for various types of risers. The document makes no mention of geometric modifications to the top end of the riser, nor of a rigid riser support mechanism that is an integral part of the upper cone.

[0016] Document WO2017034409A1 discloses an upper locking system for supporting the riser of a floating platform (FPSO). The riser is inserted into a support tube and mounted on a suspended support tube. The upper locking system includes a plurality of hinged slides, each of which is arranged to be rotatably movable from an open position to a closed position. The hinged slides are located at the top end of the riser; however, in this invention, the hinged slide is an integral part of the upper cone of the flared mouth, thereby eliminating the need for installing the slides via shallow diving.

[0017] The present invention relates to a rigid riser support with different features that offer advantages over features disclosed in prior art documents. Summary of the Invention

[0018] This invention relates to a riser interconnection component for use in a support pipe type device, which focuses on the replacement / innovation of the upper portion and has the primary function of supporting rigid risers. Although the invention is intended for supporting rigid risers, the component can also be readily adapted to support flexible risers, and the invention is also adaptable to any support pipe type device.

[0019] Unlike the initial concept of the MFBM-type riser support system, the approach here assumes that the rigid riser support mechanism is an integral part of the upper cone. Therefore, it eliminates the need for shallow diving to install the sliding element and avoids ensuring the locking mechanism is an integral part of the riser top terminal (TTR). Another key point is the minimal number of moving parts, which improves system maintainability. Furthermore, if maintenance is required, the size and weight of the components are well-suited for diving operations.

[0020] For the pull-in operation, the slider is expected to return to its working position solely under the influence of gravity. Furthermore, all mechanism components are matched to the expected contact force during cable pull-in.

[0021] In the pull-out operation, an automatic slider retraction mechanism was developed. This concept is based on a mechanism link that interconnects all the sliders of the upper cone, giving the assembled mechanism only one degree of freedom: the common retraction of all sliders. It should be emphasized that there is no obstacle to using this automatic retraction mechanism in the pull-in operation as well.

[0022] It should be further emphasized that the automatic retraction mechanism of the slider can be used as an alternative to gravity. This mechanism can be employed to ensure that the slider moves to the intended position—retracted or extended—during the pull-in operation if any effects are found that cast doubt on the demonstrated functionality (e.g., corrosion or growth of marine organisms).

[0023] A new riser top terminal (TTR) geometry is also proposed, which aims to simplify the riser top terminal, wherein, in addition to treating the locking mechanism as an integral part of the upper cone of the support pipe type device, the moving parts for stabilizing the lateral movement of the locking mechanism (a function previously performed by the locking ring or clearance compensator) are eliminated.

[0024] Purpose of the invention

[0025] The purpose of this invention is to support the riser.

[0026] The purpose of this invention is to eliminate the need to install sliding components by shallow diving.

[0027] The purpose of this invention is to provide a new riser top terminal (TTR) geometry designed to simplify riser top terminals.

[0028] The purpose of this invention is to prevent the locking mechanism from becoming an integral part of the TTR.

[0029] The purpose of this invention is to reduce the number of moving parts to improve system maintainability.

[0030] The purpose of this invention is to ensure that the size and weight of the components are compatible with diving operations.

[0031] These and other objectives, such as flexible riser supports, will be achieved through the objectives of this invention. Attached Figure Description

[0032] The invention will now be described in more detail with reference to the accompanying drawings, which illustrate examples of the invention in a schematic manner and without limiting the scope of the invention. In the drawings, the following are present:

[0033] - Figure 1 The diagram shows a schematic representation of the upper vertebral body and the rigid riser support components;

[0034] - Figure 2 The diagram shows a cross-sectional view of the upper vertebral body;

[0035] - Figure 3 The illustration shows details of the sliding groove used as an auxiliary guide.

[0036] - Figure 4 The illustration shows details of the shaft (1), fork (2) and slider (3) assembly, as well as the chamfer on the shaft;

[0037] - Figure 5 The illustration shows details of the engagement pin used for the connection between the shaft, fork, and slider.

[0038] - Figure 6 The diagram illustrates the automatic retraction mechanism of the slider;

[0039] - Figure 7 The diagram illustrates the automatic retraction mechanism of the slider;

[0040] - Figure 8 The geometry of the TTR is illustrated.

[0041] - Figure 9 The diagram illustrates the geometry of a TTR suitable for supporting a flexible riser.

