CHARACTERIZATION OF CRUDE OIL BY NMR SPECTROSCOPY

Abstract

A system and a method for applying .sup.13C or .sup.1H NMR spectroscopy to a sample of oil in order to calculate and assign an indicative property such as cetane number, pour point, cloud point, aniline point and/or octane number of a gas oil or naphtha fraction of the crude oil.

Claims

1. A system for assigning an indicative property to a fraction of an oil sample based upon nuclear magnetic resonance (NMR) spectroscopy data, the system comprising: a non-volatile memory device that stores calculation modules and data, the data including NMR spectroscopy data indicative of aromatic, naphthenic, paraffinic carbon content of the oil sample; a processor coupled to the memory; and a calculation module that calculates and assigns the indicative property of a fraction of the oil sample as a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample.

2. A system for assigning an indicative property to a fraction of an oil sample comprising: a nuclear magnetic resonance (NMR) spectrometer that outputs NMR spectroscopy data; a non-volatile memory device that stores calculation modules and data, the data including outputted NMR spectroscopy data indicative of aromatic, naphthenic, paraffinic carbon content of the oil sample; a processor coupled to the memory; and a calculation module that calculates and assigns the indicative property of a fraction of the oil sample as a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample.

3. The system of claim 1 wherein the calculation module calculates and assigns the indicative property of a fraction of the oil sample as a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample and the density of the oil sample.

4. A method for operating a computer to assign an indicative property to a fraction of an oil sample based upon nuclear magnetic resonance (NMR) spectroscopy data, the method comprising: entering into the computer NMR spectroscopy data indicative of the aromatic, naphthenic, paraffinic carbon content of the oil sample; calculating and assigning the indicative property of a fraction of the oil sample as a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample.

5. A method for assigning an indicative property to a fraction of an oil sample comprising: preparing the sample for nuclear magnetic resonance (NMR) spectroscopy; obtaining NMR spectroscopy data indicative of the aromatic, naphthenic, paraffinic carbon content from NMR spectroscopy of the prepared sample; entering into a computer the obtained NMR spectroscopy data; calculating and assigning the indicative property of a fraction of the oil sample as a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample.

6. The method of claim 4 wherein calculating and assigning the indicative property of a fraction of the oil sample is a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample and the density of the oil sample.

7. The method of claim 4 wherein the oil sample is crude oil.

8. The method of claim 4 the oil sample is obtained from an oil well, stabilizer, extractor, or distillation tower.

9. The method of claim 4 wherein the indicative property is a cetane number.

10. The method of claim 4 wherein the indicative property is a pour point.

11. The method of claim 4 wherein the indicative property is a cloud point.

12. The method of claim 4 wherein the indicative property is an aniline point.

13. The method of claim 4 wherein the indicative property is an octane number.

14. The method of claim 4 wherein plural indicative properties are calculated including at least two indicative properties selected from the group consisting of cetane number, pour point, cloud point, aniline point and octane number.

15. The method of claim 5 wherein NMR spectroscopy employs .sup.1H active nuclei to derive the aromatic, naphthenic and paraffinic carbon contents.

16. The method of claim 5 wherein NMR spectroscopy employs .sup.13C active nuclei to derive the aromatic, naphthenic and paraffinic carbon contents.

17. The system or method as in claim 16 wherein the indicative property is an octane number.

18. The method of claim 4 wherein the indicative property is of a gas oil fraction boiling in the nominal range 180-370° C.

19. The method of claim 4 wherein the indicative property is of a naphtha fraction boiling in the nominal range 36-180° C.

20. The system of claim 2 wherein the calculation module calculates and assigns the indicative property of a fraction of the oil sample as a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample and the density of the oil sample.

21. The method of claim 5 wherein calculating and assigning the indicative property of a fraction of the oil sample is a function of the aromatic, naphthenic, paraffinic carbon content of the oil sample and the density of the oil sample.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further advantages and features of the present invention will become apparent from the following detailed description of the invention when considered with reference to the accompanying drawings, in which:

[0023] FIG. 1 is a graphic plot of .sup.13C NMR data for the oils in a crude oil sample solution prepared as described below;

[0024] FIG. 2 is a process flow diagram of steps carried out to establish a value for indicative properties of a naphtha or gas oil fraction, using the system and method herein; and

[0025] FIG. 3 is a block diagram of a component of a system for implementing the invention, according to one embodiment of the present invention.

