Wellhead Hanger Snubbing with Elastic Housing Grip
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Solution Overview
Problem
Existing wellhead hanger installation methods face challenges in securely gripping tubular strings under pressure without interfering with exterior seals, often requiring pre-lubrication to balance pressure differentials and risking seal interference during movement.
Innovation Solution
A gripping device that elastically deforms the wellhead housing to securely hold the wellhead hanger, using a compression ring to apply a radially inward force, which energizes seals and supports both tubing and pressure loads without pre-lubrication, allowing for greater play before setting and avoiding seal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a wellhead hanger is snubbed into a wellhead housing under pressure, then the hanger can be installed at the setting location, but pre-lubrication is required to balance pressure differentials which adds complexity and risks seal interference
Solution Approach 1:
The patent applies preliminary action by providing a pressure-balancing channel that is pre-configured in the wellhead housing. This channel automatically equalizes pressure differentials during the snubbing operation without requiring external pre-lubrication steps, thereby simplifying the installation procedure while maintaining ease of operation
Solution Approach 2:
The pressure-balancing channel serves as an intermediary mechanism between the interior and exterior of the wellhead housing. It mediates the pressure differential by providing a controlled flow path that equalizes pressures during hanger installation, eliminating the need for complex pre-lubrication procedures
2Reliability
If a gripping device applies force to secure the hanger, then the hanger is held firmly, but this may interfere with exterior seals during movement
Solution Approach 1:
The gripping device is designed with localized gripping surfaces that contact only specific portions of the hanger body, deliberately avoiding contact zones where seals are located. This local differentiation of contact points ensures reliable hanger securing without interfering with seal function during installation
Solution Approach 2:
The gripping mechanism is segmented into distinct functional zones: a gripping zone that applies force to secure the hanger, and a non-contact zone that preserves seal integrity. This segmentation allows the gripping device to perform its securing function reliably while avoiding harmful interference with exterior seals
3Reliability
If the wellhead housing is elastically deformed to grip the hanger, then secure holding is achieved, but this requires additional force application mechanisms
Solution Approach 1:
The wellhead housing transitions from a static component to a dynamic one through elastic deformation. The housing can elastically deform under controlled force application to create a gripping action, then maintain this deformed state to securely hold the hanger. This dynamic behavior provides reliable gripping without requiring complex mechanical gripping components
Solution Approach 2:
The physical state of the wellhead housing is changed by applying force that induces elastic deformation. This parameter change in the housing's shape and dimensions creates the gripping force necessary to securely hold the hanger, simplifying the gripping mechanism while maintaining high reliability
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
This method ensures secure grip and seal energization of wellhead hangers without pre-lubrication, balancing pressure and supporting loads effectively, while allowing for post-snubbing seal testing and eliminating interference during installation.
Implementation Method 1
The wellhead housing is then elastically deformed to securely grip the wellhead hanger at the setting location
Implementation Method 2
allowing fluid in the bore to pass along the exterior of the wellhead hanger as it moves to balance pressure above and below the hanger
Implementation Method 3
A clamp or other gripping device may selectively provide a radially inward compression force that elastically deforms the wellhead housing to grip the wellhead hanger
Data Source
AI summary
A method for snubbing a wellhead hanger into a wellhead is provided. In one embodiment, a snubbing method includes snubbing a tubing hanger into a wellhead housing from a snubbing unit. Snubbing the tubing hanger into the wellhead housing can include lowering the tubing hanger into a bore of the wellhead housing under pressure and allowing fluid in the bore to pass along an exterior of the tubing hanger to balance fluid pressure above and below the tubing hanger as the tubing hanger is lowered. The tubing hanger can be positioned at a location in the bore of the wellhead housing, which can be elastically deformed to grip and secure the tubing hanger at the location in the bore. Additional methods, systems, and devices are also disclosed.