Double-Acting Jar With Bypass Channels For Repetitive Jarring
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Solution Overview
Problem
Existing double-acting jars in the oilfield industry are complex and unable to perform repetitive upjars and downjars, limiting their functionality in coiled tubing applications where compressive loads are limited and space is constrained.
Innovation Solution
A double-acting jar design featuring an inner mandrel and outer housing with telescopic movement, fluid chamber, and strategically placed restrictions and valves that allow for repetitive jarring operations by enabling fluid pressure differentials to build and release in both directions, with bypass channels to manage pressure and prevent valve jamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a double-acting jar is designed to deliver repetitive upjars and downjars, then operational flexibility and effectiveness are improved, but device complexity increases
Solution Approach 1:
The jar is divided into two independent valve assemblies (uphole valve and downhole valve) that can operate independently. Each valve has its own seating surface, restriction, and bypass channel, allowing the device to perform upjars, downjars, or either direction repeatedly without complex interlocking mechanisms.
Solution Approach 2:
The dual valve design enables the jar to perform multiple functions: delivering upjars, delivering downjars, and resetting in either direction. Both valves share the same basic structure and operate on the same hydraulic principle, making the system versatile while maintaining design simplicity.
2Volume of moving object
If restrictions and valves are placed close together to save space, then device compactness is improved, but valve jamming risk increases
Solution Approach 1:
Bypass channels are introduced as intermediary pathways that allow fluid to flow around the valves. This prevents pressure buildup that could cause valve jamming, while the close spacing of components is maintained for compactness. The bypass channels act as a safety mechanism that mediates between the conflicting requirements of compactness and reliability.
3Volume of moving object
If telescopic inner mandrel and outer housing are used to reduce space, then device size is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The inner mandrel is nested within the outer housing, with both components featuring telescopic sections that allow relative movement. This nesting arrangement reduces the overall device size while the precision requirements are managed through the valve-seating interface design, where close tolerance fitting is concentrated at specific locations rather than throughout the entire telescopic interface.
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
Enables the jar to deliver repetitive upjars and downjars efficiently, adapting to the limited compressive loads and space constraints of coiled tubing operations, and can be reset for subsequent jarring in either direction, enhancing operational flexibility and effectiveness.
Implementation Method 1
a fluid chamber (16) containing fluid and sealed at an uphole end (18) and at a downhole end (20)
Implementation Method 2
The uphole valve (26) has a first seating surface (30) engageable with an uphole facing sealing shoulder (38) in the fluid chamber to seat the uphole valve
Implementation Method 3
The uphole valve (26) has a first exterior surface (36) that fits with close tolerance within the uphole restriction (22) over at least a portion of the first exterior surface (36)
Implementation Method 4
A first bypass (42), defined by at least one of the uphole valve (26), the outer housing (14), and the inner mandrel (12), is exposed when the first seating surface (30) unseats from the uphole facing sealing shoulder (38)
Implementation Method 5
The inner mandrel (12) is at least partially disposed telescopically within the outer housing (14) to define a fluid chamber (16) between the inner mandrel (12) and the outer housing (14)
Implementation Method 6
First jarring surfaces (70, 72) are on the inner mandrel (12) and outer housing (14) respectively for jarring contact with each other during a jar in a first direction (21)
Data Source
AI summary
A double-acting jar comprises an inner mandrel and an outer housing. The inner mandrel is disposed telescopically within the outer housing to define a fluid chamber in between. There is an uphole restriction and a downhole restriction spaced from one another within the fluid chamber. An uphole valve is disposed within the fluid chamber, the uphole valve having a first seating surface engageable with an uphole facing sealing shoulder in the fluid chamber. There is a downhole valve disposed within the fluid chamber, the downhole valve having a second seating surface engageable with a downhole facing sealing shoulder in the fluid chamber.