DETAILED DESCRIPTION OF INVENTION

[0026] A system and method is provided for determining one or more indicative properties of a hydrocarbon sample. Indicative properties (e.g., cetane number, pour point, cloud point and aniline point) of a gas oil fraction in crude oil samples are assigned as a function of data obtained from NMR data of a crude oil sample, and in certain embodiments also the density of the crude oil sample.

[0027] The correlations provide information about gas oil and/or naphtha indicative properties without fractionation/distillation (crude oil assays) and will help producers, refiners, and marketers to benchmark the oil quality and, as a result, valuate the oils without performing the customary extensive and time-consuming crude oil assays. The currently used crude oil assay method is costly in terms of money and time. It costs about $50,000 US and takes two months to complete one assay. With the method and system herein, the crude oil can be classified as a function of NMR data, and thus decisions can be made for purchasing and/or processing.

[0028] The systems and methods are applicable for naturally occurring hydrocarbons derived from crude oils, bitumens, heavy oils, shale oils and from refinery process units including hydrotreating, hydroprocessing, fluid catalytic cracking, coking, and visbreaking or coal liquefaction. Samples can be obtained from various sources, including an oil well, stabilizer, extractor, or distillation tower.

[0029] In the system and method herein, spectra are obtained by a suitable known or to be developed nuclear magnetic resonance spectrometer. Nuclear magnetic resonance (NMR) is a property that magnetic nuclei have under a magnetic field and applied electromagnetic (EM) pulse or pulses, which causes the nuclei to absorb energy from the EM pulse and radiate this energy back out. The energy radiated back out is at a specific resonance frequency which depends on the strength of the magnetic field and other factors. This allows the observation of specific quantum mechanical magnetic properties of an atomic nucleus.

[0030] All stable isotopes that contain an odd number of protons and/or of neutrons have an intrinsic magnetic moment and angular momentum, in other words a nonzero spin, while all nuclides with even numbers of both have spin 0. The most commonly studied nuclei are .sup.1H (the most NMR-sensitive isotope after the radioactive .sup.3H) and .sup.13C, although nuclei from isotopes of many other elements (e.g. .sup.2H, .sup.10B, .sup.11B, .sup.14N, .sup.15N, .sup.17O, .sup.19F, .sup.23Na, .sup.29Si, .sup.31P, .sup.35Cl, .sup.113Cd, .sup.129Xe, .sup.195Pt) are studied by high-field NMR spectroscopy as well.

[0031] NMR is a technique for determining the structure of organic compounds. NMR is non-destructive, and with modern instruments good data can be obtained from samples weighing less than a milligram. When a sample is placed in a magnetic field, NMR active nuclei (such as .sup.1H or .sup.13C) absorb at a frequency characteristic of the isotope. The resonant frequency, energy of the absorption and the intensity of the signal are proportional to the strength of the magnetic field. For example, in a 21 tesla magnetic field, protons resonate at 900 MHz. It is common to refer to a 21 T magnet as a 900 MHz magnet, although different nuclei resonate at a different frequency at this field strength.

[0032] FIG. 2 shows a process flowchart of steps in a method according to one embodiment herein that occur after NMR spectroscopy is completed and the results are tabulated. In step 210, the cetane number is calculated. In step 220, the pour point is calculated. In step 230, the cloud point is calculated. In step 240, the aniline point is calculated. In step 250, the octane number is calculated. While shown sequentially in FIG. 2, the steps can be performed parallel or in any order. In certain embodiments, only one or more or steps 210, 220, 230, 240, 250 are carried out.

[0033] In a first embodiment when the only input is a .sup.13C NMR spectra of crude oils, one or more indicative properties (e.g., the cetane number, pour point, cloud point, aniline point and octane number) of a gas oil fraction, e.g., boiling in the range of 150-400° C. and in certain embodiments in the range of 180-370° C., are assigned as a function of the aromatic, naphthenic and paraffinic carbon content determined by .sup.13C NMR spectra. That is,

Indicative Property=f(.sup.13C NMR Composition.sub.crude oil)  (1);

[0034] Equations (2) through (6) are detailed examples of this relationship.

