Multi-Acting Circulation Valve for Subterranean Pressure Control
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Solution Overview
Problem
Existing gravel packing systems experience well swabbing issues during the pickup of inner strings, leading to a drop in formation pressure due to fluid loss, as flapper valves often fail to remain open or are inadvertently closed, causing significant pressure reduction.
Innovation Solution
A multi-acting circulation valve system that allows deliberate control over the wash pipe valve, requiring a predetermined force to be held for a finite time to arm the valve, which then closes only after specific movements, preventing fluid loss and maintaining pressure during operations like gravel packing and production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flapper valve is used in the wash pipe to prevent fluid loss, then fluid loss is reduced, but the valve fails to remain open or is inadvertently closed causing well swabbing and pressure drop
Solution Approach 1:
A retaining sleeve is introduced as an intermediary component between the flapper valve and the wash pipe. The sleeve has a bore that selectively receives and retains the flapper valve in the open position, preventing it from failing to remain open or being inadvertently closed. This mediator ensures reliable valve positioning while maintaining the ability to control fluid flow.
Solution Approach 2:
The retaining sleeve is pre-configured with a bore that is initially positioned to retain the flapper valve in the open position before gravel packing operations. This preliminary positioning ensures the valve is ready to prevent well swabbing from the outset, and the sleeve can be selectively shifted later to close the valve when needed.
2Productivity
If the inner string is picked up to reverse excess gravel, then gravel removal is enabled, but formation pressure drops due to fluid loss through the open wash pipe valve
Solution Approach 1:
The system provides operational feedback through a controlled sequence: the retaining sleeve is shifted to close the wash pipe valve only after the inner string has been picked up sufficiently and before gravel reversal begins. This feedback mechanism ensures the valve closes at the appropriate moment to prevent pressure loss during gravel removal operations.
Solution Approach 2:
The retaining sleeve is designed to be selectively shiftable between open and closed positions, allowing dynamic control of the wash pipe valve. This dynamic positioning enables the system to adapt to different operational phases: keeping the valve open during setup and closing it during gravel reversal to maintain formation pressure.
3Ease of operation
If a shear pin is used to hold the retaining sleeve in position, then the sleeve is retained, but the shear pin is inadvertently sheared releasing the flapper and causing swabbing
Solution Approach 1:
The retaining sleeve is designed to be manually or mechanically shifted by operational personnel to control the flapper valve position. This self-service design gives operators direct control over valve timing, eliminating the unreliable automatic shear pin mechanism that could be inadvertently activated. The system serves itself through operator awareness and control.
Data Source
AI summary
A valve on an inner string can only be closed with multiple movements in opposed directions that occur after a predetermined force is held for a finite time. Holding the force against resistance eventually allows movement that arms the valve. A set down and pickup force will then close the valve. The surrounding string has a constriction that interacts with a j-slot to rotate a wedge with a first peak into alignment with a peak on a second wedge that can only translate against a spring bias. The second wedge is eccentrically linked to a ball that rotates between and open and a closed position.