Self-Locking Wedge for Wellhead Lockdown Ring Seal Integrity
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Solution Overview
Problem
The existing systems for wellhead hangers face challenges in accurately aligning casing hangers with wellhead housings due to debris, leading to variations in position, which results in relative movement under pressure, degrading the seal and causing shuttling of hangers, especially when relying on play between protrusions and grooves.
Innovation Solution
A reusable retention system with a wedge that expands the lockdown ring inward to fill its split, providing hoop strength and resisting movement, eliminating the need for an actuator ring and addressing hoop and circumferential stresses, allowing for precise locking and actuation across a larger range of positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If play is allowed between protrusions and grooves to simplify installation, then ease of operation is improved, but relative movement occurs under pressure causing seal degradation
Solution Approach 1:
The patent removes the actuator ring component from the system and replaces it with a wedge mechanism that directly engages the lockdown ring. This extraction simplifies the overall system while maintaining reliable sealing through the wedge's ability to provide continuous radial force without requiring play between components.
Solution Approach 2:
The wedge acts as an intermediary element between the locking mechanism and the lockdown ring. It provides the necessary force transmission to maintain seal integrity by engaging the separation in the lockdown ring and providing continuous radial force to prevent relative movement between protrusions and grooves.
2Ease of manufacture
If a split lockdown ring is used to allow wedge engagement, then ease of manufacture is improved, but hoop strength is reduced requiring additional members
Solution Approach 1:
The patent combines the wedge and the lockdown ring into an integrated system where the wedge engages the separation in the lockdown ring. The wedge's tapered geometry merges the functions of providing radial force and maintaining hoop strength, eliminating the need for additional locking members or actuator rings while preserving the structural integrity of the split lockdown ring.
3Reliability
If an actuator ring is used to compress the lockdown ring, then device complexity is increased, but retention reliability is improved
Solution Approach 1:
The patent extracts and removes the actuator ring from the system, replacing its function with a simpler wedge mechanism. The wedge directly engages the separation in the lockdown ring and provides the necessary compressive force through its tapered geometry, achieving reliable retention with fewer components and reduced device complexity.
Solution Approach 2:
The wedge is designed to self-lock within the separation of the lockdown ring through its tapered geometry. Once inserted, the wedge automatically provides the necessary compressive force on the lockdown ring without requiring additional actuating mechanisms, making the system self-sufficient and eliminating the need for an actuator ring.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system ensures a secure and stable seal by resisting axial and vertical movements, maintaining the integrity of metal-to-metal seals and allowing for accurate placement and retention of wellhead components without additional locking members, even under pressure loads.
Implementation Method 1
A reusable retention system with a wedge that expands the lockdown ring inward to fill its split, providing hoop strength and resisting movement
Implementation Method 2
A wedge to be used with a lockdown ring... The wedge includes a stopping feature to enable the wedge to be in one of a number of positions within the separation in the lockdown ring
Data Source
AI summary
A wedge to be used with a lockdown ring is disclosed. The lockdown ring is to be used with a wellhead. The wedge is enabled to engage a separation in the lockdown ring. The wedge includes a stopping feature to enable the wedge to be in one of a plurality of positions within the separation in the lockdown ring.