NMR Hydrocarbon Fluid Transition Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current NMR techniques face challenges in accurately identifying transition characteristics in hydrocarbon fluids, such as asphaltene onset pressure, bubble point, and dew point, under varying pressures and temperatures, due to limitations in sensitivity and precision in detecting phase changes and molecular dynamics.
Innovation Solution
The method involves subjecting hydrocarbon fluids to different pressures or temperatures, conducting NMR tests to obtain data on parameters like T2 relaxation time and diffusion, and processing this data to identify discontinuities, which indicate transition characteristics using techniques like dual linear fitting and Bayesian change point detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional NMR techniques are used to measure hydrocarbon fluid properties, then basic relaxation times can be obtained, but sensitivity and precision in detecting phase changes and molecular dynamics are insufficient
Solution Approach 1:
The patent applies parameter changes by systematically varying pressure and temperature conditions during NMR measurements to detect transition characteristics. By changing physical parameters (pressure, temperature) and analyzing the response of NMR parameters (T1, T2, diffusion coefficients), the method enhances sensitivity in detecting phase changes and molecular dynamics transitions without requiring fundamental changes to the NMR measurement system.
2Measurement precision
If multiple NMR parameters are measured under varying conditions to identify transition characteristics, then measurement precision improves, but the complexity of data processing and analysis increases
Solution Approach 1:
The patent applies preliminary action by pre-processing NMR data through normalization and baseline correction before analyzing transition characteristics. The method establishes reference states at known conditions and prepares data structures that facilitate subsequent comparison and identification of transitions, reducing the complexity of final analysis while maintaining high precision in detecting bubble points, dew points, and asphaltene onset pressures.
Solution Approach 2:
The patent applies feedback by using the measured NMR parameters (T1, T2, diffusion coefficients) under varying pressure and temperature conditions to identify transition characteristics, which then inform the interpretation of fluid behavior. The analysis of how these parameters change with conditions provides feedback about molecular dynamics and phase transitions, enabling accurate identification of critical points while systematically processing the data.
3Measurement precision
If traditional methods are used to determine asphaltene onset pressure and bubble point, then basic fluid properties can be identified, but sensitivity in detecting molecular dynamics changes is limited
Solution Approach 1:
The patent applies continuity of useful action by conducting NMR measurements continuously across a range of pressure and temperature conditions rather than at discrete points. This continuous approach allows for capturing the evolution of T1, T2, and diffusion coefficients through transitions, enhancing sensitivity to molecular dynamics changes while efficiently utilizing measurement time by obtaining comprehensive data in a systematic sequence.
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 enables precise identification of transition characteristics by detecting significant changes in NMR signatures, providing more accurate and sensitive measurements of phase changes and molecular dynamics, thereby improving the determination of critical fluid properties like asphaltene onset pressure and bubble point.
Implementation Method 1
Nuclear magnetic resonance (NMR) is a useful tool in investigating the properties of a sample. More specifically, NMR tools are used in laboratories as well as in boreholes traversing earth formations in order to investigate the properties of fluids and rock samples.
Implementation Method 2
identifying one or more transition characteristics in a hydrocarbon fluid... subjecting the fluid to different pressures or temperatures... identifying a fluid transition characteristic of the substance by locating a discontinuity in the signature
Data Source
AI summary
Methods are provided for identifying one or more transition characteristics in a hydrocarbon fluid such as asphaltene onset pressure (AOP), bubble point or dew point. A transition characteristic is determined by subjecting the fluid to different pressures or temperatures, conducting NMR tests at the different pressures or temperatures to obtain signals, processing the signals to obtain values of a function of an NMR parameter as a function of pressure or temperature, and analyzing the values to find a discontinuity that identifies the transition characteristic. In embodiments, the NMR parameters may include at least one of a relaxation parameter such as T2 or a T1-T2 ratio, a diffusion parameter and an initial magnetization parameter. In embodiments, dual linear fitting, Bayesian change point detection algorithms, and instantaneous slope analysis may be utilized to analyze the values in order to find a discontinuity.