Cetane Number (CET)=X1.sub.CET*C.sub.N+X2.sub.CET*C.sub.P+X3.sub.CET*C.sub.A+X4.sub.CET*C.sub.N.sup.2+X5.sub.CET*C.sub.P.sup.2+X6.sub.CET*C.sub.A.sup.2  (2);

Pour Point (PP)=X1.sub.PP*C.sub.N+X2.sub.PP*C.sub.P+X3.sub.PP*C.sub.A+X4.sub.PP*C.sub.N.sup.2+X5.sub.PP*C.sub.P.sup.2+X6.sub.PP*C.sub.A.sup.2  (3);

Cloud Point (CP)=X1.sub.CP*C.sub.N+X2.sub.CP*C.sub.P+X3.sub.CP*C.sub.A+X4.sub.CP*C.sub.N.sup.2+X5.sub.CP*C.sub.P.sup.2+X6.sub.CP*C.sub.A.sup.2  (4);

Aniline Point (AP)=X1.sub.AP*C.sub.N+X2.sub.AP*C.sub.P+X3.sub.AP*C.sub.A+X4.sub.AP*C.sub.N.sup.2+X5.sub.AP*C.sub.P.sup.2+X6.sub.AP*C.sub.A.sup.2  (5);

Octane Number (RON)=X1.sub.RON*C.sub.N+X2.sub.RON*C.sub.P+X3.sub.RON*C.sub.A+X4.sub.RON*C.sub.N.sup.2+X5.sub.RON*C.sub.P.sup.2+X6.sub.RON*C.sub.A.sup.2  (6);

[0035] where:

[0036] C.sub.N=CH.sub.3 protons of alkyl chains γ or further from aromatic ring or CH.sub.3 of saturated compounds (HSCH3);

[0037] C.sub.P=CH.sub.2 & CH protons of alkyl chains β or further to ring and CH.sub.3 protons β to the ring (HSβ+γ);

[0038] C.sub.A=Aromatic H; and

[0039] X1.sub.CET-X6.sub.CET, X1.sub.PP-X6.sub.PP, X1.sub.CP-X6.sub.CP, X1.sub.AP-X6.sub.AP, and X1.sub.RON-X6.sub.RON are constants.

[0040] In a second embodiment when density is considered in addition to a .sup.13C NMR spectra of crude oils, the indicative properties (e.g., the cetane number, pour point, cloud point, aniline point and octane number) of a gas oil fraction, e.g., boiling in the range of 150-400° C. and in certain embodiments in the range of 180-370° C., are assigned as a function of the whole crude oil density and aromatic, naphthenic and paraffinic carbon content determined by .sup.13C NMR spectra. That is,

Indicative Property=f(density.sub.crude oil,.sup.13C NMR Composition.sub.crude oil)  (7);

[0041] Equations (8) through (12) are detailed examples of this relationship.

Cetane Number (CET)=X1.sub.CET*DEN+X2.sub.CET*C.sub.N+X3.sub.CET*C.sub.P+X4.sub.CET*C.sub.A+X5.sub.CET*C.sub.N.sup.2+X6.sub.CET*C.sub.P.sup.2+X7.sub.CET*C.sub.A.sup.2  (8);

Pour Point (PP)=X1.sub.PP*DEN+X2.sub.PP*C.sub.N+X3.sub.PP*C.sub.P+X4.sub.PP*C.sub.A+X5.sub.PP*C.sub.N.sup.2+X6.sub.PP*C.sub.P.sup.2+X7.sub.PP*C.sub.A.sup.2  (9);

Cloud Point (CP)=X1.sub.CP*DEN+X2.sub.CP*C.sub.N+X3.sub.CP*C.sub.P+X4.sub.CP*C.sub.A+X5.sub.CP*C.sub.N.sup.2+X6.sub.CP*C.sub.P.sup.2+X7.sub.CP*C.sub.A.sup.2  (10);

Aniline Point (AP)=X1.sub.AP*DEN+X2.sub.AP*C.sub.N+X3.sub.AP*C.sub.P+X4.sub.AP*C.sub.A+X5.sub.AP*C.sub.N.sup.2+X6.sub.AP*C.sub.P.sup.2+X7.sub.AP*C.sub.A.sup.2  (11);

