Radially Expandable Wellbore Lining with Spirally Wound Braid Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sealing solutions for high-temperature and high-pressure wellbores, such as those used in petroleum extraction by steam injection, face challenges with space requirements, elongation rates, and optimal sealing efficiency, particularly at temperatures above 325°C and pressures up to 140 bars.
Innovation Solution
A radially expandable lining device with a spirally wound braid or filament seal, utilizing a combination of materials like graphite and PTFE, and aramid fibers encapsulated in a rubber sheath, which provides high thermal resistance and mechanical strength, allowing for optimal sealing and expansion capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If metal sealing sleeves are used for high-temperature wellbores, then temperature resistance is improved, but wall thickness increases reducing wellbore passage
Solution Approach 1:
The patent employs a thin-walled metal sleeve (3-5mm thickness) combined with a flexible sealing element comprising braided filaments wound spirally around the sleeve. The flexible sealing element can deform radially to conform to the wellbore wall while the thin metal sleeve provides structural support and high-temperature resistance, achieving both temperature resistance and minimal wellbore passage reduction.
Solution Approach 2:
The sealing device combines dissimilar materials: a metal sleeve (stainless steel or Inconel) for high-temperature structural support, and a flexible sealing element made of graphite-impregnated PTFE or aramid fibers for sealing. This composite structure allows the metal component to withstand temperatures up to 600°C while the flexible element provides the sealing function with minimal radial thickness.
2Temperature
If graphite/carbon packing units are used for high-temperature sealing, then temperature and corrosion resistance are improved, but elongation rate decreases reducing expansion capability
Solution Approach 1:
The patent changes the material parameters of the sealing element by using graphite-impregnated PTFE or aramid fibers instead of pure graphite/carbon. These materials maintain high-temperature and corrosion resistance while possessing significantly higher elongation rates (exceeding 10% radial expansion capability), enabling the sealing element to expand and conform to the wellbore wall effectively.
Solution Approach 2:
The sealing element is designed as a flexible braided structure that can deform radially. The braided configuration of filaments allows the sealing element to expand outward by more than 10% of its initial diameter while maintaining structural integrity at high temperatures, directly addressing the elongation rate limitation of traditional graphite/carbon materials.
3Reliability
If elastomer coatings are used for sealing, then sealing quality is improved, but maximum operating temperature is limited to 325°C
Solution Approach 1:
The patent replaces elastomer materials with high-temperature resistant composite materials. The sealing element is made of graphite-impregnated PTFE or aramid fibers, which maintain their mechanical properties and sealing capability at temperatures up to 600°C. These materials do not degrade like elastomers, providing both high-temperature resistance and reliable sealing quality.
Solution Approach 2:
The patent changes the chemical composition and thermal properties of the sealing material. Instead of using organic elastomers that decompose above 325°C, the invention employs inorganic and thermally stable materials (graphite, PTFE, aramid) that can withstand temperatures up to 600°C while maintaining flexibility and sealing effectiveness.
4Stress or pressure
If metal sealing sleeves are used for high-pressure wellbores, then pressure resistance is improved, but installation difficulty increases
Solution Approach 1:
The sealing device is segmented into two independent components: a rigid metal sleeve and a flexible sealing element. The metal sleeve provides the pressure-resistant structural framework, while the flexible sealing element can be independently installed and deformed to achieve sealing. This segmentation allows the flexible element to be easily installed by radial expansion without requiring complex assembly procedures.
Solution Approach 2:
The flexible sealing element is designed as a thin-walled structure that can be radially expanded to fit inside the metal sleeve and against the wellbore wall. This flexible design simplifies installation compared to rigid metal sealing sleeves, as the flexible element can be compressed for insertion and then expanded to its final sealing position using simple hydraulic or mechanical expansion tools.
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 solution achieves efficient sealing at temperatures up to 600°C and pressures over 210 bars, maintaining mechanical and chemical resistance over time, with a thin wall design that preserves wellbore passage and enhances sealing quality by allowing over 20% expansion.
Implementation Method 1
a radially expandable lining... This operation of expansion is achieved in a known way by using conical expansion tools, by hydroforming using a fluid under pressure or again by an expansion vessel called an inflatable packer
Implementation Method 2
said seal comprises at least one first part formed by a filament or a braid mounted spirally about the external surface of said lining... allowing for optimal sealing and expansion capabilities... with a thin wall design that preserves wellbore passage and enhances sealing quality by allowing over 20% expansion
Data Source
AI summary
A device for lining or obturating a wellbore or a pipe. The device includes a tubular radially-expandable lining and at least one ring seal carried by the lining. The seal includes at least one first part formed by a filament or a braid mounted spirally about the external surface of the lining.