Cone with a pivoting mechanism for supporting a hang-off adapter in diverless operations

Abstract

The present utility model relates to a cone with a pivoting mechanism for supporting a hang-off adapter (HOA) in diverless operations, comprising: an upper cone configured to transmit the vertical load of the HOA to a support pipe; wedges mounted in the upper cone, configured to support the vertical load of the HOA and to centralise its position in the upper cone; hydraulic cylinders connected to the wedges, configured to move the wedges between an open position and a closed position, enabling pull-in and pull-out operations on the riser; springs associated with the hydraulic cylinders, configured to return the wedges to the closed position when the hydraulic cylinders are depressurised; pivoting rods connected to the hydraulic cylinders and to the wedges, configured to transmit the movement of the hydraulic cylinders to the wedges; and a wedge holder ring fixed in the upper cone, configured to support the pivoting rods and the hydraulic cylinder and spring assemblies.

Description

[0001] CONE WITH PIVOTING MECHANISM FOR HANG-OFF ADAPTER SUPPORT IN DIVERLESS OPERATIONS UTILITY MODEL FIELD

[0001] This Utility Model falls within the technical field of rigid riser supports for offshore operations, specifically in the area of ​​automated mechanisms for supporting and handling risers on floating production platforms and other subsea installations.

[0002] More specifically, the Utility Model refers to a support mechanism for rigid risers used in offshore operations. This mechanism includes automated pivoting wedges, operated by hydraulic cylinders, which eliminate the need for shallow dives, increase the reliability of pull-in and pull-out operations, and reduce complexity and maintenance needs. BACKGROUND OF THE UTILITY MODEL

[0003] Currently, the upper locking system of the Diverless Unified Support Tube (TSUDL) employs a wedge retraction mechanism consisting of a cam-carrying crown, rods with rollers guided by rails, and a drive spindle. This system allows for remote movement of the wedges during pull-in and pull-out activities, and can be operated by remotely operated vehicles (ROVs), eliminating the need for divers (diverless).

[0004] In addition to complexity and maintenance, the space required by the current system may limit its applicability in new floating production, storage and offloading (FPSO) units that demand compact and efficient solutions.

[0005] Thus, there is a clear need for a simplified system, less sensitive to the growth of marine life, that reduces manufacturing and maintenance complexity, and that is compatible with the geometry of current riser support systems. STATE OF THE ART

[0006] US patent document US2011280668A1 presents a system for suspending risers on floating platforms used in drilling, completion, production, or maintenance operations of oil and / or gas wells. The main element of this invention is the suspension adapter, designed to support the weight of the riser while allowing its relative rotation with respect to the floating platform. However, although US patent document US2011280668A1 also describes a system for supporting risers in offshore operations, including support and handling mechanisms for rigid risers, it fails to describe a device capable of reducing the space required for installation and minimizing interference with adjacent structures, in addition to the use of pivoting wedges, as in the present Utility Model.

[0007] Document WO2013059122A1 presents a hang-off assembly designed to support the riser string after its disconnection from sensitive equipment on the drilling platform. This hang-off assembly is essential to facilitate the movement of the drilling platform without the need to disassemble the entire riser string, thus avoiding damage to the equipment. Although it describes a hang-off assembly, as described in this Utility Model, document WO2013059122A1 does not propose the use of a system with pivoting wedge mechanisms.

[0008] Document BR102021017344A2 presents the Diverless Unified Support Tube (TSUDL), which can be divided into three main components: the upper cone, responsible for supporting the rigid riser; the guide tube, which integrates with the FPSO riser balcony; and a centralizer, which centers the hang-off adapter on the rigid riser support via the MTL (Lateral Locking Module) and contains the curvature stiffener locking system. The hang-off adapter in the Diverless Unified Support Tube (TSUDL) plays a fundamental role in stabilizing and supporting rigid and flexible risers. Integrated into the system's centralizer, it uses the MTL to center the adapter on the rigid riser support, ensuring stability during FPSO operations. However, document BR102021017344A2 does not propose the use of pivoting wedges and a differential angle between the wedges, as proposed in this Utility Model.

