C-Ring Closure Seat for Downhole Tool Ball Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing downhole tools face issues with unreliable ball seat designs, such as collet fingers failing to seal properly, erosion, and complex mechanisms that can lead to tool failure and damage to the formation, when using fluid pressure to actuate components.
Innovation Solution
A downhole tool with a C-ring closure seat that uses a radially outward retainer to initially hold the C-ring in place, a seal for sealing with the ball, and a shear pin to release the C-ring for axial movement in response to predetermined fluid pressure, allowing controlled release of the closure member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If collet fingers are used as a ball seat to allow pressure buildup, then the ball can be sealed and tool components can be actuated, but the collet fingers may fail to seal properly and erode from wellbore fluids, causing tool failure
Solution Approach 1:
The patent removes the ball seat function from the collet fingers entirely. Instead, a separate C-ring closure seat is provided that the ball seals against, while the collet fingers solely perform their expanding/contracting function to hold or release the ball. This separation eliminates the erosion problem affecting the ball seat while maintaining the sealing capability.
Solution Approach 2:
The tool divides the ball seat function from the collet mechanism. The C-ring closure seat is a distinct component from the collet fingers, with each having specialized functions. The C-ring provides the sealing surface while the collet fingers provide the holding/release mechanism, creating functional segmentation that improves reliability.
2Reliability
If a rotating ball valve design is used with a small hole as the ball seat, then the ball can be sealed and pressure can be applied to rotate the ball for release, but the design becomes complicated with many parts that may cause failure
Solution Approach 1:
The patent eliminates the rotating ball valve mechanism entirely. Instead of using a rotating valve with a small hole, the design uses a stationary C-ring closure seat with a simple annular sealing surface. The ball seals against this stationary surface, and release is achieved through axial movement of the C-ring rather than rotation, dramatically simplifying the design.
Solution Approach 2:
Instead of rotating the ball valve to open a passage, the invention inverts the approach by using axial movement of the C-ring closure seat to release the ball. The ball remains stationary on the sealing surface, and the C-ring moves axially to allow ball passage, reversing the conventional rotational release mechanism.
3Reliability
If a yieldable ball seat is used that expands at certain pressures, then the ball can be released at preselected pressure, but quality control is difficult and the seat may not yield when intended, and high pressure may damage the tool or formation
Solution Approach 1:
The patent replaces the yieldable material expansion mechanism with a mechanical shear pin system. The C-ring is held in the compressed position by shear pins that break at a predetermined shear strength corresponding to the desired ball release pressure. This mechanical approach provides precise, controllable pressure release without the quality control issues of yieldable materials.
Solution Approach 2:
The invention changes the release mechanism from material property-based (yield strength of expandable material) to component property-based (shear strength of pins). By using pins with controlled shear strength, the release pressure parameter can be precisely determined and reproduced, eliminating the manufacturing precision problems associated with yieldable ball seats.
4Reliability
If a mechanically expanding ball seat is used that requires drill string manipulation to open, then the ball can be released, but the design is complicated and pressure equalization is required before mechanical manipulation
Solution Approach 1:
The patent replaces the mechanical drill string manipulation system with a fluid pressure-actuated system. The C-ring is automatically released when fluid pressure exceeds the shear strength of the pins, eliminating the need for complex mechanical manipulation of the drill string. The release is achieved purely through hydraulic pressure buildup.
Solution Approach 2:
The ball release mechanism is self-actuating through fluid pressure. The increasing fluid pressure automatically shears the pins and releases the C-ring without requiring external mechanical intervention or pressure equalization procedures. The system serves itself by using the applied pressure to trigger its own release mechanism.
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
The C-ring closure seat design provides reliable and controlled operation of downhole tools, ensuring the ball or closure member is released at the appropriate pressure, reducing the risk of tool failure and formation damage, and allowing for efficient completion of desired operations.
Implementation Method 1
a shear pin to release the C-ring for axial movement in response to a predetermined fluid pressure
Data Source
AI summary
A downhole tool (100) includes a closure seat (116, 176) for seating with a closure, such as a, ball. Shear pins or other connectors temporarily limit axia movement of the closure seat which is initially housed within a restricte diameter portion of the central throughbore in the tool body. The closure sea may be lowered to engage a stop (108, 157), thereby positioning the seat withi an enlarged diameter bore portion of the tool and allowing radial expansion of closure seat to release the ball.