Fluid Actuated Circulating Sub Piston Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current downhole devices require breaking the work string to drop devices like plastic balls to divert fluid flow to the annulus, leading to increased costs and operator errors, and have limitations in flow area and port alignment complexity, making them inefficient and prone to seal failures.
Innovation Solution
A downhole device using multiple pistons actuated by increased fluid pressure through a restriction, allowing for larger flow bore and eliminating the need for port alignment, with a secondary sliding sleeve for sealing protection, enabling fluid diversion without dropping devices into the work string.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plastic ball is dropped into the work string to divert fluid flow to the annulus, then fluid diversion is achieved, but the work string must be broken and reconnected, increasing operational complexity and cost
Solution Approach 1:
The downhole device automatically activates upon receiving a plastic ball, using the ball's presence to trigger fluid diversion without requiring surface operations to break and reconnect the work string. The device then self-deactivates after a predetermined time period, eliminating the need for manual intervention to restore normal flow.
Solution Approach 2:
A timer mechanism serves as an intermediary between the plastic ball activation and the deactivation process. The timer automatically controls the duration of fluid diversion, mediating the transition from diverted flow back to normal work string flow without requiring surface intervention.
2Ease of operation
If multiple steel balls are dropped into the work string to remove the plastic ball, then the plastic ball can be removed, but this requires breaking the work string again and increases the number of operations
Solution Approach 1:
The device automatically removes the plastic ball after the predetermined time period expires, using internal mechanisms to restore normal work string flow without requiring additional steel balls or work string disconnection. The system serves itself by autonomously returning to its initial state.
3Stress or pressure
If a restriction is used to increase fluid pressure within the downhole device, then fluid diversion activation is achieved, but the flow area is limited
Solution Approach 1:
The restriction is segmented into multiple separate restrictions positioned at different locations within the device. This segmentation allows each restriction to contribute to pressure buildup while collectively maintaining a larger effective flow area than a single restriction would allow, resolving the trade-off between pressure generation and flow capacity.
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 efficient and reliable fluid diversion with reduced operational complexity and increased flow area, minimizing the need for port alignment and reducing the risk of seal failures, while maintaining accurate pressure control.
Implementation Method 1
Fluid flow through a restriction within the downhole device creates an increase in fluid pressure within the downhole device
Implementation Method 2
The increased fluid pressure moves the plurality of pistons downward within the downhole device
Data Source
AI summary
A downhole device used to divert fluid flow out of a work string into an annulus. The downhole device is activated by the movement of a plurality of pistons within the downhole device. Fluid flow through a restriction of the downhole device creates an increase in fluid pressure causing the movement of the pistons. The pistons move a flow tube between various locations within the device. In one location, the flow tube prevents fluid flow to the annulus while in another location the flow tube allows fluid flow to be diverted into the annulus. The downhole device may include a locating sleeve having a continuous j-track allowing the flow tube to be selectively retained at the various locations within the downhole device. Fluid flow through the downhole is used to cycle the device between diverting fluid flow to the annulus and forcing fluid flow down the work string.