[0009] Document BR102021017361A2 presents a mechanism for retracting the wedges of a rigid riser support, consisting of a cam-carrying crown, rods with rollers, a drive spindle, a hydraulic actuator, and springs. This system can be operated by ROV or remotely. The invention's system allows for a reduction in the need for shallow diving. However, document BR102021017361A2 fails precisely because it does not adopt the concept of pivoting wedges and a differential angle between wedges, as proposed in this Utility Model.

[0010] Therefore, it is evident that the State of the Art documents completely fail to present a mechanism capable of replacing the sliding motion of the wedges with a pivoting motion, operated by hydraulic cylinders and individual springs. The present Utility Model is less sensitive to the growth of marine life, eliminating the need for special biocidal materials and simplifying the manufacture and maintenance of the equipment. Furthermore, its simplified geometric design and the reduction in the number of components increase the robustness and reliability of the system, allowing for easier testing and cleaning of the wedges before pull-in operations. SUMMARY OF THE UTILITY MODEL

[0011] This utility model relates to a cone with a pivoting mechanism for supporting a Hang-Off Adapter (HOA) in diverless operations, comprising an upper cone designed to transmit the vertical load of the HOA to a support tube. Wedges are mounted on the upper cone, configured to support the vertical load of the HOA and center its position. Hydraulic cylinders, connected to the wedges, allow the wedges to move between an open and a closed position, facilitating pull-in and pull-out operations of the riser. Associated with the hydraulic cylinders, springs return the wedges to the closed position when the cylinders are depressurized. Pivoting rods, connected to the hydraulic cylinders and the wedges, transfer the movement from the cylinders to the wedges. A wedge-holder crown, fixed to the upper cone, supports the pivoting rods and the hydraulic cylinder and spring assemblies.

[0012] The wedge pivoting mechanism allows for efficient opening and closing. The wedges have a differential angle between the upper and lower faces, varying between 2 and 5 degrees. This wedge offset angle reduces the risk of HOA displacement, since with this geometry it will be intrinsically locked. Furthermore, the hydraulic cylinders are double-acting, providing more precise and effective control of the mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present utility model will now be described with reference to its typical embodiments and also with reference to the accompanying drawings, in which:

[0014] Figure 1 is a representation of the locking mechanism of the State of the Art.

[0015] Figure 2 is a representation of the cone with a pivoting mechanism of the present Utility Model.

[0016] Figure 3 is a representation of the wedges of the present Utility Model in the open position. DETAILED DESCRIPTION OF THE UTILITY MODEL

[0017] The current upper locking system in TSUDL, as depicted in Figure 1, features a wedge retraction mechanism consisting of: a cam-carrying crown (10), rods (12) with rollers (14) guided by rails, an actuating spindle (16) and springs (18), this system can be actuated by ROV, thus eliminating the need for diving. The actuating spindle (16) can also be replaced by a hydraulic actuator, which can then be operated by a panel installed on the UEP itself, also eliminating the need for a vessel with an ROV. This concept, however, is highly sensitive to the growth of marine life, which can cause many instances of wedge movement jamming.

[0018] In this sense, in view of the technical problem presented, the present Utility Model refers to a cone with a pivoting mechanism for supporting the Hang-Off Adapter (HOA) in diverless operations, as shown in Figure 2, with the wedges in the closed position. The proposed cone consists of several interconnected elements that work together to support the hang-off adapter (HOA) safely and efficiently. Among the cone components are: wedges (20), upper cone (22), hydraulic cylinders (30) and springs (24), pivoting rods (26), and a wedge-holder crown (28).

[0019] The wedges (20) are critical components that support the vertical load of the HOA and center its position on the upper cone (22). The upper cone (22) is the structure that transmits the vertical load of the HOA to the TSUDL. The upper cone (22) was optimized to reduce the space required to avoid interference with adjacent structures on the riser balcony.

[0020] The wedge movement mechanism is actuated by hydraulic cylinders (30) and springs (24). The hydraulic cylinders (30) are responsible for the opening movement of the wedges to allow pull-in and pull-out operations of the riser. When the hydraulic cylinders (30) are pressurized, the pivoting rods (26) connected to the wedges move, causing them to open. Depressurization of the hydraulic cylinders (30) allows the springs (24) to return the wedges (20) to the HOA support position. Alternatively, a double-acting hydraulic cylinder can be used, eliminating the need for springs and allowing the wedges to close by pressurizing the cylinders in the closing direction.