Octane Number (RON)=X1.sub.RON*DEN+X2.sub.RON*C.sub.N+X3.sub.RON*C.sub.P+X4.sub.RON*C.sub.A+X5.sub.RON*C.sub.N.sup.2+X6.sub.RON*C.sub.P.sup.2+X7.sub.RON*C.sub.A.sup.2  (12);

[0042] where

[0043] C.sub.N, C.sub.P and C.sub.A are as defined before,

[0044] DEN=density of the samples; and

[0045] X1.sub.CET-X7.sub.CET, X1.sub.PP-X7.sub.PP, X1.sub.CP-X7.sub.CP, X1.sub.AP-X7.sub.AP, and X1.sub.RON-X7.sub.RON are constants.

[0046] In a third embodiment when the only input is a .sup.1H NMR spectra of crude oils, the indicative properties (e.g., the cetane number, pour point, cloud point, aniline point and octane number) of a gas oil fraction, e.g., boiling in the range of 150-400° C. and in certain embodiments in the range of 180-370° C., are assigned as a function of the aromatic, naphthenic and paraffinic carbon content determined by .sup.1H NMR spectra. That is,

Indicative Property=f(.sup.1H NMR Composition.sub.crude oil)  (13);

[0047] Equations (2) through (6) can be applied as detailed examples of this relationship, where C.sub.N, C.sub.P, and C.sub.A are as defined before, and X1.sub.CET-X6.sub.CET, X1.sub.PP-X6.sub.PP, X1.sub.CP-X6.sub.CP, X1.sub.AP-X6.sub.AP, and X1.sub.RON-X6.sub.RON are constants.

[0048] In a fourth embodiment when density is considered in addition to a .sup.1H NMR spectra of crude oils, the indicative properties (e.g., the cetane number, pour point, cloud point, aniline point and octane number) a gas oil fraction, e.g., boiling in the range of 150-400° C. and in certain embodiments in the range of 180-370° C., are assigned as a function of the whole crude oil density and aromatic, naphthenic and paraffinic carbon content determined by .sup.1H NMR spectra. That is,

Indicative Property=f(density.sub.crude oil,.sup.1H NMR Composition.sub.crude oil)  (14);

[0049] Equations (8) through (12) can be applied as detailed examples of this relationship, where C.sub.N, C.sub.P and C.sub.A and DEN are as defined before, and X1.sub.CET-X7.sub.CET, X1.sub.PP-X7.sub.PP, X1.sub.CP-X7.sub.CP, X1.sub.AP-X7.sub.AP, and X1.sub.RON-X7.sub.RON are constants.

[0050] An exemplary block diagram of a computer system 300 by which indicative property calculation modules can be implemented is shown in FIG. 3. Computer system 300 includes a processor 310, such as a central processing unit, an input/output interface 320 and support circuitry 330. In certain embodiments, where the computer 300 requires direct human interaction, a display 340 and an input device 350 such as a keyboard, mouse or pointer are also provided. The display 340, input device 350, processor 310, input/output interface 320 and support circuitry 330 are shown connected to a bus 360 which also connects to a memory unit 370. Memory 370 includes program storage memory 380 and data storage memory 390. Note that while computer 300 is depicted with the direct human interface components of display 340 and input device 350, programming of modules and importation and exportation of data can also be accomplished over the interface 320, for instance, where the computer 300 is connected to a network and the programming and display operations occur on another associated computer, or via a detachable input device, as are well known in the art for interfacing programmable logic controllers.

[0051] Program storage memory 380 and data storage memory 390 can each comprise volatile (RAM) and non-volatile (ROM) memory units and can also comprise hard disk and backup storage capacity, and both program storage memory 380 and data storage memory 390 can be embodied in a single memory device or separated in plural memory devices. Program storage memory 380 stores software program modules and associated data, and in particular stores one or more indicative property calculation modules 381-385 such as cetane number calculation module 381, a pour point calculation module 382, a cloud point calculation module 383, an aniline point calculation module 384, and an octane number calculation module 385. Data storage memory 390 stores data used and/or generated by the one or more modules of the present system, including density of the crude oil sample in certain embodiments, NMR spectroscopy data or portions thereof used by the one or more modules of the present system, and calculated indicative properties generated by the one or more modules of the present system.

