Wellhead Wicker Sealing Surface High-Pressure Design
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Solution Overview
Problem
Conventional annular seals in hydrocarbon production wells face challenges in maintaining a high-pressure seal due to the limitations in yield strength and durability of wickers and sealing rings, which can lead to deformation and failure under high wellbore pressures and potential damage from objects like drill bits.
Innovation Solution
The use of high-strength wickers and annular sealing rings made from materials like austenitic nickel-chromium-based alloys with increased yield strength and hardness, which are deposited as inlays on the wellhead housing and casing hanger, allowing for a tighter seal and greater resistance to axial movement and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If conventional wickers and sealing rings are used, then the seal can be formed, but the seal cannot withstand high wellbore pressures due to limited yield strength
Solution Approach 1:
The patent applies parameter changes by transitioning from conventional steel wickers to tungsten carbide wickers, fundamentally changing the material parameter (yield strength, hardness) to enable the seal to withstand higher wellbore pressures without deformation or failure
Solution Approach 2:
The patent uses composite materials by combining tungsten carbide particles with a metallic binder (such as nickel or cobalt) to create a composite wicker material that exhibits both high compressive strength and toughness, allowing it to resist high pressures while maintaining structural integrity
2Reliability
If softer metal seal is used to allow deformation against wickers, then sealing is achieved, but the wickers can be damaged by objects like drill bits
Solution Approach 1:
The patent changes the hardness parameter of the wickers by using tungsten carbide, which has extremely high hardness and toughness, making it resistant to damage from external objects like drill bits while still allowing the softer seal material to deform and form a reliable seal
3Stress or pressure
If conventional sealing rings are used, then the seal can function, but the rated working pressure is limited
Solution Approach 1:
The patent applies parameter changes by using austenitic nickel-chromium-based alloy for the sealing ring, which has superior strength and toughness properties compared to conventional materials, enabling the seal to maintain reliability at higher rated working pressures
Solution Approach 2:
The patent employs composite material principles in the austenitic nickel-chromium-based alloy, which combines nickel and chromium elements to create a material with enhanced mechanical properties including higher strength, better ductility, and improved resistance to high-pressure environments
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 configuration enables the seal to withstand higher wellbore pressures and resist damage better, maintaining a tighter seal and ensuring greater durability against scratches and impacts, thus enhancing the overall sealing performance and reliability.
Implementation Method 1
high-strength wickers and annular sealing rings made from materials like austenitic nickel-chromium-based alloys with increased yield strength and hardness, which are deposited as inlays on the wellhead housing and casing hanger
Implementation Method 2
The annulus seal is made of a sufficiently deformable metal to allow it to deform against the wickers of the casing hanger. The deformation occurs as the wickers 'bite' into the annulus seal.
Data Source
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AI summary
A wellhead system comprising an outer wellhead housing (54), an inner wellhead member (56), and an annulus therebetween. The inner wellhead member (56), such as a casing hanger, is adapted to land in the outer wellhead housing (54). The outer wellhead housing (54) may comprise a wickers (52) formed in a hardened metal inlay (68). Alternatively, or in addition to the wickers (52) formed in the outer wellhead housing, wickers (50) may be formed in a hardened metal inlay (72) in the inner wellhead member (56). An annular metal seal (64) may be disposed in the annulus and driven into the wickers (52) to seal the annulus between the inner wellhead member (56) and the outer wellhead housing (54) and to axially restrain the seal (64) within the annulus.