[0021] The pivoting rods (26) transfer the movement of the hydraulic cylinders (30) to the wedges (20), promoting a pivoting movement instead of sliding, which reduces the risk of jamming caused by the growth of marine life. The wedge-carrying crown (28) is fixed to the upper cone (22) and supports the pivoting rods (26) as well as the hydraulic cylinder / spring assemblies. The wedge-carrying crown (28) also assists in maintaining the position of the wedges during operation.

[0022] In the pull-in operation, the movement of the cone mechanisms begins with the pressurization of the hydraulic cylinders, which actuate the pivoting rods connected to the wedges. This pivoting movement opens the wedges, as can be seen in Figure 3, allowing the HOA to be suspended by the winch and positioned inside the cone. This approach ensures precise and safe control of the wedge movement during both operations, minimizing the risk of accidental contact with the pull-in system cable and increasing the reliability and safety of the riser support system. After the HOA is pulled into the desired position, the depressurization of the hydraulic cylinders and the action of the springs close the wedges. After the wedges close, the HOA is positioned on the wedges, ensuring that the HOA is firmly supported and centered in the upper cone.

[0023] In the pull-out operation, the process is reversed: the winch raises the HOA, allowing it to be suspended over the wedges of the upper cone. The hydraulic cylinders are pressurized again to open the wedges. The winch then lowers the HOA through the support tube, allowing it to be removed from the upper cone. Once the HOA is completely removed, the wedges can be closed again by depressurizing the hydraulic cylinders and by the action of the springs, returning to the working position and preparing the cone for the next operation.

[0024] This new support mechanism offers several advantages over the current system. First, sensitivity to marine life growth is significantly reduced, eliminating the need for components made from complex and expensive biocidal materials. For areas exposed to water, anti-fouling paint is applied, simplifying equipment manufacturing.

[0025] The geometric complexity and the number of components in the new system are considerably lower, facilitating manufacturing and parts supply. In the case of field maintenance, component replacement is faster and the response time for divers or ROVs is reduced.

[0026] Another significant advantage is the reduction in space required on the riser balcony, due to the angle of the wedges. This angle has been optimized to minimize the risk of contact between the FPSO pull-in system cable and the wedges, especially in direct vertical pull-in operations from the rigid riser, without the need for a deflection pulley.

[0027] The new cone also incorporates a differential angle between the upper and lower faces of the wedges, varying between 2 and 5 degrees. Along with the extension of the lateral faces of the wedges, this configuration results in an intrinsically locked support ring as soon as the HOA rests on the wedges. This eliminates the possibility of movement of the wedges within the cone, providing more secure riser support.

Claims

CLAIMS 1. Cone with pivoting mechanism for supporting Hang-Off Adapter (HOA) in diverless operations characterized by comprising: an upper cone (22) configured to transmit the vertical load of the HOA to a support tube; wedges (20) mounted on the upper cone (22), configured to support the vertical load of the HOA and center its position on the upper cone; hydraulic cylinders (30) connected to the wedges (20), configured to move the wedges (20) between an open position and a closed position, allowing pull-in and pull-out operations of the riser; springs (24) associated with the hydraulic cylinders (30) configured to return the wedges (20) to the closed position when the hydraulic cylinders (30) are depressurized; pivoting rods (26) connected to the hydraulic cylinders (30) and to the wedges (20), configured to transfer the movement of the hydraulic cylinders (30) to the wedges (20);1. A wedge-holder crown (28) fixed to the upper cone (22), configured to support the pivoting rods (26) and the hydraulic cylinder (30) and spring (24) assemblies.

2. Cone with pivoting mechanism for supporting Hang-Off Adapter (HOA) in diverless operations, according to claim 1, characterized in that the wedge pivoting mechanism allows the opening and closing of the wedges.

3. Cone with pivoting mechanism for supporting Hang-Off Adapter (HOA) in diverless operations, according to claim 1, characterized in that the wedges; (20) have a differential angle between the upper face and the lower face, varying between 2 and 5 degrees.

4. Cone with pivoting mechanism for supporting Hang-Off Adapter (HOA) in diverless operations, according to claim 1, characterized in that the hydraulic cylinder (30) is a double-acting hydraulic cylinder.

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