Detachable Casing Tool for Wellbore Removal
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Solution Overview
Problem
Current methods for disconnecting casing portions from a wellbore are costly and increase operational complexity, with uncertainty about the shape and condition of severed portions for re-entry purposes, especially in horizontal drilling where conventional methods are inefficient and expensive.
Innovation Solution
A detachable tool system comprising an upper and lower sub-assembly with a collet, support sleeve, and burst disc that allows selective detachment of casing portions without cutting, using pressure to rupture the burst disc and circulate cement, and mechanical or chemical cuts as a secondary mechanism for disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If casing is run all the way to the surface, then casing support and structural integrity are improved, but cost and operational complexity increase
Solution Approach 1:
The casing system is divided into multiple segments: surface casing run to surface, intermediate casing suspended at depth, and production casing in the horizontal section. This segmentation allows each segment to serve its specific function optimally while reducing overall complexity and cost compared to running all casing to surface.
2Ease of operation
If casing is cut mechanically or chemically at depth, then casing removal is enabled, but uncertainty about severed portion shape and condition increases
Solution Approach 1:
The tool system extracts and removes the upper sub-assembly and collet from the wellbore after the lower sub-assembly and casing remain in place. This extraction approach avoids the need for cutting operations at depth, eliminating uncertainty about severed portion conditions while enabling clean casing removal.
3Productivity
If horizontal wells are drilled to reach multiple reservoir points, then well productivity is improved, but well cost increases
Solution Approach 1:
The wellbore is segmented into vertical and horizontal sections with different casing strings optimized for each section. Surface casing handles the vertical section, while production casing serves the horizontal section. This segmentation allows horizontal drilling for multiple reservoir points (improving productivity) while avoiding the cost of running expensive casing through the entire horizontal section.
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 efficient and effective removal of casing portions from the wellbore without cutting, reducing costs and operational complexity, while ensuring reliable disconnection and re-entry conditions.
Implementation Method 1
Pressure within the tool may be increased, and the burst disc may rupture
Data Source
AI summary
Examples describe systems and methods for a tool to remove portions of casing from a wellbore. A tool may include a bottom sub-assembly and casing that selectively detach from a sub-assembly. This may allow for tools and casing within the wellbore to be efficiently and effectively removed from the wellbore without having to cut tools down well.