Jarring Tool Release Mechanism Lug Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing release mechanisms for jarring devices in the well drilling industry, such as those with angular segments, are prone to misalignment, leading to failure under tensile loads, and require additional lug assemblies that increase length and cost.
Innovation Solution
The use of angular lug segments with projections that engage corresponding grooves on the mandrel, positioned within an annular support collar or between adjoining lug segments, to stabilize and prevent misalignment, with grooves and ridges configured to ensure proper alignment and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If angular segments are used in the release mechanism, then the release function can be achieved, but misalignment occurs leading to failure under tensile loads
Solution Approach 1:
A trigger sleeve is introduced as an intermediary component between the mandrel and the release lugs. The trigger sleeve includes a trigger groove that receives the release lugs, providing a precise reference surface that ensures proper alignment and prevents misalignment between segments during operation.
Solution Approach 2:
The trigger sleeve is pre-positioned on the mandrel with the trigger groove already formed at the correct orientation. This preliminary configuration ensures that when the release lugs are inserted, they automatically align correctly without requiring additional alignment operations or adjustments.
2Strength
If two sets of release lugs are used to withstand tensile load, then the load capacity is improved, but the total length of the jar increases significantly
Solution Approach 1:
Instead of spacing lug assemblies further apart along the axial direction (increasing length), the design uses the radial dimension by creating multiple lugs around the circumference of the trigger sleeve. This allows multiple load-bearing points to be distributed in a circular pattern, increasing strength without increasing axial length.
Solution Approach 2:
Multiple release lugs are nested around the trigger sleeve in a circular arrangement, with each lug positioned within the trigger groove at different angular positions. This nested configuration allows multiple lugs to share the tensile load while maintaining a compact axial profile.
3Reliability
If lug assemblies are spaced further apart to prevent inadvertent engagement, then the risk of misalignment is reduced, but the total length and cost increase
Solution Approach 1:
The trigger sleeve serves multiple functions simultaneously: it provides the structural support for the release lugs, provides the precise alignment reference through the trigger groove, and prevents inadvertent engagement by constraining the lugs to a specific circular path. This multi-functionality reduces the need for additional separate components.
Data Source
AI summary
A release mechanism for a jarring tool is formed by a plurality of segmented release lugs. Each lug includes a plurality of axial spaced projections on an inner surface and a plurality of grooves on an outer surface. The projections may have either different widths or may be separated by varying distances and releasably engage corresponding grooves in a mandrel located within a housing of the tool. The release lugs are positioned between a trigger sleeve and the mandrel. In one embodiment, the release lugs are positioned within a support collar. In a second embodiment, the lugs are provided with stabilizing posts and cavities that serve to maintain the lugs in a proper alignment.