[0042] - Figure 10 The diagram illustrates the start of the upward movement of the slider / fork / axis assembly;

[0043] - Figure 11 The diagram illustrates the end of the downward movement of the slider / fork / axis assembly;

[0044] - Figure 12 The illustration shows the TTR losing contact with the slider after being pulled;

[0045] - Figure 13 The illustration shows the complete retraction of the slider and the subsequent removal of the TTR;

[0046] - Figure 14 The diagram illustrates the automatic retraction mechanism of the slider. Detailed Implementation

[0047] Rigid riser supports have the following components:

[0048] • Axis (1);

[0049] ·Fork(2);

[0050] • Slider (3);

[0051] • Wear-resistant bushing (4);

[0052] • Support components for the camera (5);

[0053] • Conical aperture (6);

[0054] • Anti-fouling pin (7);

[0055] ·Connecting pin (8);

[0056] • Track (9);

[0057] • Pin (10) used for retracting the lever;

[0058] • Fixture (11);

[0059] • Alternatively, a slider retraction mechanism rod (12), a shaft extension (14), and a slider retraction tool (15) may be present, which are installed for the pull-out step (or, if necessary, for the pull-in step).

[0060] • Hole (13) for the tool of the sliding component retraction mechanism;

[0061] • Spare eyelet (16) for sliding retraction.

[0062] The shaft (1) is the component that primarily guides the retraction and extension of the slider (3) during the pull-in / pull-out operation. When observing the geometry of the shaft, note that the thickest part of the shaft defines the end position of the stroke. An eyelet (16) is added in this thicker area to serve as a pull point for retracting the slider (3). The grooves on the shaft, which are easily visible through a camera mounted on the support (5) or ROV, indicate full retraction of the slider (3) to release the TTR (L) during the pull-out operation.

[0063] The slider (3) is an effective component for supporting the tensile load of the rigid riser. During the pull-in operation, there is contact between the pull-in cable and the slider (3), and the slider (3) retracts without resistance. To avoid damage to the pull-in cable or the slider (3) itself in this contact, the surface facing the axial direction of the system is circular / streamlined.

[0064] To avoid generating lateral loads, the rail (9) acts as an auxiliary guide during contact with the pull-in cable, because the rail interacts with the sliding groove ( Figure 3 Together, they serve as a reaction surface for lateral loads, thereby preventing shaft (1) warping and the resulting system lock-up.

[0065] The fork (2), which is the only necessary item for installing the retraction tool, is located between the shaft (1) and the slider (3), and the fork (2) has holes for installing the retraction tool (pin 10 and rod 12) for the joint retraction of the slider (3).

[0066] The connecting pin (8) is the component responsible for connecting the shaft (1), the sliding member (3), and the fork (2).

[0067] The cone eyelet (6) is a component used to lift the upper cone (k).

[0068] The anti-fouling pin (7) is a component used to prevent fouling in the holes of the fork, and the retractable tool pin (10) and the corresponding clamp (11) will enter the holes.

[0069] The wear-resistant bushing (4) is a component used to reduce wear on the upper cone (k). During the installation of the rigid riser, the pull-in cable will come into contact with the upper cone (k), which may cause damage to the upper cone (k). The wear-resistant bushing (4) is a component whose geometry presents itself as a priority point for contact with the pull-in cable, and whose wear is foreseeable in the design and will not affect the structural strength and function of the mechanism.

[0070] The spare eyelet (16) for sliding retraction is an eyelet of the shaft (1), which can be used for shaft movement in the event of a failure of the main unlocking system, and the sliding retraction tool (15) is connected to the sliding retraction mechanism eyelet (13), which is in turn connected to the shaft extender (14).

[0071] To simplify, a new geometry was developed for TTR(L), such as that that can be... Figure 8 As observed, this geometry, besides treating the locking mechanism as an integral part of the upper cone (k) of the support tube, also eliminates moving parts to stabilize the lateral movement of the locking mechanism. The new configuration includes the following regions:

[0072] • Riser pre-alignment profile (a);

[0073] • Sliding element support area (b);

[0074] • Spherical geometry (c) used for the initial entry of TTR(L);

[0075] • Hourglass shape (d) used to minimize pull-in force;

[0076] • Tapered surface (e) used for gap suppression and final alignment;

[0077] • Cylindrical surface (f) used to transfer shear force to the support tube;

[0078] • Rigid transition devices (g) between riser and TTR(L), such as flexible joints (illustrative examples in the attached figures), stress joints, etc.;

[0079] • Riser extension (h) connected to the flexible joint.

[0080] The above area describes the TTR(L) solution for rigid riser supports. For example, it can be found... Figure 9 As observed, the TTR(L) can be easily adapted to support a flexible riser by replacing components (g) and (h) with a bending stiffener (i), which is a component commonly used to provide protection for flexible risers.

[0081] The riser pre-alignment profile (a) is the transition area of ​​the TTR (L) between the small-diameter flange of the pull head used for riser pull-in and the sliding support area (b). This transition area is necessary for smooth riser pre-alignment in the support tube, thereby eliminating the risk of overload in the pull-in system.

