External Collet High Flow Downhole Lock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional downhole lock assemblies are ineffective for high flow rate injection applications due to their obstructed and non-uniform inner diameters, causing erosional turbulence, poor flow characteristics, and reduced reliability, and the sheared setting components can damage the inner diameter and foul the flow control or safety tool.
Innovation Solution
A high flow downhole lock assembly with all setting components located outside the inner diameter, featuring a mandrel with external collet finger detents and extendable retaining dogs, ensuring an unobstructed and smooth inner diameter for enhanced flow and reduced turbulence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional downhole lock assemblies are used with internal locking components, then the locking mechanism can be compact and integrated, but the inner diameter becomes obstructed and non-uniform causing erosional turbulence and poor flow characteristics
Solution Approach 1:
The locking components (collet and retaining dogs) are extracted from the internal flow path and positioned on the external surface of the mandrel. This allows the inner diameter to remain unobstructed and uniform, eliminating erosional turbulence while maintaining effective locking functionality through external positioning of the setting components.
2Device complexity
If setting components are located inside the inner diameter, then the assembly structure can be compact, but sheared components can damage the inner diameter and foul the flow control tool
Solution Approach 1:
All setting components including the collet fingers and retaining dogs are positioned on the external surface of the mandrel, completely removed from the internal flow path. This extraction prevents sheared components from contacting and damaging the inner diameter or fouling the flow control tool, significantly improving reliability while maintaining assembly compactness through external positioning.
3Device complexity
If conventional lock assemblies with internal components are used, then the structure can be simpler, but flow rates are limited due to obstructed inner diameter
Solution Approach 1:
By moving all locking and setting components to the external mandrel surface, the inner diameter is completely cleared of obstructions. This creates a smooth, uniform flow path that eliminates turbulence and allows for significantly higher injection rates, directly improving productivity while the external components maintain structural simplicity.
4Device complexity
If internal locking components are used, then the assembly can be more compact, but installed reaction forces are increased
Solution Approach 1:
The locking mechanism transitions from an internal radial configuration to an external configuration on the mandrel surface. This dimensional repositioning allows the locking components to engage with the landing nipple from the outside, distributing reaction forces more effectively and reducing the installed reaction forces while maintaining assembly compactness through external positioning.
Data Source
AI summary
A high flow downhole lock assembly includes a mandrel with a plurality of external collet finger detents disposed about an exterior surface and an unobstructed inner diameter configured for flow, an external collet with a plurality of collet fingers disposed about an interior surface, and a dog housing with a plurality of extendable retaining dogs. When transitioning to a set configuration, a portion of the mandrel travels within the external collet, the plurality of collet fingers come to rest in one or more of the external collet finger detents, and the plurality of extendable retaining dogs are extended.