[0052] The calculated and assigned results in accordance with the systems and methods herein are displayed, audibly outputted, printed, and/or stored to memory for use as described herein.

[0053] It is to be appreciated that the computer system 300 can be any general or special purpose computer such as a personal computer, minicomputer, workstation, mainframe, a dedicated controller such as a programmable logic controller, or a combination thereof. While the computer system 300 is shown, for illustration purposes, as a single computer unit, the system can comprise a group/farm of computers which can be scaled depending on the processing load and database size, e.g., the total number of samples that are processed and results maintained on the system. The computer system 300 can serve as a common multi-tasking computer.

[0054] The computing device 300 preferably supports an operating system, for example, stored in program storage memory 390 and executed by the processor 310 from volatile memory. According to the present system and method, the operating system contains instructions for interfacing the device 300 to the calculation module(s). According to an embodiment of the invention, the operating system contains instructions for interfacing computer system 300 to the Internet and/or to private networks.

Example

[0055] Crude oil solutions were analyzed by .sup.13C and .sup.1H NMR spectrometry. The quantitative NMR spectra were recorded at room temperature on a Varian VNMS 500 NMR spectrometer operating at 499.78 MHz for .sup.1H and 125.67 MHz for .sup.13C, respectively, using Dual Broadband SW/PFG probe with 5 mm 506-PP (Wilmad Glass CO., Inc.) NMR sample tubes. The NMR experiments were carried out using 40% w/v sample solution in deuterated chloroform (99.8% D, Cambridge Isotope Laboratories Inc.) with tetramethylsilane (TMS) used as an internal standard. .sup.1H was performed using 16 scan numbers, 45 degree pulse length of 4.75 us, 5 s relaxation delay, 3 s acquisition time, 10 K time domain data, 15060 Hz spectra width and, 64 repetitions.

[0056] A quantitative .sup.13C analysis was performed and an inverse gated WALTZ-16 modulated decoupling mode was used to suppress nuclear Overhauser enhancement. The experimental parameter were: 30 degree pulse length of 2.7 us with a relaxation delay of 10 s, 1.69 s acquisition time, 128 K time domain data, 35878 Hz spectra width and typical 6000 repetitions were employed. Data was processed with 5 Hz line broadening.

[0057] .sup.13C NMR spectra were obtained for all the oils and an example of the spectra is shown in FIG. 1. As seen in this figure, the paraffinic, olefinic and aromatic carbons are identified on different regions of the spectra; the amounts of these carbons were determined by integrating the peaks identified. The carbon types were determined in the spectrum as having an aromatic region (165-100 ppm) and an aliphatic region (75-5 ppm).

[0058] As for the paraffinic and naphthenic, the 75-5 ppm region of the spectrum is used to define integrals wherever a paraffin resonance is found. In this area total paraffinic carbons are determined. It is assumed that all narrow resonances are paraffinic, and that any obvious broader NMR peak groups that represent a superposition of narrow paraffinic resonances are 100% paraffinic. The naphthenic humps were removed from the spectrum first to determine the paraffinic carbons. The difference between the total paraffinic carbon and the paraffinic carbon determined the total naphthenic carbon.

[0059] As for .sup.1H NMR, the paraffinic and aromatic hydrogens were determined in the spectrum in the following regions:

TABLE-US-00003 Hydrogen Type Shift in Spectrum Methyl (CH.sub.3) protons of alkyl chains (γ) or further  0.5-1.0 ppm from the aromatic ring or methyl protons (CH.sub.3) of saturated compounds (HS.sub.CH3). Methylene (CH.sub.2) and methane (CH) protons of alkyl 1.00-2.00 ppm chains (β) or further to ring and methyl (CH.sub.3) protons (β) to the ring (HSβ + γ). Aromatic proton 6.00-10.00 ppm 

HS-Hydrogen Saturated

[0060] Exemplary constants for equations (2) through (6) for use with the first embodiment equation (1), X1.sub.CET-X6.sub.CET, X1.sub.PP-X6.sub.PP, X1.sub.CP-X6.sub.CP, X1.sub.AP-X6.sub.AP, and X1.sub.RON-X6.sub.RON, were developed using linear regression techniques, and are given in Table 3.