[0082] The sliding support area (b) contains a surface that effectively supports the tensile load on the riser, and this surface presents an angle that matches the sliding member (3) of the upper cone (k). The basic premise is that, regardless of the demand from the riser, the contact pressure between the TTR (L) and the sliding member (3) of the upper cone (k) can be reduced, but not suppressed to the point that the contact between the top end (L) of the riser and its support system stops.

[0083] Although the first contact area between the TTR (L) and the support pipe is exactly at the edge of the sliding support area (b), the spherical geometry (c) for the entry of the TTR (L) has a large diameter, thus the spherical geometry is the primary surface for the initial contact between the riser top end (L) and the support. Because the spherical geometry is spherical, the contact conditions between the TTR (L) and the support pipe are fairly uniform regardless of any misalignment during installation, thus the spherical geometry acts as a "spherical joint" for the initial entry of the riser.

[0084] The hourglass-shaped region (d) allows for misaligned insertion of the TTR (L) almost along its entire length, thus allowing the spherical region (c) to effectively function as a spherical joint, thereby avoiding significant resistance during the pull-in operation. The hourglass-shaped region (d) is located below the spherical region (c), and within this region (d) lies a portion of the TTR (L) whose diameter is significantly smaller than the inner diameter of the support tube.

[0085] After the TTR(L) has almost completely entered the support tube, the gap provided by the hourglass region (d) needs to be suppressed in the region called the conical surface (e) for gap suppression, so that the support region of the TTR(L) is aligned with the support slide (3) of the upper cone (k) and promotes effective alignment between the TTR(L) and the support tube.

[0086] The cylindrical surface (f) used to transmit shear force is the final element in contact between the TTR (L) and the support tube, thus ending the pull-in operation. This combination of manufacturing requirements, due to the tight tolerances of the spherical geometry (c) and the cylindrical surface (f) relative to the inner diameter of the support tube, establishes a high degree of self-alignment capability for the TTR (L). A significant advantage of the tight tolerances of this cylindrical surface is that it eliminates the need for movable parts used to suppress clearance and transmit shear force from the riser.

[0087] The connection (pull-in) method begins with the TTR(L) entering the support tube, where the TTR(L) is pre-aligned. Then, the spherical geometry (c) of the TTR(L) begins to contact, generating the first resistance torque for the TTR(L) to enter the support tube. From there, it can be noted that the tapered surface of the TTR(L) contacts the support tube to eliminate the gap between the TTR(L) and the support tube, and consequently, to align and center the TTR(L) within the support tube. With the TTR(L) already centered in the support tube, the TTR(L) approaches and contacts the slider (3). The TTR(L) begins to contact the slider (3) and pushes the TTR(L) upward together with the slider (3) / fork (2) / shaft (1) assembly. After the upward movement of the slider (3) / fork (2) / shaft (1) assembly ends, the slider (3), having lost contact with the TTR(L), descends due to gravitational acceleration, and the slider (3) moves downward. After completing the downward movement, TTR(L) descends and is fully supported by the slider (3).

[0088] Alternatively, the retraction mechanism (12) of the slider (3) can be used for the final pull-in step described in the previous paragraph. That is, the step of contacting the TTR (L) on the slider (3) is replaced by the prior retraction of the slider (3) using the retraction mechanism (12). After the upward movement of the TTR (L) ends, the retraction tool (15) is activated in the opposite direction to extend the slider (3) and allow the TTR (L) to be finally in place.

[0089] For the disconnection (pull-out) method, it is necessary to install an automatic slider retraction mechanism (3). The main components of this automatic slider retraction mechanism are: slider retraction mechanism rod (12), shaft extender (14), and slider retraction tool (15), as shown in Figure 6 , Figure 7 , Figure 13 This can be observed. After installing the automatic retraction mechanism, it is necessary to increase the TTR(L) to [the specified value]. Figure 12 The over-pull position in the middle causes the TTR(L) to no longer rest on the slider (3). The next step is to apply the retraction tool (15) of the slider (3) to the shaft extender (14), causing the shaft (1) / slider (3) / fork (2) assembly to which the extender (14) is attached to begin to retract. With this movement, all the retraction levers (12) of the slider begin to move due to kinematic constraints, thereby causing the other slider (3) / fork (2) / shaft (1) assemblies to retract. Then, as Figure 13 This can reduce TTR(L) and remove it from the upper cone (k).

[0090] It should be noted that although the invention has been described with reference to the accompanying drawings, the invention can be modified and adjusted by those skilled in the art according to specific circumstances, provided that such modifications and adjustments are within the scope of the invention as defined herein.

