Expandable Sleeve Float Valve for Wireline Access
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Solution Overview
Problem
Standard float valves in drill strings pose obstacles for wireline operations and directional surveys, as they need to be removed to allow reverse circulation, which is time-consuming and costly, and their small internal diameter restricts tool passage and fluid flow.
Innovation Solution
A drill string sub with an integral flapper and internal sleeve that can be expanded to increase the internal diameter, allowing tools to pass through and deactivate float valves by using a tool to open the flapper and move the sleeve into position, enabling larger tools and improved flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard float valves are used in drill strings, then one-way flow control is achieved, but wireline operations are blocked and tool passage is restricted
Solution Approach 1:
The float valve is designed with a movable flapper that can be dynamically shifted between open and closed positions. A shifting mechanism allows the flapper to be moved off its seat using wireline-conveyed tools, temporarily opening the valve to permit wireline operations, then returning to the closed position to restore one-way flow control. This dynamic repositioning resolves the contradiction between maintaining reliable flow control and enabling wireline accessibility.
Solution Approach 2:
A sleeve mechanism acts as an intermediary between the wireline tool and the flapper valve. The sleeve is conveyed on wireline to the valve location, engages with the flapper to shift it open, performs the necessary operations, then reverses the process to close the valve and retrieve the tool. This intermediary mechanism enables wireline operations without permanently compromising the valve's flow control function.
2Reliability
If standard float valves are used in drill strings, then one-way flow control is achieved, but reverse circulation is prevented
Solution Approach 1:
The flapper valve provides dynamic adaptability by allowing the drill string to operate in two distinct modes: normal mode with the flapper closed for one-way flow control, and reverse circulation mode with the flapper shifted open using a wireline-conveyed ball or tool. This dynamic switching capability enables the system to adapt between conflicting operational requirements without compromising either function.
Solution Approach 2:
The valve's flow characteristics are changed by altering the flapper's position parameter. When the flapper is in the closed position, it provides one-way flow control; when shifted to the open position via wireline intervention, it allows bidirectional flow for reverse circulation. This parameter change enables the valve to meet different operational requirements.
3Volume of moving object
If the float valve is positioned close to the drill string connection, then space is saved, but the internal diameter is reduced limiting tool passage
Solution Approach 1:
The invention resolves the spatial conflict by utilizing the radial dimension through an expandable sleeve. The sleeve is conveyed on wireline through the restricted annular space near the connection, then expanded radially outward to engage and shift the flapper. This dimensional approach allows the valve to be positioned close to the connection for space efficiency while still enabling tool passage through the expanded sleeve pathway.
Solution Approach 2:
The sleeve mechanism is nested within the drill string assembly, conveyed through the existing annular space, and then expanded to perform its function. This nested configuration allows the tool to pass through the restricted space in a compact state, then expand to access and operate the valve mechanism without requiring additional external space.
Data Source
AI summary
An oil field tubular for use as part of a well string, includes a hollow tube that forms a passage, each end of the tube configured for connection to the end of an adjacent string section to form a continuous string; a flapper, integrally connected within the hollow tube so that the flapper can move between an open position where the flapper allows fluids to pass through the hollow tube and a closed position where the flapper closes the passage and prevents passage of fluids therethrough, the flapper spaced away from the end connections of the hollow tube, the hollow tube further including a recess formed into part of the side wall, the flapper and tube configured so that in the open position the flapper locates into the recess.