Casing Window Assembly with Expandable Inner Sleeve
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Solution Overview
Problem
Conventional casing window assemblies for wellbores require milling, have high costs for separate trips to retrieve components, and face challenges in achieving proper lateral position and depth due to torque issues during drilling.
Innovation Solution
A casing window assembly with a tubular casing sleeve and an inner sleeve that can be releasably secured using an expandable wall and securing elements, eliminating the need for milling and allowing for secure positioning without additional trips, featuring a high-pressure rating and improved orientation through a mandrel and orienting member with expandable stop and orienting-keys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional casing window assembly with an outer aluminum sleeve is used, then the annulus is protected from debris and cement, but the outside diameter increases and the pressure rating decreases
Solution Approach 1:
The patent uses a disposable plastic liner that is intentionally designed to be removed after serving its protective function during cementing. The liner provides temporary protection against debris and cement contamination but is not intended for permanent retention, thus avoiding the pressure rating limitations of aluminum sleeves while maintaining protection during the critical cementing operation.
Solution Approach 2:
The invention employs a composite structure combining a metal casing with a plastic liner. The metal casing provides the structural strength and pressure rating, while the plastic liner provides the protective function during cementing. This composite approach allows each material to contribute its superior properties without compromising the other.
2Ease of operation
If a pre-milled window is created in the casing, then tool entry is enabled, but additional trips are required to retrieve components and milling operations are needed
Solution Approach 1:
The patent incorporates a pre-formed opening in the casing that is prepared in advance during casing manufacturing, eliminating the need for on-site milling operations. The opening is designed to accommodate tool entry directly, so when the casing is installed, tools can be entered without requiring additional trips or milling equipment, thus saving time and operational complexity.
Solution Approach 2:
The invention combines the opening formation and tool entry capability into a single integrated design feature of the casing itself. Rather than requiring separate operations for creating the opening and enabling tool entry, the pre-formed opening provides both functions simultaneously, eliminating redundant steps in the completion process.
3Reliability
If an inner steel sleeve is used to protect the inside of the casing, then the seal is improved and pressure rating increases, but a separate trip is required to retrieve the sleeve
Solution Approach 1:
The patent uses a disposable plastic liner instead of a retrievable steel sleeve. The liner provides adequate sealing and protection during the cementing operation but is designed to remain in place or be easily removed without requiring a separate retrieval trip. This eliminates the costly and time-consuming operation of fishing out a steel sleeve while maintaining the necessary seal integrity during the critical cementing phase.
Solution Approach 2:
The invention extracts the retrieval function from the protective liner design. Rather than designing a sleeve that must be retrieved, the patent uses a liner that is either left in place as a permanent seal or can be removed through simple operations. This extraction of the retrieval requirement eliminates the need for separate fishing trips while still providing the necessary protection and sealing functions.
4Measurement precision
If conventional orienting members are used for lateral position and depth orientation, then orientation is provided, but torque buildup causes difficulty in achieving proper positioning in deeper wells
Solution Approach 1:
The patent segments the orientation function into separate components: lateral position orientation and depth orientation. The casing opening is positioned at a specific lateral location on the casing, providing inherent lateral orientation. Depth orientation is achieved through separate positioning of the opening relative to the casing end. This segmentation allows each orientation function to be optimized independently, reducing the torque problems associated with trying to achieve both orientations simultaneously through a single mechanism.
Solution Approach 2:
Instead of using a complex orienting member that tries to control both lateral position and depth simultaneously (which creates torque issues), the patent inverts the approach by using the casing opening's fixed position on the casing body to provide lateral orientation inherently. The opening's location on the casing circumference automatically provides the correct lateral angle without requiring active orientation mechanisms, thereby eliminating the torque buildup problem.
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 completion of lateral wellbores without milling, reduces retrieval costs, and facilitates precise orientation without torque-related delays, achieving a high-pressure rating and efficient installation.
Implementation Method 1
an end of the recessed wall profile includes a shoulder; and ii) an inner sleeve releasably secured within the casing sleeve by the expandable wall or the securing element
Data Source
AI summary
A casing window assembly for completion of a lateral wellbore. The casing window assembly includes a tubular casing sleeve with a casing window and an inner sleeve releasably secured within the casing sleeve at a pre-released position adjacent the casing window.