Claims

1. A support member for a riser pipe, characterized in that, The support member includes: - A riser interconnection component, the riser interconnection component being located in at least one pipe support member, the riser interconnection component including a rigid riser support mechanism, and the rigid riser support mechanism being an integral part of the upper cone (k); - A geometrically improved riser top end (L) where moving parts are eliminated. The upper cone (k) of the support tube includes a shaft (1), a fork (2), a slider (3), a wear-resistant bushing (4), a support for the camera (5), a cone eye (6), a dirt-proof pin (7), a connecting pin (8), a track (9), a pin for retracting the rod (10), a clamp (11), an eye for the slider retraction mechanism tool (13), and a spare eye for slider retraction (16). The riser top terminal (L) includes a riser pre-alignment profile (a), a sliding support area (b), a spherical geometric region for initial entry of the riser top terminal (L) (c), an hourglass-shaped region for minimizing pull-in force (d), a conical surface for gap suppression and final alignment (e), a cylindrical surface for transmitting shear force to the support pipe (f), and a rigid transition device (g) between the riser extension and the riser top terminal (L).

2. The support member for a riser according to claim 1, characterized in that, The support includes a bending reinforcement (i) that replaces the rigid transition device (g) and the riser extension (h) to support the flexible riser.

3. The support member for a riser according to claim 1, characterized in that, The shaft (1) has a groove that indicates the full retraction of the slider (3).

4. The support member for a riser according to claim 1, characterized in that, The support includes a slider retraction mechanism rod (12), a shaft extender (14), and a tool (15) mounted for retracting the slider.

5. The support member for a riser according to claim 1, characterized in that, The slider (3) is circular / streamlined on the surface that contacts the pulled-in cable.

6. The support member for a riser according to claim 1, characterized in that, The fork (2) has a hole for mounting the retraction tool.

7. The support member for a riser according to claim 6, characterized in that, The retraction tool includes a pin (10) for retracting the lever and a sliding retraction mechanism lever (12).

8. The support member for a riser according to claim 1, characterized in that, The engagement pin (8) connects the shaft (1), the slider (3), and the fork (2).

9. The support member for a riser according to claim 5, characterized in that, The wear-resistant bushing (4) is the preferred point of contact with the pulled-in cable and reduces wear on the upper cone (k).

10. The support member for a riser according to claim 1, characterized in that, The riser pre-alignment profile (a) eliminates the risk of overload in the pull-in system and ensures smooth alignment of the riser in the support tube.

11. The support member for a riser according to claim 1, characterized in that, The sliding support area (b) includes a surface that effectively supports the tensile load of the riser, and the surface that effectively supports the tensile load of the riser presents an angle that matches the sliding member (3) of the upper cone (k).

12. The support member for a riser according to claim 1, characterized in that, The spherical geometry region (c) for entry of the riser top terminal (L) exhibits a spherical geometry with a larger diameter than the sliding support region (b), and the spherical geometry region (c) is the primary surface for initial contact between the riser top terminal (L) and the support.

13. The support member for a riser according to claim 1, characterized in that, The spherical geometry region (c) for entry into the top terminal (L) of the riser ultimately serves as a spherical connector for the initial entry into the riser.

14. The support member for a riser according to claim 1, characterized in that, The hourglass-shaped region (d) is located below the spherical geometry region (c) and allows for misaligned insertion of the riser top terminal (L).

15. The support member for a riser according to claim 1, characterized in that, After the top end (L) of the riser enters the support tube, the tapered surface (e) for gap suppression suppresses the gap provided by the hourglass region (d) and aligns the top end (L) of the riser with the support tube.

16. The support member for a riser according to claim 1, characterized in that, The cylindrical surface (f) for transmitting shear force is located below the tapered surface (e) for gap suppression and is the last element to contact the tube support.

17. A connection method using a support member for a riser according to any one of claims 1 to 16, characterized in that, The connection method includes the following steps: - Insert the top end (L) of the riser into the support pipe in an upward manner; - Make the support tube contact the spherical geometry region of the top end (L) of the riser and generate a first torque to resist entry; - Make the tapered surface of the top end (L) of the riser begin to contact the support pipe; - Position the top end (L) of the riser at the center of the support pipe; - Make the slider (3) contact the top end (L) of the riser and push the top end of the riser upward together with the slider (3) / fork (2) / shaft (1) assembly; - The upward movement of the sliding member (3) / fork (2) / shaft (1) assembly ends, and the assembly is lowered by gravity after the contact with the top end (L) of the riser ends; - To end the downward movement of the slider (3) / fork (2) / shaft (1) assembly; - Lower the top end (L) of the riser completely and place the top end (L) of the riser on the slider (3).

18. A method for disconnecting a connection using a support member for a riser according to any one of claims 1 to 16, characterized in that, The method comprises the following steps: - Install a slider retraction mechanism, which includes: a slider retraction mechanism rod (12), a shaft extender (14), and a slider retraction tool (15). - Raise the top end (L) of the riser to the over-pull position; - The slider retraction tool (15) is used to retract the slider (3) / fork (2) / shaft (1) assembly by acting on the shaft extender (14); - Lower the riser top terminal (L) and remove the riser top terminal (L).

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