Downhole Cutting Tool Mechanical Locking Arrangement
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Solution Overview
Problem
Existing downhole cutting tools face issues with axial movement and potential damage or loss due to pressure-induced upwards forces when using inflatable packers, which can affect cutting operations and tool recovery during well decommissioning.
Innovation Solution
A jetting cutting tool with a mechanical locking arrangement that radially expands to engage with the well casing, preventing axial and rotational movement, combined with a sealing arrangement to maintain position and isolate the cutting area, ensuring consistent cutting and safe tool recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an inflatable packer is used to restrain the cutting tool at deployment depth, then the tool can be positioned and sealed within the well casing, but the pressure below the tool creates an upwards force that can cause the tool to slip or be lost upon packer failure
Solution Approach 1:
The patent replaces the inflatable packer restraint system with a mechanical locking arrangement that uses radial expansion of locking elements (such as dogs or grippers) to engage with the well casing wall. This mechanical engagement system eliminates reliance on pressure differentials and packer integrity, providing positive mechanical restraint that prevents both upward slip and rotational movement of the tool during cutting operations.
2Manufacturing precision
If pressure is applied below the tool for de-watering and cutting operations, then abrasive cutting quality is improved, but the tool experiences upward force that compromises stability
Solution Approach 1:
The patent replaces the packer-based pressure restraint system with a mechanical locking system that provides stable tool positioning independent of pressure applications. The mechanically engaged locking elements maintain tool stability regardless of the pressure applied for de-watering or abrasive jet cutting, allowing high-quality cutting operations without compromising tool position.
Solution Approach 2:
The mechanical locking arrangement is engaged before pressure is applied below the tool for cutting operations. This preliminary mechanical restraint counteracts the potential harmful effect of upward force from pressure application, allowing the full benefit of pressurized abrasive cutting to be realized without tool movement or instability.
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 mechanical locking arrangement keeps the tool securely positioned during cutting, preventing axial movement and ensuring effective severance of well casing strings while minimizing the risk of tool damage or loss, and facilitating safe recovery.
Implementation Method 1
a mechanical locking arrangement provided above the nozzle, said locking arrangement comprising radially expandable means selectively engageable with an inner wall of the well casing within which the tool is deployed, to prevent axial and/or rotational movement of the device in the well during cutting operations
Implementation Method 2
a nozzle for directing a jet of an abrasive slurry at the wall of a well casing to sever the well casing
Data Source
AI summary
A cutting tool adapted to be deployed into a well casing for cutting through casing strings comprises a nozzle for directing a jet of an abrasive slurry at the wall of a well casing to sever the well casing and a mechanical locking arranged provided above the nozzle, said locking arrangement comprises radially expandable means selectively engageable with an inner wall of the well casing within which the tool is deployed, to prevent axial and/or rotational movement of the tool in the well during cutting operations.