Dual-Action Hydraulic Anchor for Wellbore Sidetracking
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Solution Overview
Problem
Existing wellbore anchors have limited radial expansion capabilities and setting force, making them susceptible to movement during sidetrack drilling operations, and are prone to damage from shocks and irregularities in the wellbore, leading to insecure anchor placement and potential operational failures.
Innovation Solution
A dual-action hydraulically operable anchor system with opposing upper and lower hydraulic pistons and a floating mandrel, which applies additive forces through hydraulic and mechanical means to securely position a whipstock in the wellbore, including a Belleville spring stack for shock absorption and a split clamp for flexible movement, ensuring stable anchoring during wellbore departure and lateral drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional single-action hydraulic anchors are used, then the device complexity is low, but the setting force and radial expansion capability are limited, leading to anchor movement during sidetrack drilling
Solution Approach 1:
The anchor system is divided into two independent hydraulic pistons (upper and lower) that operate separately to provide additive setting forces. This segmentation allows each piston to contribute independently to the total setting force, resolving the contradiction by increasing force through structural division rather than requiring a single complex high-force mechanism
Solution Approach 2:
The patent combines hydraulic actuation with mechanical locking features (ratchet and pawl mechanism) to create a hybrid setting system. The hydraulic pistons provide the primary setting force while the mechanical latch provides supplemental locking, merging two different actuation methods to achieve superior anchor stability without proportionally increasing system complexity
2Reliability
If anchors with limited radial expansion capability are used, then the ease of operation is good, but the reliability of anchor placement is poor due to susceptibility to movement
Solution Approach 1:
The anchor system incorporates a dynamic radial expansion capability where the slips can expand radially outward under hydraulic pressure to engage the wellbore wall. This dynamic expansion allows the anchor to adapt to varying wellbore conditions and achieve reliable placement while maintaining operational simplicity through automated hydraulic actuation
Solution Approach 2:
The mechanical ratchet and pawl mechanism provides a feedback-based locking system that automatically engages when the hydraulic pistons apply setting force. This mechanical feedback ensures the anchor maintains its position even if hydraulic pressure fluctuates, improving reliability without requiring complex control systems
3Reliability
If anchors without shock absorption features are used, then the device complexity is low, but the reliability is poor due to damage from shocks and irregularities in the wellbore
Solution Approach 1:
The patent incorporates a shock-absorbing element (Belleville spring stack) that is pre-positioned to cushion impacts from wellbore irregularities. This beforehand cushioning protects critical components like the hydraulic pistons and slips from damage during anchor deployment and setting operations, improving reliability without requiring complex active protection systems
4Force
If dual-action hydraulic pistons with additive forces are used, then the setting force is extreme for secure engagement, but the device complexity increases
Solution Approach 1:
The patent uses hydraulic pistons actuated by fluid pressure to generate the extreme setting forces required for secure anchor engagement. The hydraulic system allows forces to be multiplied through fluid pressure transmission, achieving high setting forces without requiring proportionally complex mechanical advantage systems
Solution Approach 2:
The mechanical ratchet and pawl mechanism provides self-locking functionality that automatically engages when the hydraulic pistons apply force. This self-service feature maintains the anchor position without requiring continuous hydraulic pressure or complex active control systems, reducing the effective complexity of the high-force system
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 dual-action anchor system provides extreme force for secure engagement with the wellbore wall, absorbing shocks and maintaining anchor stability, thereby ensuring reliable wellbore departure and lateral drilling operations by applying concurrent hydraulic and mechanical forces for enhanced setting and stability.
Implementation Method 1
a Belleville spring stack for shock absorption
Implementation Method 2
upper piston and opposing lower piston that enable force slips outward
Data Source
AI summary
A dual-action hydraulically operable anchor includes a hydraulic anchor body for positioning a whipstock in a wellbore. A split clamp retains an upper sub and the hydraulic anchor body. A lower cap guides the hydraulic anchor within the wellbore. The floating mandrel transmits a hydraulic fluid into the fixed housing, transmitting compressive force from the upper hydraulic piston or from mechanical force applied to the whipstock above and adjoining the hydraulic anchor. The lower hydraulic piston operates along the floating mandrel using transmitted hydraulic fluid. A T-slot adapter and a slip move from a flush position along the fixed housing to an extended position along the fixed housing such that the slip firmly engages the wellbore to hold the hydraulic anchor and the whipstock in a fixed position for providing a path for lateral drilling outside the wellbore.