BR-202024017654-U2 - Cone with pivoting mechanism for supporting hang-off adapter (HOA) in diversless operations.

Abstract

The present invention 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 tube; wedges mounted on the upper cone, configured to support the vertical load of the HOA and center its position on the upper cone; hydraulic cylinders connected to the wedges, configured to move the wedges between an open and a closed position, allowing pull-in and pull-out operations of the riser; springs associated with the hydraulic cylinders, configured to return the wedges to the closed position when the hydraulic cylinders are depressurized; pivoting rods connected to the hydraulic cylinders and wedges, configured to transfer the movement of the hydraulic cylinders to the wedges; and a wedge-holder crown fixed to the upper cone, configured to support the pivoting rods and the hydraulic cylinder and spring assemblies.

Inventors

• GILNEI RECKZIEGEL
• DIVINO JOSE DA SILVEIRA CUNHA
• BRUNO PINHO DOS REIS
• JORGE GOMES DE MELO MEDEIROS
• CLAUDIO VIOLANTE FERREIRA

Assignees

• Petróleo Brasileiro S.A. - Petrobras

Dates

Publication Date

20260310

Application Date

20240828

Claims (4)

1. 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 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); 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. 2. Cone with pivoting mechanism for supporting Hang-Off Adapter (HOA) in diverless operations, according to claim 1, characterized in that the pivoting mechanism of the wedges allows the wedges to be opened and closed.
3. 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. 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.

Description

UTILITY MODEL FIELD [01] The present 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. [02] 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 [03] 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 the wedges to be moved remotely during pull-in and pull-out activities, and can be operated by remotely operated vehicles (ROVs), eliminating the need for divers (diverless). [04] In addition to complexity and maintenance, the space required by the current system may limit its applicability in new floating production units (FPSOs) that demand compact and efficient solutions. [05] Thus, there is a clear need for a simplified system, less sensitive to the growth of marine life, which reduces the complexity of manufacturing and maintenance, and which is compatible with the geometry of current riser support systems. STATE OF THE ART [06] 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 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. [07] 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. [08] 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 promotes integration 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 bend 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 the present Utility Model. [09] 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 being able to be actuated by ROV or remotely. The system of the invention 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 the present Utility Model. [010] 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 [011] The present utility model relates to a cone wit