Packer Cup Sealing for Downhole Tubular Expansion Tools
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Solution Overview
Problem
Existing downhole tools for tubular expansion require expensive surface preparation and have limited service life due to the use of chevron seals or o-ring seals, which are costly and prone to leakage.
Innovation Solution
The use of packer cups with a broad surface area to seal a variable volume space between a housing and a piston, where one packer cup is supported from the piston and the other from the housing, providing effective sealing without the need for expensive surface preparation and enhancing service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chevron seals are used to seal the annular space, then sealing function is provided, but expensive surface preparation and high manufacturing cost are required
Solution Approach 1:
The patent replaces expensive, durable chevron seals with cheaper packer cups that can be easily manufactured and installed. The packer cups are designed to be sacrificial components that provide adequate sealing for the service life required, eliminating the need for expensive surface preparation and chrome plating operations.
Solution Approach 2:
The invention changes the sealing mechanism from rigid chevron seals requiring precise surface geometry to flexible packer cups that conform to the surface through pressure-induced deformation. This parameter change from rigid to flexible sealing allows operation with less stringent surface preparation requirements.
2Reliability
If o-ring seals are used to seal the annular space, then sealing function is provided, but service life is significantly reduced due to fluid cleanliness issues
Solution Approach 1:
The patent employs packer cups made of flexible material that can tolerate contamination and maintain sealing function. Unlike o-rings that are highly sensitive to particulate contamination causing leakage, the packer cups' flexible nature allows them to bridge over minor imperfections and maintain seal integrity even in less clean environments.
3Manufacturing precision
If chrome plating is applied to the moving surface, then sealing surface quality is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent eliminates chrome plating by using packer cups that do not require highly polished surfaces. The packer cups are simple, inexpensive components that provide adequate sealing without requiring expensive surface treatment processes, thereby reducing both manufacturing cost and process complexity.
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 solution reduces construction costs and improves the service life of downhole tools by providing reliable sealing with packer cups, allowing for efficient tubular expansion and other subterranean tasks without the need for expensive surface preparation or frequent maintenance.
Implementation Method 1
the broad surface area on each packer cup abuts the surface where relative movement takes place
Implementation Method 2
pressurizing an annular chamber between a housing and a piston that is inside it
Implementation Method 3
Applying pressure in a string that supports this assembly first sets the anchor and then pressurizes an annular chamber
Implementation Method 4
Extension of the piston drives the swage through the tubular
Implementation Method 5
the expansion of tubulars frequently requires force applied to a swage
Data Source
AI summary
A tool for subterranean use employs relative movement between a housing and a piston by pressurizing and removing pressure in a variable volume defined between them. The variable volume is sealed with packer cups preferably with one supported from the piston and the other off the housing and in opposed orientations so that the broad surface area on each packer cup abuts the surface where relative movement takes place. The downhole tasks accomplished with the relative movement can be varied and include tubular expansion, setting packers or shifting sleeves, for example. A single or multiple packer cups are tied to a structure that needs to be driven and building pressure behind a packer cup or reducing pressure ahead of it advance the piston.