Viscosity Sensor Using Off-Resonant Decay for Well Logging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring viscosity in well logging systems are inefficient, particularly in drilling wells, as they struggle to accurately determine viscosity without interfering with ongoing density measurements and require lengthy ring-down times for fluid analysis.
Innovation Solution
A wireline well logging system using a sample tube modeled as a distributed mass and spring arrangement, where the sample tube is excited to resonate and the decay of vibrations is monitored to calculate viscosity, allowing for real-time measurement and minimizing interference with density measurements by adjusting the phase delay to tune vibrations slightly off the resonant frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sample tube is excited to resonate at its resonant frequency for viscosity measurement, then measurement accuracy is improved, but the ring-down time increases causing interference with ongoing density measurements
Solution Approach 1:
The system dynamically adjusts the excitation frequency away from the resonant frequency during the measurement process. By tuning the excitation frequency to be slightly off-resonant, the vibrations are damped more rapidly, reducing the ring-down time while still allowing accurate viscosity measurement through the decay characteristics of the vibrations.
Solution Approach 2:
The system changes the operating parameters by modifying the excitation frequency parameter. Instead of using the resonant frequency, the system uses a detuned frequency that reduces the Q-factor and accelerates vibration decay, thereby shortening the ring-down time while maintaining measurement capability through alternative signal processing.
2Measurement precision
If the sample tube vibrates at resonant frequency for viscosity measurement, then measurement accuracy is improved, but interference with density measurements increases
Solution Approach 1:
The system dynamically adjusts the excitation frequency to be off-resonant during the viscosity measurement process. This dynamic frequency adjustment reduces the amplitude of vibrations that could interfere with subsequent density measurements, allowing continuous or rapid sequential measurements without significant cross-interference.
Solution Approach 2:
The system rushes through the measurement process by using off-resonant excitation to quickly establish the vibration decay characteristics needed for viscosity measurement. This rapid measurement approach minimizes the time the sample tube remains in a high-vibration state that could interfere with density measurements.
3Measurement precision
If traditional viscosity measurement methods are used in well logging, then measurement capability is maintained, but operational efficiency decreases
Solution Approach 1:
The system enables continuous operation by allowing viscosity measurements to be taken during or immediately following density measurements without requiring the sample tube to come to complete rest. The off-resonant excitation method maintains measurement capability while reducing the time required for the tube to stop vibrating, thus improving operational efficiency in well logging operations.
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 accurate and efficient viscosity measurement in real-time, reducing ring-down time and avoiding interference with continuous density measurements, thus improving the operational efficiency of well logging systems.
Implementation Method 1
the sample tube is excited to resonate and the decay of vibrations is monitored to calculate viscosity
Implementation Method 2
the sample tube is excited to resonate and the decay of vibrations is monitored to calculate viscosity
Implementation Method 3
a sample tube modeled as a distributed mass and spring arrangement
Data Source
AI summary
A fluid is received into a sample tube. A processor causes an energy to be applied to the sample tube to induce vibration in the sample tube at a resonant frequency of the sample tube containing the fluid. The processor stops the supply of energy to the sample tube. The processor monitors an amplitude of the vibration of the sample tube as the amplitude of the vibrations diminish over a period of time. The processor uses the monitored amplitude to calculate an RF of the sample tube containing the fluid. The processor uses the calculated RF to calculate the viscosity of the fluid.