Dissolvable Ball Actuator for Circulating Sub Control
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Solution Overview
Problem
Existing circulating sub apparatuses in drill pipes face challenges in managing lost circulation materials (LCM) slurry, as particulates or fibrous materials can clog downhole tools, and existing solutions lack efficient control over activation and deactivation processes.
Innovation Solution
A method and system utilizing a ball that is insoluble in downhole fluid but soluble in a different solvent, where the ball activates the circulating sub by seating on an actuator, and deactivates by dissolving in the solvent, allowing for controlled bypass flow paths for LCM slurry and efficient tool protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ball is used to activate the circulating sub by seating on an actuator, then the port can be opened to enable bypass flow path, but the ball cannot be easily removed to close the port without interrupting drilling activities
Solution Approach 1:
The ball's solubility parameter is changed by introducing a solvent that dissolves the ball material, enabling deactivation of the circulating sub without mechanical removal. This chemical parameter change allows the port to close automatically as the ball dissolves, eliminating the need to interrupt drilling activities for ball retrieval.
Solution Approach 2:
The mechanical system of physically removing the ball to close the port is replaced with a chemical dissolution process. The solvent chemically breaks down the ball material, causing it to disintegrate and close the port automatically, substituting mechanical retrieval with chemical degradation.
2Productivity
If a ball collector is used to store deactivated balls, then multiple activation-deactivation cycles can be performed, but the ball collector capacity is limited and requires periodic emptying
Solution Approach 1:
The ball is designed as a disposable component that dissolves completely after a single activation cycle. Instead of collecting and reusing balls, the system uses new dissolvable balls for each activation, eliminating the need for ball collector emptying operations and simplifying the overall system management.
Solution Approach 2:
The ball material is extracted or dissolved by the solvent, removing the need for a physical ball collector entirely. The dissolution process extracts the ball material into solution, allowing indefinite cycles without collector capacity limitations or emptying requirements.
3Adaptability or versatility
If particulates or fibrous materials in LCM slurry are allowed to flow through downhole tools, then lost circulation can be managed, but the tools become clogged
Solution Approach 1:
The circulating sub with its controllable port acts as an intermediary device between the LCM slurry and the downhole tools. By opening the port, it provides an alternative bypass path for particulates and fibrous materials to exit the drill pipe, preventing them from entering and clogging the downhole tools while maintaining the ability to pump LCM slurry.
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 controlled activation and deactivation of the circulating sub, preventing tool clogging and allowing for multiple cycles without interrupting drilling activities, as the ball collector can hold more balls due to the core-shell design, and no collector is needed for entirely soluble balls, enabling indefinite activation-deactivation cycles.
Implementation Method 1
a solubility of the ball in the solvent is greater than a solubility of the ball in the downhole fluid
Data Source
AI summary
A method for operating a circulating sub in a well includes opening a port of the circulating sub, including: dropping a ball into a drill pipe containing a downhole fluid; and seating the ball on an actuator slidably disposed concentrically within the drill pipe, in which seating the ball on the actuator causes motion of the actuator relative to the drill pipe to open a port defined in a wall of the drill pipe. The method includes closing the port of the circulating sub, including: introducing a solvent different from the downhole fluid into the drill pipe, in which a solubility of the ball in the solvent is greater than a solubility of the ball in the downhole fluid; and degrading the ball in the solvent, in which the degrading of the ball causes motion of the actuator relative to the drill pipe to close the port.