Packer Milling Tool with Radially Expanding Blocks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing downhole milling tools face challenges in removing packers from wellbores with casing patches, as they often require milling the casing patch itself, risking re-opening leaks or causing damage, and cannot effectively retrieve the packer across internal restrictions.
Innovation Solution
A packer milling tool with a milling body, rotating pins, and a fishing spear that expands radially to mill the packer to its full outer diameter without engaging the casing, allowing for retrieval across the restriction without milling the casing patch, utilizing a spring-loaded system and non-metallic outer surfaces for reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional milling tools are used to remove packers below casing patches, then the packer can be removed, but the casing patch must be milled which risks re-opening leaks or causing damage
Solution Approach 1:
The milling tool employs dynamically adjustable milling elements that can change their radial position between a retracted state for passing through the casing patch restriction and an extended state for milling the packer. This dynamic adjustment allows the tool to adapt its geometry to different operational phases, enabling packer removal below the restriction without damaging the casing patch.
Solution Approach 2:
The milling elements are nested within the tool body during the running phase, allowing the tool to pass through the casing patch restriction in a compact configuration. When milling is required, the elements extend outward from the nested position. This nesting principle enables the tool to traverse the restriction while carrying the capability to mill the packer without engaging the casing.
2Ease of operation
If the packer is placed above the casing patch restriction, then retrieval is easier, but the desired placement depth cannot be achieved
Solution Approach 1:
The tool's dynamic geometry allows it to be configured in a compact state for navigating the restriction and then transformed into an extended milling configuration for packer removal. This dynamic capability enables the packer to be placed at the desired depth below the restriction while maintaining the ability to retrieve it, eliminating the need to compromise placement depth for ease of retrieval.
3Force
If the milling tool engages the casing during milling, then milling force is sufficient, but the casing may be damaged
Solution Approach 1:
The milling elements serve as intermediaries that can be selectively engaged or disengaged from the casing. During the milling operation, the elements are positioned to mill the packer without contacting the casing, utilizing the packer's own structural integrity as the milling target. The elements can be retracted if casing contact is detected, preventing damage while maintaining sufficient milling capability when properly positioned.
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 the removal and retrieval of packers below casing patches without damaging the casing, reducing operation time and preventing accidental side tracking, while maintaining casing integrity and avoiding the need to mill the casing patch.
Implementation Method 1
They rotate between a running position and a milling position using a spring-loaded system
Implementation Method 2
Each of the milling blocks includes a non-metallic outer surface and a hard metallic body
Data Source
AI summary
Tools and methods are described for removing a packer beyond a restriction in a casing of a wellbore. A packer milling tool includes: a milling body with an outer diameter; milling blocks positioned at intervals around a circumference of the milling body, each milling block pivotably attached to the milling body and pivotable between a running position and a milling position; and a wash pipe extending from a downhole end of the milling body. The milling blocks have a rotational circumference with a rotational diameter that is less than the outer diameter of the milling body when in the running position and the rotational diameter is more than the outer diameter of the milling body and less than the inner diameter of the casing when in the milling position.