Resonant Set Point Changes for Wellbore Oscillation Control
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Solution Overview
Problem
Drilling systems in the oilfield/hydrocarbon industry face challenges with resonant oscillations during changes in operating states, such as drillstring rotation speed or pressure, leading to inefficiencies and potential equipment damage due to large amplitude oscillations that take a long time to dissipate.
Innovation Solution
Implementing a method to change set points in wellbore systems over a time-scale controlled by the dominant resonance period of the system, using a processor to determine the period of the dominant resonance and process a change profile that minimizes excitation of this resonance, thereby reducing oscillations and improving control over wellbore processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If set point changes are made quickly in a resonant system, then productivity is improved, but large amplitude oscillations are excited that take a long time to dissipate
Solution Approach 1:
The patent applies periodic action by changing the set point in a periodic manner that is synchronized with the natural period of the resonant system. Specifically, the set point is changed over a time period that is an integer multiple of the dominant resonance period, which allows the system to complete full oscillation cycles during the transition, thereby minimizing the excitation of resonant oscillations and reducing the time required for oscillations to dissipate.
Solution Approach 2:
The patent utilizes parameter changes by modifying the time scale of set point changes based on the resonant properties of the system. The control parameter (set point) is changed over a time period that is determined by the dominant resonance period of the system, transforming the approach from arbitrary or rapid changes to controlled changes that account for the system's dynamic characteristics.
2Productivity
If set point changes are made quickly in a resonant system, then productivity is improved, but equipment reliability deteriorates due to large amplitude oscillations
Solution Approach 1:
The patent applies periodic action by changing the set point in a periodic manner that is synchronized with the natural period of the resonant system. Specifically, the set point is changed over a time period that is an integer multiple of the dominant resonance period, which allows the system to complete full oscillation cycles during the transition, thereby minimizing the excitation of resonant oscillations and reducing the time required for oscillations to dissipate.
Solution Approach 2:
The patent utilizes parameter changes by modifying the time scale of set point changes based on the resonant properties of the system. The control parameter (set point) is changed over a time period that is determined by the dominant resonance period of the system, transforming the approach from arbitrary or rapid changes to controlled changes that account for the system's dynamic characteristics.
3Reliability
If set point changes are made slowly to avoid resonance, then equipment reliability is improved, but productivity deteriorates
Solution Approach 1:
The patent applies periodic action by changing the set point in a periodic manner that is synchronized with the natural period of the resonant system. Specifically, the set point is changed over a time period that is an integer multiple of the dominant resonance period, which allows the system to complete full oscillation cycles during the transition, thereby minimizing the excitation of resonant oscillations and reducing the time required for oscillations to dissipate.
Solution Approach 2:
The patent utilizes parameter changes by modifying the time scale of set point changes based on the resonant properties of the system. The control parameter (set point) is changed over a time period that is determined by the dominant resonance period of the system, transforming the approach from arbitrary or rapid changes to controlled changes that account for the system's dynamic characteristics.
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
This approach allows for controlled and efficient changes in wellbore system set points, reducing oscillations and enhancing the effectiveness of drilling operations by aligning change times with the system's resonant periods, thus mitigating adverse effects on equipment and process efficiency.
Implementation Method 1
changes in the set-point of a resonant system may be made over a time-scale which is controlled by the dominant resonance of the system
Data Source
AI summary
A method for changing a set point of a system where period of a dominant resonance of the system is determined, a change profile for the set point change is processed; a time period for the set point change based on the period of the dominant resonance in order to minimize excitation of the dominant resonance is also processed; and the set point change is actioned according to the processed change profile and the time period.