CHARACTERIZATION OF CRUDE OIL BY NMR SPECTROSCOPY
A system and a method for applying 13 C or 1 H NMR spectroscopy to a sample of crude oil in order to calculate the cetane number, pour point, cloud point, aniline point and octane number of a gas oil fraction of the crude oil.
1 . A system for evaluating a crude oil sample and calculating indicative properties of a naphtha or gas oil fraction of the crude oil sample without first distilling the said naphtha or gas oil fraction, the system comprising:
an NMR spectroscope;
a non-volatile memory device that stores calculation modules and data;
a processor coupled to the non-volatile memory;
a first calculation module that calculates the cetane number for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample;
a second calculation module that calculates the pour point for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample;
a third calculation module that calculates the cloud point for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample;
a fourth calculation module that calculates the aniline point for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample; and
a fifth calculation module that calculates the octane number for the naphtha fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample.
2 . The system of claim 1 in which the NMR spectroscopy employs 1 H active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
3 . The system of claim 1 in which the NMR spectroscopy employs 13 C active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
4 . The system of claim 1 wherein the gas oil boils in the nominal range 180-370° C.
5 . The system of claim 1 wherein the naphtha boils in the nominal range 36-180° C.
6 . A system for evaluating a crude oil sample and calculating indicative properties of a naphtha or gas oil fraction of the crude oil sample without first distilling the said naphtha or gas oil fraction, the system comprising:
an NMR spectroscope;
a non-volatile memory device that stores calculation modules and data;
a processor coupled to the non-volatile memory;
a first calculation module that calculates the cetane number for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample;
a second calculation module that calculates the pour point for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample;
a third calculation module that calculates the cloud point for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample;
a fourth calculation module that calculates the aniline point for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample; and
a fifth calculation module that calculates the octane number for the naphtha fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample.
7 . The system of claim 6 in which the NMR spectroscopy employs 1 H active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
8 . The system of claim 6 in which the NMR spectroscopy employs 13 C active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
9 . The system of claim 6 wherein the gas oil boils in the nominal range 180-370° C.
10 . The system of claim 6 wherein the naphtha boils in the nominal range 36-180° C.
11 . A method for evaluating a crude oil sample to determine indicative properties of a naphtha or gas oil fraction of the crude oil sample sample without first distilling the said naphtha or gas oil fraction, the method comprising:
subjecting said sample to NMR analysis;
calculating the cetane number for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample;
calculating the pour point for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample;
calculating the cloud point for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample;
calculating the aniline point for the gas oil fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample; and
calculating the octane number for the naphtha fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample.
12 . The method of claim 11 in which the NMR spectroscopy employs 1 H active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
13 . The method of claim 11 in which the NMR spectroscopy employs 13 C active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
14 . The method of claim 11 wherein the gas oil boils in the nominal range 180-370° C.
15 . The method of claim 11 wherein the naphtha boils in the nominal range 36-180° C.
16 . A method for evaluating a crude oil sample to determine indicative properties of a naphtha or gas oil fraction of the crude oil sample sample without first distilling the said naphtha or gas oil fraction, the method comprising:
determining density of the crude oil sample;
subjecting said crude oil sample to NMR analysis;
calculating the cetane number for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample;
calculating the pour point for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample;
calculating the cloud point for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample;
calculating the aniline point for the gas oil fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample; and
calculating the octane number for the naphtha fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample.
17 . The method of claim 16 in which the NMR spectroscopy employs 1 H active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
18 . The method of claim 16 in which the NMR spectroscopy employs 13 C active nuclei to determine the aromatic, naphthenic and paraffinic carbon contents.
19 . The method of claim 16 wherein the gas oil boils in the nominal range 180-370° C.
20 . The method of claim 16 wherein the naphtha boils in the nominal range 36-180° C.
21 . A system for evaluating a crude oil sample and calculating an indicative property of a naphtha or gas oil fraction of the crude oil without first distilling the said naphtha or gas oil fraction, the system comprising:
an NMR spectroscope;
a non-volatile memory device that stores calculation modules and data;
a processor coupled to the non-volatile memory;
a calculation module that calculates the indicative property for the gas oil or naphtha fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample.
22 . The system of claim 21 , wherein the indicative property is the cetane number.
23 . The system of claim 21 , wherein the indicative property is the pour point.
24 . The system of claim 21 , wherein the indicative property is the cloud point.
25 . The system of claim 21 , wherein the indicative property is the aniline point.
26 . The system of claim 21 , wherein the indicative property is the octane number.
27 . A system for evaluating a crude oil sample and calculating an indicative property of a naphtha or gas oil fraction of crude oil without first distilling the said naphtha or gas oil fraction, the system comprising:
an NMR spectroscope;
a non-volatile memory device that stores calculation modules and data;
a processor coupled to the memory;
a calculation module that calculates the indicative property for the gas oil or naphtha fraction of the crude oil as a function of density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by NMR spectroscopy of the crude oil sample.
28 . The system of claim 27 , wherein the indicative property is the cetane number.
29 . The system of claim 27 , wherein the indicative property is the pour point.
30 . The system of claim 27 , wherein the indicative property is the cloud point.
31 . The system of claim 27 , wherein the indicative property is the aniline point.
32 . The system of claim 27 , wherein the indicative property is the octane number.
33 . A method for evaluating a crude oil sample to determine an indicative property of a naphtha or gas oil fraction of the crude oil sample without first distilling the said naphtha or gas oil fraction, the method comprising:
subjecting said sample to NMR analysis;
calculating the indicative property for the gas oil or naphtha fraction of the crude oil as a function of aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample.
34 . The method of claim 33 , wherein the indicative property is the cetane number.
35 . The method of claim 33 , wherein the indicative property is the pour point.
36 . The method of claim 33 , wherein the indicative property is the cloud point.
37 . The method of claim 33 , wherein the indicative property is the aniline point.
38 . The method of claim 33 , wherein the indicative property is the octane number.
39 . A method for evaluating a crude oil sample to determine an indicative property of a naphtha or gas oil fraction of the crude oil sample without first distilling the said naphtha or gas oil fraction, the method comprising:
determining density of the crude oil sample;
subjecting said sample to NMR analysis;
calculating the indicative property for the gas oil or naphtha fraction of the crude oil as a function of the density of the crude oil sample and aromatic, naphthenic, and paraffinic carbon contents determined by the NMR analysis of the crude oil sample.
40 . The method of claim 39 , wherein the indicative property is the cetane number.
41 . The method of claim 39 , wherein the indicative property is the pour point.
42 . The method of claim 39 , wherein the indicative property is the cloud point.
43 . The method of claim 39 , wherein the indicative property is the aniline point.
44 . The method of claim 39 , wherein the indicative property is the octane number.