Downhole Straddle Assembly Expandable Metal Sleeve Zone Isolation
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Solution Overview
Problem
Existing solutions fail to effectively isolate zones longer than 100 meters in wells without significantly reducing the inner diameter, leading to inadequate sealing and production issues in wells with small diameters.
Innovation Solution
A downhole straddle system comprising expandable metal sleeves integrated between tubular sections, which are more pliant than the sections themselves, allowing for expansion to seal off long zones without substantial reduction in inner diameter, maintaining flow area and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a patch assembly is expanded from multiple tubulars to cover zones longer than 100 metres, then the sealing length is improved, but the tubulars separate during expansion causing inadequate sealing
Solution Approach 1:
The straddle assembly is divided into multiple tubular sections (first tubular section, second tubular section, etc.) that are connected end-to-end. Each tubular section contains an expandable metal sleeve that can be independently expanded. This segmentation allows the assembly to achieve long sealing length while maintaining reliability through modular construction where each segment can be controlled and sealed independently.
2Reliability
If a new production tubing is inserted in the existing production tubing to isolate zones, then the zone isolation capability is improved, but the inner diameter is reduced substantially deteriorating production
Solution Approach 1:
The expandable metal sleeves are designed to be dynamically expandable from a collapsed state during insertion to an expanded sealing state at the target zone. This dynamic transformation allows the device to pass through the wellbore with minimal interference (small outer diameter) and then expand to provide reliable zone isolation (large sealing diameter) without permanently reducing the inner diameter of the production tubing.
3Reliability
If the inner diameter is reduced in small diameter wells to insert isolation devices, then zone isolation is achieved, but further intervention becomes impossible
Solution Approach 1:
The expandable metal sleeves are nested within the tubular sections in a collapsed configuration during insertion, similar to nested dolls. This nested structure allows the isolation device to be inserted through small diameter wells without requiring excessive clearance. Once positioned, the sleeves expand outward to provide sealing while the nested design ensures minimal permanent space occupation, preserving future intervention capability.
4Length of stationary object
If multiple tubular sections are used to expand a patch assembly for long zone isolation, then the sealing length is improved, but the tubulars separate during expansion
Solution Approach 1:
The tubular sections are pre-assembled and connected in a stable, collapsed configuration before insertion into the wellbore. The connections between tubular sections are established and secured in advance, ensuring structural integrity during the insertion and expansion process. This preliminary assembly and connection stabilizes the multi-section structure before it undergoes the expansion transformation.
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
Enables reliable isolation of zones over 50 meters with minimal reduction in inner diameter, ensuring effective zone separation and maintaining well productivity by expanding only the metal sleeves while keeping other tubular connections unexpanded.
Implementation Method 1
The expandable metal sleeve may be expanded by an internal fluid pressure in the tubular pipe
Implementation Method 2
each annular barrier section has a first tubular section part and a second tubular section part, and the expandable metal sleeve is arranged between the first tubular section part and the second tubular section part, creating a distance
Data Source
AI summary
The present invention relates to a downhole straddle assembly for straddling over a zone downhole in a well, the straddle assembly comprising a plurality of tubular sections mounted end to end in succession to form one tubular pipe having a first end tubular section forming a first open end of the tubular pipe, and a second end tubular section forming a second open end of the tubular pipe, said tubular pipe having an outer diameter, wherein the tubular section mounted to the first end tubular section is a first expandable metal sleeve being more pliant than the first end tubular section, and the tubular section mounted with the second end tubular section is a second expandable metal sleeve being more pliant than the second end tubular section. Furthermore, the present invention relates to a downhole straddle system for straddling over a zone downhole in a well and to a downhole straddle method.