Expandable Tubular Thread Protection via Centralizing Rings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for protecting expandable tubular threads from scarring during well bore construction are inadequate, as they often result in uneven adhesive application, loose protection sleeves, and increased risk of thread damage due to pressure and handling issues.
Innovation Solution
The method involves creating centralizing rings with a larger outer diameter than the tubular, which hold a steel sleeve in place using adhesive applied through an input port and tell holes, ensuring full coverage and preventing the sleeve from becoming dislodged during downhole placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a steel protection sleeve is attached using adhesive applied with a brush or paddle stick, then the box OD is protected from scarring, but the adhesive coverage is uneven and the sleeve may become loose
Solution Approach 1:
The patent introduces a centralizer as an intermediary component between the protection sleeve and the tubular. The centralizer provides a stable mounting structure with circumferential engagement features that securely hold the protection sleeve in place, eliminating the reliability issues of adhesive-only attachment while maintaining thread protection.
Solution Approach 2:
The patent extracts the attachment function from the adhesive alone and transfers it to the centralizer's mechanical engagement features. The centralizer's circumferential engagement features (teeth or lugs) that engage with the tubular's external features provide a more reliable mechanical attachment system, separating the protection function from the attachment function.
2Ease of manufacture
If adhesive is applied manually with a brush or paddle stick, then the sleeve can be attached to the box OD, but the glue coverage is uneven and may be pushed off during sleeve installation
Solution Approach 1:
The centralizer acts as an intermediary that eliminates the need for manual adhesive application. The mechanical engagement features of the centralizer provide secure attachment without requiring uniform adhesive coverage, removing the source of manufacturing precision problems while maintaining ease of manufacture through simplified installation.
Solution Approach 2:
The patent replaces the chemical adhesive system with a mechanical engagement system. The centralizer's circumferential engagement features (teeth or lugs) mechanically interlock with the tubular's external features, substituting the unreliable adhesive bonding mechanism with a robust mechanical attachment that ensures precise and uniform sleeve positioning.
3Object-affected harmful factors
If the protection sleeve is installed with adhesive, then thread protection is provided, but the sleeve may break loose under pressure during downhole placement
Solution Approach 1:
The centralizer serves as a mediator that transfers the retention strength requirement from the adhesive-sleeve interface to the centralizer-tubular interface. The centralizer's mechanical engagement features with the tubular's external features provide superior strength under downhole pressure, while the centralizer simultaneously secures the protection sleeve, maintaining thread protection without the risk of sleeve loosening.
Solution Approach 2:
The patent creates a composite attachment system combining the centralizer's mechanical engagement features with the protection sleeve. This composite structure distributes the mechanical loads and pressure forces across multiple engagement points, significantly enhancing the overall retention strength compared to adhesive-only attachment, while maintaining the protective function.
Data Source
AI summary
For protecting a tubular or a component attached to the tubular, two sections of the expandable tubular are formed into two complete centralizing rings or two partial centralizing rings having a larger outer diameter than the remainder of the expandable tubular. A sleeve is placed over a box thread of the tubular or over the component. An adhesive fully covers the space between the inside diameter of the sleeve and the outside diameter of the box thread or component. The sleeve remains in place when the tubular is placed down hole.