Downhole Jarring Tool Extensible Joint Latch Mechanism
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Solution Overview
Problem
Drilling operations in harsh environments and deeper well bores increase the risk of tools becoming stuck, leading to equipment damage and operational interruptions, with existing retrieval methods potentially damaging the well bore.
Innovation Solution
A jarring tool with an extensible joint mechanism that generates an impact force through tensile force, utilizing inner and outer latch pieces and a restraining collar to unlatch and relatch, allowing for repeated use in freeing stuck tools without damaging the well bore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fishing techniques are used to retrieve stuck tools, then the stuck tools can be removed from the well bore, but the well bore may be damaged
Solution Approach 1:
The latch mechanism uses asymmetric geometry where the latch piece has a specific shape that allows it to engage with the restraining collar in one direction but release when subjected to impact force from the opposite direction, enabling selective action based on force direction
Solution Approach 2:
The joint transitions from a static latched state to a dynamic extended state and back, allowing the system to adapt its mechanical properties based on the applied load conditions - rigid during normal operation, compliant during impact, and rigid again after resetting
2Adaptability or versatility
If work strings and tools are operated in deeper and harsher well bores, then drilling capability is improved, but the risk of tools becoming stuck increases
Solution Approach 1:
The jarring tool is pre-positioned in the work string before entering problematic well sections, and the latch mechanism is pre-configured to automatically engage and disengage under specific force conditions, providing proactive protection rather than reactive recovery
Solution Approach 2:
The extensible joint acts as an intermediary element between the upper and lower sub ends, absorbing differential movements and reducing the transmission of stuck forces to the well bore while maintaining tool connectivity
3Productivity
If the joint unlatches under tensile force to generate impact force, then stuck tools can be freed, but the joint must be reset to latched position for repeated use
Solution Approach 1:
The latch mechanism is designed to automatically reset through the spring-loaded collet device that pushes the latch piece back through the restraining collar when compressive force is applied, eliminating the need for manual intervention and enabling rapid repeated use
Solution Approach 2:
The tool operates in periodic cycles of latched-stable, extended-impact, and reset-stable states, with each cycle designed to be rapid and automatic, allowing multiple jarring operations without prolonged downtime between interventions
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
Effectively frees stuck tools by generating a significant impact force to dislodge them without causing further damage to the well bore, allowing for repeated use and minimizing downtime in drilling operations.
Implementation Method 1
The collet may be biased toward the inner latch piece by a coil spring
Implementation Method 2
An impact force is generated from the tensile force when the joint unlatches and reaches a maximum extension
Data Source
AI summary
A tool having a first lower sub end, a second upper sub end, and an extensible joint connecting the first and second sub ends. The joint has a first inner latch piece connected to the lower sub end, and a second outer latch piece connected to the upper sub end, and a stationary restraining collar. The joint, in a latched position, has the outer latch piece latched to the inner latch piece and the inner and outer latch pieces restrained from unlatching by the restraining collar. The joint, under tensile force, unlatches into an unlatched position by the inner latch piece pulling the outer latch piece through the restraining collar into a position where the inner and outer latch pieces are free to separate. An impact force is generated from the tensile force when the joint unlatches and reaches a maximum extension.