TABLE-US-00004 TABLE 3 CET PP CP AP RON X1 −843.8 −1340.0 −797.2 −483.6 1196.0 X2 744.0 420.7 32.2 368.5 −940.8 X3 381.6 2053.9 1792.0 723.7 373.5 X4 1149.6 1729.9 1045.6 699.9 −1561.5 X5 −808.7 −532.4 −84.6 −378.6 1075.1 X6 −954.5 −6502.8 −5639.8 −2207.0 −964.7

[0061] Exemplary constants for equations (8) through (12) for use with the second embodiment equation (7), X1.sub.CET-X7.sub.CET, X1.sub.PP-X7.sub.PP, X1.sub.CP-X7.sub.CP, X1.sub.AP-X7.sub.AP, and X1.sub.RON-X7.sub.RON, were developed using linear regression techniques, and are given in Table 4.

TABLE-US-00005 TABLE 4 CET PP CP AP RON) X1 −112.8 −213.5 −125.9 −91.0 −277.5 X2 −672.8 −1016.4 −606.3 −345.6 1562.4 X3 995.0 895.7 312.4 571.0 −321.2 X4 −282.1 798.0 1051.1 188.1 −1130.1 X5 1078.4 1595.2 966.1 642.5 −1664.9 X6 −945.2 −790.8 −236.9 −488.8 734.0 X7 1509.4 −1840.3 −2889.4 −218.6 4692.3

[0062] Exemplary constants for equations (2) through (6) for use with the third embodiment equation (13), X1.sub.CET-X6.sub.CET, X1.sub.PP-X6.sub.PP, X1.sub.CP-X6.sub.CP, X1.sub.AP-X6.sub.AP, and X1.sub.RON-X6.sub.RON, were developed using linear regression techniques, and are given in Table 5.

TABLE-US-00006 TABLE 5 CET PP CP AP RON X1 −626.8 −4361.5 −2140.8 −620.3 2504.3 X2 −2545.8 −2815.3 −3317.9 −38.7 −8517.3 X3 37798.5 56783.6 50969.3 6716.1 84573.1 X4 692.8 7448.9 3728.6 931.3 −3537.2 X5 2372.4 2888.7 3172.0 139.7 7837.1 X6 −415665.2 −625842.1 −561527.6 −79178.8 −921508.7

[0063] Exemplary constants for equations (8) through (12) for use with the fourth embodiment equation (14), X1.sub.CET-X7.sub.CET, X1.sub.PP-X7.sub.PP, X1.sub.CP-X7.sub.CP, X1.sub.AP-X7.sub.AP, and X1.sub.RON-X7.sub.RON, were developed using linear regression techniques, and are given in Table 6.

TABLE-US-00007 TABLE 6 CET PP CP AP RON X1 −399.0 −332.0 −174.4 −436.0 −233.8 X2 −3093.2 −6414.2 −3218.8 −3315.4 −465.4 X3 4465.7 3020.0 −253.5 7622.9 −5649.6 X4 −10114.5 16908.0 30028.9 −45639.7 81342.3 X5 4191.5 10360.7 5257.7 4754.4 1038.7 X6 −4177.3 −2562.3 309.4 −7017.3 5163.5 X7 107503.5 −190434.4 −332876.3 492501.2 −890961.9

[0064] The following example is provided. A sample of Arabian medium crude with a 15° C./4° C. density of 0.8828 Kg/l (e.g., at 15° C./4° C. using the method described in ASTM D4052) was analyzed by .sup.13C NMR spectroscopy. The crude oil fractional weight composition is 0.279 naphthenic, 0.529 paraffinic, and 0.192 aromatic carbon.

[0065] Applying equation (8) and the constants from Table 4,

Cetane Number (CET)=X1.sub.CET*DEN+X2.sub.CET*C.sub.N+X3.sub.CET*C.sub.P+X4.sub.CET*C.sub.A+X5.sub.CET*C.sub.N.sup.2+X6.sub.CET*C.sub.P.sup.2+X7.sub.CET*C.sub.A.sup.2

=(−112.8)(0.8828)+(−672.8)(0.279)+(995.0)(0.529)+(−282.1)(0.192)+(1078.4)(0.279).sup.2+(−945.2)(0.529).sup.2+(1509.4)(0.192).sup.2

CET=60

[0066] Applying equation (9) and the constants from Table 4,

Pour Point (PP)=X1.sub.PP*DEN+X2.sub.PP*C.sub.N+X3.sub.PP*C.sub.P+X4.sub.PP*C.sub.A+X5.sub.PP*C.sub.N.sup.2+X6.sub.PP*C.sub.P.sup.2+X7.sub.PP*C.sub.A.sup.2

=(−213.5)(0.8828)+(−1016.4)(0.279)+(895.7)(0.529)+(798.0)(0.192)+(1595.2)(0.279).sup.2+(−790.8)(0.529).sup.2+(−1840.3)(0.192).sup.2

PP=−10° C.

