NMR TBP Determination for Hydrocarbon Fluids
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Solution Overview
Problem
Conventional methods for determining the true boiling point (TBP) of hydrocarbon fluid mixtures, such as crude oils, are either time-consuming and not suitable for wide field deployment or require expensive equipment, limiting their applicability for rapid and portable measurements.
Innovation Solution
Nuclear Magnetic Resonance (NMR) relaxation and diffusion measurements are used to determine the boiling point distribution of hydrocarbon fluids by analyzing translational diffusion and spin relaxation signals, allowing for the inference of molecular size distributions and subsequently the boiling point distribution, which can be correlated with molecular weight and chain length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional analytical distillation is used to determine TBP, then measurement precision is improved, but measurement time increases and deployment feasibility decreases
Solution Approach 1:
The patent replaces the mechanical/thermal distillation process with an NMR-based measurement system. Instead of physically separating components through heating and condensation, the system uses nuclear magnetic resonance signals to directly probe molecular properties and infer TBP distribution, eliminating the time-consuming distillation process while maintaining measurement accuracy
Solution Approach 2:
The patent changes the measurement parameters from direct thermal observation (distillation curves) to molecular-level NMR parameters (relaxation times T1 and T2, diffusion coefficients). By measuring these molecular parameters and correlating them with boiling point characteristics, the system achieves rapid TBP determination without actual heating or phase change
2Productivity
If gas chromatography is used to approximate TBP measurement, then measurement speed is improved, but measurement capability for full TBP range deteriorates
Solution Approach 1:
The NMR system is designed to handle the complete TBP range of crude oil components in a single measurement, unlike GC which requires multiple runs or cannot effectively measure heavy fractions. The NMR method universally detects all hydrocarbon components based on their molecular properties, providing full TBP distribution from light to heavy fractions simultaneously
Solution Approach 2:
The patent replaces the GC separation mechanism with NMR's direct molecular probing capability. Instead of separating components through chromatographic columns and detecting them sequentially, the NMR system simultaneously characterizes all components in the sample based on their relaxation and diffusion properties, enabling full TBP range measurement in one rapid analysis
3Measurement precision
If traditional TBP distillation equipment is deployed, then measurement accuracy is maintained, but device complexity and cost increase
Solution Approach 1:
The patent extracts the essential measurement function from the complex distillation apparatus. Instead of requiring complete distillation equipment with heating systems, condensers, and collection vessels, the invention uses only the NMR spectrometer to directly measure molecular parameters that correlate with TBP, eliminating unnecessary equipment while preserving measurement capability
Solution Approach 2:
The NMR system creates a virtual representation of the TBP distribution by measuring molecular properties and applying calibration relationships. Rather than physically performing distillation and collecting fractions, the system copies the essential information about boiling point distribution through non-invasive NMR measurements, achieving the same analytical goal with simpler equipment
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 provides a fast, portable, and cost-effective method for determining TBP distributions, agreeing well with traditional gas chromatography results, and enables online monitoring in oil production environments, significantly reducing measurement time compared to traditional methods.
Implementation Method 1
using a nuclear magnetic resonance (NMR) system, applying an (NMR) signal to the sample and measuring at least one of a resulting translational diffusion signal and a resulting spin relaxation signal
Implementation Method 2
measuring at least one of a resulting translational diffusion signal and a resulting spin relaxation signal
Implementation Method 3
measuring at least one of a resulting translational diffusion signal and a resulting spin relaxation signal
Data Source
AI summary
Nuclear magnetic resonance (NMR) relaxation and/or diffusion measurements are used to deduce fluid compositional information such as a chain-length distribution, which may then be used to predict the true boiling points (TBP) of a sample of a complex hydrocarbon fluid mixture, such as a crude oil. The NMR measurements may be considered a fast and portable proxy measurement in estimating fluid TBP distributions in lieu of distillation methods, or the simulated distillation by gas chromatography.