Whipstock Section Separation for Contingency Mill Release
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Solution Overview
Problem
Existing mechanisms for releasing mills from whipstocks in well drilling operations are prone to premature or inadvertent shearing, especially when encountering obstructions or wellbore direction changes, leading to inefficiencies and increased operational costs.
Innovation Solution
A bottom hole assembly with a whipstock and mill configuration that includes a retractable pin and a weakened section between the whipstock's opening and upper end, allowing for separation via applied force, supplemented by a hydraulic release mechanism and contingency release feature to ensure reliable detachment even if the hydraulic mechanism fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a shearable bolt is used to releasably secure the whipstock to the mill, then the mill can be released from the whipstock, but the bolt may be inadvertently or prematurely sheared due to obstructions or wellbore direction changes
Solution Approach 1:
The whipstock is divided into multiple sections that can separate from each other. The first section remains attached to the mill while the second section separates, allowing the mill to be released without shearing a bolt. This segmentation enables controlled separation that prevents premature failure.
Solution Approach 2:
The connection between whipstock sections transitions from a static shearable bolt to a dynamic separation mechanism. The sections can remain connected during normal operations but can separate when force is applied, providing both security during conveyance and reliable release when needed.
2Productivity
If the whipstock is releasably attached to the mill during conveyance, then the mill can be released at desired position, but additional trips may be required if release fails
Solution Approach 1:
The whipstock sections are pre-configured to separate upon application of force in a predetermined direction. This preliminary arrangement ensures that if the first release mechanism fails, the sections can still separate, eliminating the need for additional trips and saving time.
Solution Approach 2:
The design includes a backup separation mechanism that acts as a safety cushion. If the primary release method fails, the predetermined separation path prevents catastrophic failure and avoids the need for costly additional trips, thereby improving productivity.
3Strength
If a retractable pin is used to secure the whipstock to the mill, then the connection can be maintained during conveyance, but the pin may fail to retract properly under certain conditions
Solution Approach 1:
Instead of relying solely on the retractable pin, the whipstock is segmented into sections that can separate independently. This provides a backup release mechanism that does not depend on pin retraction, ensuring reliable mill release even if the pin fails to retract properly.
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 release of the mill from the whipstock, facilitating continued milling operations or retrieval, reducing the need for additional trips and enhancing operational efficiency and safety.
Implementation Method 1
a section of the whipstock is separable from the whipstock in response to a force applied to the mill
Data Source
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AI summary
A bottom hole assembly can include a mill and a whipstock having an upper end and an opening. A retractable pin extends from the mill into the opening. A section of the whipstock is separable from the whipstock in response to a force applied to the mill. The section is positioned between the opening and the upper end. A method can include positioning a bottom hole assembly in a well, the bottom hole assembly including a whipstock releasably secured to a mill, and then releasing the mill from the whipstock by separating a section of the whipstock from a remainder of the whipstock. Another method can include conveying a bottom hole assembly into a well, setting an anchor, then applying pressure to a hydraulic release mechanism, and then applying a force to the mill, thereby separating a section of the whipstock from a remainder of the whipstock.