Expandable Mill Blades for Full-Circle Wellbore Cleaning
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Solution Overview
Problem
Existing well cleaning technologies are limited in their ability to effectively clean deviated or horizontal wells, fail to provide full coverage, and are ineffective in accommodating turbulent fluid flow or directing debris upward for disposal, often due to design flaws such as incomplete retraction, torque transmission issues, and externally exposed components that can become dislodged.
Innovation Solution
A cleaning apparatus with a tubular housing and spirally-oriented mill blades that are spring-biased radially outward, capable of spanning the entire inner circumference of a cylindrically-shaped well component, allowing for 360-degree cleaning and effective debris removal, with a mechanism for retracting the blades to prevent interference and ensure full coverage, and centralizers to maintain proper positioning and fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mill blades are extended to contact the interior surface for cleaning, then cleaning effectiveness is improved, but the risk of component dislodgment and interference with other equipment increases
Solution Approach 1:
The mill blades are designed to be movable between extended and retracted positions relative to the housing. During cleaning operations, the blades extend radially outward to contact and clean the interior surface. When cleaning is complete, the blades retract to prevent interference with completion equipment and reduce dislodgment risk. This dynamic positioning resolves the contradiction by allowing the system to optimize for cleaning effectiveness during operation and safety during transport.
2Area of stationary object
If mill blades are arranged to span the entire inner circumference for full coverage cleaning, then cleaning coverage is improved, but the structural complexity and torque transmission difficulty increase
Solution Approach 1:
The cleaning system divides the interior circumference into multiple discrete cleaning zones, each served by individual mill blades or blade assemblies positioned at different angular locations. Each blade can be independently supported and controlled, allowing full circumferential coverage without requiring a monolithic complex structure. This segmentation enables manageable torque transmission to each blade while achieving comprehensive cleaning coverage.
3Ease of operation
If mill blades are made retractable to prevent interference with completion equipment, then ease of operation is improved, but the manufacturing complexity and potential malfunction risk increase
Solution Approach 1:
The retraction mechanism employs dynamic positioning capability where mill blades can transition between extended and retracted states. This is achieved through movable blade supports, spring-loaded mechanisms, or actuated positioning systems that allow blades to retract along defined paths. The dynamic design enables the tool to adapt to different operational phases: extended during cleaning for maximum effectiveness, and retracted during transport and completion operations to prevent interference and facilitate easy deployment of subsequent equipment.
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
The apparatus provides comprehensive cleaning of well surfaces, ensuring full coverage and effective debris removal, even in complex well geometries, while maintaining unrestricted fluid flow and preventing component dislodgment, thus enhancing well cleaning efficiency and safety.
Implementation Method 1
Each mill blade is spring-biased radially outwardly from the housing into at least one extended position
Data Source
AI summary
In some embodiments, apparatus useful for cleaning at least part of the interior surface of a cylindrically-shaped member disposed in a subterranean well includes a housing and a plurality of retractable mill blades supported on the housing. The mill blades of such embodiments are capable of cleaning the entire circumference of the interior surface of at least a portion of the cylindrically-shaped member upon reciprocation of the housing.