Expandable Tubular Integral Centralizers
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Solution Overview
Problem
Expandable tubulars face issues with scarring and bending during handling and placement due to their high carbon content and limited expansion capabilities, leading to potential damage to casings and seal bores, and existing centralizers often fail to prevent these issues effectively.
Innovation Solution
The design incorporates sections of expandable tubulars with larger outer diameters to form complete or partial centralizing rings that centralize the tubular during use, which expand to match the tubular's diameter, accompanied by seals and anchors to prevent scarring and secure the tubular in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rubber rings or separate centralizers are attached to the expandable tubular, then centralization and sealing are improved, but device complexity and the risk of scarring increase
Solution Approach 1:
The patent combines the centralizer and seal functions directly into the expandable tubular structure by creating an integral bellows section with enlarged outer diameter. This eliminates the need for separate rubber rings or attached centralizers, reducing assembly complexity while maintaining centralization effectiveness. The bellows section serves both as a centralizing element and as a seal when compressed against the casing inner surface.
2Productivity
If the tubular OD is made close to the casing ID to maximize expansion capability, then productivity is improved, but the risk of scarring and damage to casing increases
Solution Approach 1:
The patent introduces an intermediary bellows section with enlarged outer diameter between the expandable tubular and the casing. This bellows section acts as a mediator that prevents direct contact between the tubular and casing during the run-in process, thereby preventing scarring. When expanded, the bellows section compresses against the casing to provide sealing, allowing the tubular OD to be close to casing ID for maximum expansion while protecting against damage.
Solution Approach 2:
The bellows section is pre-formed with a larger outer diameter than the main tubular body before installation. This preliminary geometric modification allows the tubular to be run into the casing without scarring, and when expanded in-situ, the bellows section provides both centralization and sealing functions, enabling close clearance installation without damage risk.
3Strength
If high carbon content material is used in the tubular, then strength is improved, but the tubular eggs out of shape when handled
Solution Approach 1:
The patent provides beforehand cushioning against shape distortion by forming an integral bellows section with enlarged outer diameter that acts as a structural stabilizer. This bellows section prevents the high-strength, low-memory tubular material from egging out during handling and sling operations, maintaining tubular roundness without compromising the high carbon content material's strength properties.
Data Source
AI summary
Herein disclosed is an apparatus comprising an expandable tubular; and at least one section of the expandable tubular having a larger outer diameter than the remainder of the expandable tubular, forming at least one complete centralizing ring or at least one partial centralizing ring. In an embodiment, at least one complete centralizing ring or at least one partial centralizing ring is configured to centralize the expandable tubular when the tubular is in use; and wherein at least one complete centralizing ring or at least one partial centralizing ring has the same diameter as the expandable tubular after the tubular is radially expanded. Also disclosed herein are method of using and method of making the apparatus.