Characterization of crude oil by ultraviolet visible spectroscopy
AssigneeSaudi Arabian Oil Company
InventorsOmer Refa Koseoglu, Adnan Al-Hajji, Gordon Jamieson
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Abstract
A system and a method for calculating the cetane number, pour point, cloud point and aniline point of a gas oil fraction of crude oil from the density and ultraviolet visible spectroscopy of a sample of the crude oil.
Claims24
A system for determining indicative properties of a gas oil fraction of a crude oil, based upon ultraviolet visible spectroscopy data derived from a sample of the crude oil and the weight and density of the sample, the system comprising:
- a non-volatile memory device that stores calculation modules and data;
- a processor coupled to the memory;
- a first calculation module that calculates a crude oil ultraviolet visible index value for the gas oil fraction based on the sample's weight and the absorbance values of the spectroscopy data;
- a second calculation module that derives the cetane number for the gas oil fraction of the crude oil as a function of the ultraviolet visible index and density of the sample;
- a third calculation module that derives the pour point for the gas oil fraction of the crude oil as a function of the ultraviolet visible index and density of the sample;
- a fourth calculation module that derives the cloud point for the gas oil fraction of the crude oil as a function of the ultraviolet visible index and density of the sample;
- and
- a fifth calculation module that derives the aniline point for the gas oil fraction of the crude oil as a function of the ultraviolet visible index and density of the sample.
A method for operating a computer to determine indicative properties of a gas oil fraction of crude oil boiling in the range of 180-370° C. based upon a sample of the crude oil collected from an oil well, stabilizer, extractor, or distillation tower, the method comprising:
- weighing the sample;
- preparing said sample for ultraviolet visible spectroscopy analysis by diluting the sample with solvents;
- obtaining spectra data for the sample by an ultraviolet visible spectroscopy analysis in a wavelength range from 220-500 nm;
- entering into the computer the spectra data for the sample;
- calculating an ultraviolet visible index of the gas oil fraction based on the spectra data;
- calculating the cetane number for the gas oil fraction as a function of the ultraviolet visible index and density of the sample, and storing the calculated cetane number into a non-volatile memory associated with the computer;
- calculating the pour point for the gas oil fraction as a function of the ultraviolet visible index and density of the sample, and storing the calculated pour point into the non-volatile memory associated with the computer;
- calculating the cloud point for the gas oil fraction as a function of the ultraviolet visible index and density of the sample, and storing the calculated cloud point into the non-volatile memory associated with the computer;
- and
- calculating the aniline point for the gas oil fraction as a function of the ultraviolet visible index and density of the sample, and storing the calculated aniline point into the non-volatile memory associated with the computer.
A system for evaluating a crude oil sample and calculating an indicative property, the system comprising:
- an ultraviolet visible spectrophotometer;
- a non-volatile memory device that stores calculation modules and data, the data including density of the crude oil sample and spectroscopy data obtained from the ultraviolet visible spectrophotometer;
- a processor coupled to the non-volatile memory;
- a first calculation module that calculates a crude oil ultraviolet visible index value for the gas oil fraction based on the sample's weight and the absorbance values of the spectroscopy data;
- and
- a second calculation module that calculates the indicative property as a function of the ultraviolet visible index and the density of the sample.
A method for operating a computer to evaluate a crude oil sample and calculate an indicative property, the method comprising:
- weighing the sample;
- preparing said sample for ultraviolet visible spectroscopy analysis by diluting the sample with solvents;
- obtaining spectra data for the sample by an ultraviolet visible spectroscopy analysis in a wavelength range from 220-500 nm;
- entering into the computer the spectra data for the sample;
- calculating an ultraviolet visible index of the gas oil fraction based on the spectra data;
- and
- calculating the indicative property as a function of the ultraviolet visible index and density of the sample, and storing the calculated indicative property into a non-volatile memory associated with the computer.
Dependencies are inferred from the claim text.