Ball Valve Safety Plug Shear Mechanism
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Solution Overview
Problem
Ball valves used in wellbore operations often fail to establish fluid communication between the surface and subterranean formations, leading to operational challenges during drilling and production, particularly due to failure in actuating from a closed to an open position.
Innovation Solution
A ball valve design incorporating a flow through device with a plug and shear device, which includes a shear ring or pin, allows for fluid communication by shearing the shear device when a pressure threshold is exceeded, disengaging the plug and enabling fluid flow through the valve even when it is in a closed position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ball valve is used to control fluid flow in wellbore operations, then fluid communication can be established and isolated between surface and formation, but the valve may fail to actuate from closed to open position, reducing reliability
Solution Approach 1:
The patent incorporates a flow through device with a plug and shear device (shear ring or pin) that is pre-configured within the ball valve. This preliminary action mechanism allows the valve to automatically fail-safe by shearing the retention device when pressure differential exceeds a threshold, enabling the plug to disengage and restore fluid flow without requiring external intervention or complex control systems.
Solution Approach 2:
The ball valve design enables self-service operation through the pressure-actuated flow through device. When the valve fails to open or becomes stuck in the closed position, the accumulated pressure differential automatically acts on the plug to shear the retention device, allowing the plug to disengage and restore flow. This self-activating mechanism eliminates the need for external downhole tools or complex control systems to intervene.
2Reliability
If a ball valve fails to establish fluid communication, then operational challenges occur during drilling and production, but adding complex safety mechanisms increases device complexity
Solution Approach 1:
The patent segments the ball valve into distinct functional components: the ball with flow passages, the plug, the shear device (shear ring or pin), and the retention mechanism. This segmentation allows each component to perform its specific function independently while maintaining overall system simplicity. The shear device is a separate, simple mechanical element that can be easily designed and manufactured without adding significant complexity to the overall valve structure.
Solution Approach 2:
The plug acts as an intermediary element between the pressure differential and the ball valve actuation. It is retained in a position that blocks flow passages but can be disengaged by shearing the retention device. This intermediary mechanism provides a simple, reliable way to restore flow without requiring complex control systems or multiple moving parts.
3Productivity
If downhole tools or milling are used to re-establish fluid communication, then fluid flow can be restored, but the procedure becomes costly and time-consuming
Solution Approach 1:
The ball valve design enables self-service operation through the pressure-actuated flow through device. When the valve fails to open or becomes stuck in the closed position, the accumulated pressure differential automatically acts on the plug to shear the retention device, allowing the plug to disengage and restore flow. This self-activating mechanism eliminates the need for external downhole tools or complex control systems to intervene.
Solution Approach 2:
The shear device (shear ring or pin) is designed as a disposable, low-cost component that is sacrificed to restore valve operation. Rather than requiring expensive downhole tools or milling operations, the simple shear device shears at a predetermined pressure threshold, enabling the plug to disengage and restore flow. This disposable component approach significantly reduces both time and cost compared to traditional workover procedures.
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
This solution ensures reliable fluid communication can be re-established without the need for downhole tools or milling, providing a safety feature to manage pressure and facilitate operations even when the ball valve fails to actuate, thereby enhancing wellbore management and reducing the risk of costly workover procedures.
Implementation Method 1
A ball valve design incorporating a flow through device with a plug and shear device, which includes a shear ring or pin, allows for fluid communication by shearing the shear device when a pressure threshold is exceeded
Data Source
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AI summary
A ball within a ball valve comprises an interior fluid passage extending through the ball, a first flow passage disposed in the ball that allows fluid communication between an exterior fluid and the interior fluid passage, a second flow passage disposed in the ball that extends through a wall of the ball to the interior fluid passage, where the first flow passage and the second flow passage are on opposite hemispheres of the ball, and a flow through device. The flow through device comprises a plug disposed in the second flow passage and configured to sealingly engage the ball, and a shear device configured to engage the plug and retain the plug in the first flow passage or the second flow passage. The shear device may comprise a shear ring, a shear pin or a shear screw.