Upward Biased Lock Mandrel Resolving Flow Instability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lock mandrels face challenges such as requiring a no-go restriction for activation and being susceptible to upward flow-induced instability, which can lead to undesirable retention issues.
Innovation Solution
A lock mandrel assembly with a spring-loaded, upward-moving inner mandrel that sets and locks in a landing nipple profile, allowing for non-selective or selective operation without the need for tapered completion designs, using shear pins and locator dogs to secure the mandrel in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a downwardly travelling inner mandrel is used (prior art), then the mandrel can be run into the well, but upward flow causes the mandrel to become unstable and may lead to retention issues
Solution Approach 1:
The patent inverts the traditional downwardly travelling inner mandrel design by implementing an upwardly travelling inner mandrel. This reversal changes the direction of travel to work with rather than against the upward flow forces, thereby eliminating the instability and retention issues caused by flow-induced movement.
Solution Approach 2:
The patent converts the harmful effect of upward flow into a beneficial force by designing the inner mandrel to travel upward. The upward flow that previously caused instability is now harnessed to drive the mandrel's movement, eliminating the need to fight against the flow direction.
2Reliability
If a no-go restriction is required for mandrel activation, then the mandrel can be set in place, but the system becomes more complex and requires additional downhole components
Solution Approach 1:
The patent removes the no-go restriction component from the system by implementing a trip mechanism that activates the mandrel through rotational movement of the outer mandrel. This extraction eliminates the need for additional downhole restriction components while maintaining reliable mandrel setting.
Solution Approach 2:
The patent introduces a trip mechanism as an intermediary between the surface operation and the mandrel activation. By rotating the outer mandrel, the trip mechanism indirectly activates the inner mandrel's upward movement, providing a simpler alternative to direct no-go restriction activation.
3Adaptability or versatility
If a selective lock mandrel is used, then specific nipple profiles can be targeted, but the operation requires precise positioning and additional control mechanisms
Solution Approach 1:
The patent implements a trip mechanism that allows the operator to self-service the selection process by rotating the outer mandrel to the desired position before activation. This manual positioning approach simplifies the operation compared to automated control systems while maintaining the ability to selectively target specific nipple profiles.
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 solution effectively secures the lock mandrel in a landing nipple profile, resisting upward flow and enabling reliable operation in existing nipple profiles, allowing for multiple nipple usage without design modifications and improved retention features.
Implementation Method 1
a spring (128) disposed within the housing's bore and capable of moving the inner mandrel between the retracted and extended positions
Data Source
Figure 1A~2
Figure 3A~3C
Figure 4~6
AI summary
Selective and non-selective lock mandrel assemblies include a lock mandrel affixing to a running tool. A collet on the tool holds an inner mandrel in a downhole position in the lock mandrel. For the non-selective assembly, a biased key on the lock mandrel extends into a nipple profile, and shoulders on the key and profile stop further run-in. Operators shear a first shear pin on the running tool by jarring down, and the collet moves and releases its hold on the inner mandrel. Freed, the inner mandrel biased by a spring moves to an uphole position, and a flange fits behind the extended key to lock it in the profile. For the selective assembly, the biased key is held retracted until activated using locator dogs on the running tool to engage a transition when running uphole. Once the lock mandrel is set, operators detach the running tool from it.