Drilling Controller for Stick-Slip Mitigation
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Solution Overview
Problem
Current drilling technologies face challenges with stick-slip phenomena, where drilling apparatuses become stuck in the borehole wall, leading to premature wear, reduced drilling efficiency, and delayed operations due to uncontrolled torque and vibrations across multiple frequencies.
Innovation Solution
A drilling system that employs a controller with a wider bandwidth to mitigate stick-slip vibrations by manipulating top drive torque and drill string speed, using a controller design that absorbs torsional vibration waves at multiple frequencies and maintains set-point tracking, thereby preventing premature wear and improving drilling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drilling control methods are used, then the drilling operation can proceed with standard equipment, but stick-slip vibrations occur causing premature wear and reduced drilling efficiency
Solution Approach 1:
The control system continuously monitors drill string speed and torque, and adjusts top drive torque in real-time based on feedback signals. This closed-loop feedback mechanism detects stick-slip vibrations and automatically counteracts them by modulating the torque applied to the drill string, thereby protecting downhole components from premature wear while maintaining drilling efficiency
Solution Approach 2:
The system dynamically changes operating parameters including top drive torque magnitude and drill string rotational speed to eliminate stick-slip vibrations. By adjusting these parameters in real-time based on detected vibration conditions, the system optimizes both component lifespan and drilling productivity
2Power
If top drive torque is increased to maintain drill string rotation, then drilling power is improved, but stick-slip vibrations are exacerbated causing more severe wear and operational delays
Solution Approach 1:
The control system applies periodic modulation to the top drive torque at frequencies that counteract the stick-slip vibrations. By using periodic control actions synchronized with the vibration frequency, the system can reduce harmful vibrations while maintaining effective drilling power through constructive interference that stabilizes drill string rotation
Solution Approach 2:
The system uses controlled mechanical vibrations through the top drive torque modulation to counteract harmful stick-slip vibrations. By introducing beneficial vibrations at specific frequencies and amplitudes, the system reduces the magnitude of harmful stick-slip events while preserving drilling power
3Device complexity
If a narrow bandwidth controller is used, then the control system is simpler to implement, but it cannot effectively mitigate stick-slip vibrations across multiple frequencies
Solution Approach 1:
The controller is designed with wide bandwidth capability to handle multiple vibration frequencies simultaneously. This universal controller can mitigate stick-slip vibrations across a broad frequency range, making the system effective under varying drilling conditions while maintaining reasonable complexity through modular control architecture
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 system effectively reduces stick-slip induced vibrations across a wide frequency range, extending the lifespan of downhole components and enhancing drilling quality by controlling torque and rotation parameters.
Implementation Method 1
drilling apparatuses become stuck in the borehole wall, causing the drill string to 'stick.' When the drilling apparatus 'sticks,' the rotational movement of the drill string is either stopped or severely decreased. Torque is still imparted to the drill string at the surface, despite the drilling apparatus being stuck, causing the drill string to twist. Once the torque applied to the drill string overcomes the force of static friction on the drilling apparatus, the drill string 'slips' or releases from the borehole wall.
Data Source
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AI summary
A method and system for dampening a stick-slip vibration. The method may comprise determining at least one frequency of a stick-slip vibration; determining mechanical properties of the drilling system; producing a torque signal from a controller having at least a second order; controlling a rotational speed of a top drive from the torque signal produced by the controller; and damping stick-slip vibration of the drilling system. The system may further comprise a drill string and a bottom hole assembly may be connected to the drill string. A drill bit may be connected to the bottom hole assembly and an information handling system may be connected to the drilling system.