[0067] Applying equation (10) and the constants from Table 4,

Cloud Point (CP)=X1.sub.CP*DEN+X2.sub.CP*C.sub.N+X3.sub.CP*C.sub.P+X4.sub.CP*C.sub.A+X5.sub.CP*C.sub.N.sup.2+X6.sub.CP*C.sub.P.sup.2+X7.sub.CP*C.sub.A.sup.2

=(−125.9)(0.8828)+(−606.3)(0.279)+(312.4)(0.529)+(1051.1)(0.192)+(966.1)(0.279).sup.2+(−236.9)(0.529).sup.2+(−2889.4)(0.192).sup.2

CP=−11° C.

[0068] Applying equation (11) and the constants from Table 4,

Aniline Point (AP)=X1.sub.AP*DEN+X2.sub.AP*C.sub.N+X3.sub.AP*C.sub.P+X4.sub.AP*C.sub.A+X5.sub.AP*C.sub.N.sup.2+X6.sub.AP*C.sub.P.sup.2+X7.sub.AP*C.sub.A.sup.2

=(−91.0)(0.8828)+(−345.6)(0.279)+(571.0)(0.529)+(188.1)(0.192)+(642.5)(0.279).sup.2+(−488.8)(0.529).sup.2+(−218.6)(0.192).sup.2

AP=67° C.

[0069] Applying equation (12) and the constants from Table 4,

Octane Number (RON)=X1.sub.RON*DEN+X2.sub.RON*C.sub.N+X3.sub.RON*C.sub.P+X4.sub.RON*C.sub.A+X5.sub.RON*C.sub.N.sup.2+X6.sub.RON*C.sub.P.sup.2+X7.sub.RON*C.sub.A.sup.2

=(−277.5)(0.8828)+(1562.4)(0.279)+(−321.2)(0.529)+(−1130.1)(0.192)+(−1664.9)(0.279).sup.2+(734.0)(0.529).sup.2+(4692.3)(0.192).sup.2

RON=53

[0070] Accordingly, as shown in the above example, indicative properties including cetane number, pour point, cloud point and aniline point can be assigned to the crude oil samples without fractionation/distillation (crude oil assays).

[0071] In alternate embodiments, the present invention can be implemented as a computer program product for use with a computerized computing system. Those skilled in the art will readily appreciate that programs defining the functions of the present invention can be written in any appropriate programming language and delivered to a computer in any form, including but not limited to: (a) information permanently stored on non-writeable storage media (e.g., read-only memory devices such as ROMs or CD-ROM disks); (b) information alterably stored on writeable storage media (e.g., floppy disks and hard drives); and/or (c) information conveyed to a computer through communication media, such as a local area network, a telephone network, or a public network such as the Internet. When carrying computer readable instructions that implement the present invention methods, such computer readable media represent alternate embodiments of the present invention.

[0072] As generally illustrated herein, the system embodiments can incorporate a variety of computer readable media that comprise a computer usable medium having computer readable code means embodied therein. One skilled in the art will recognize that the software associated with the various processes described can be embodied in a wide variety of computer accessible media from which the software is loaded and activated. Pursuant to In re Beauregard, 35 USPQ2d 1383 (U.S. Pat. No. 5,710,578), the present invention contemplates and includes this type of computer readable media within the scope of the invention. In certain embodiments, pursuant to In re Nuuten, 500 F.3d 1346 (Fed. Cir. 2007) (U.S. patent application Ser. No. 09/211,928), the scope of the present claims is limited to computer readable media, wherein the media is both tangible and non-transitory.

[0073] The system and method of the present invention have been described above and with reference to the attached figures; however, modifications will be apparent to those of ordinary skill in the art and the scope of protection for the invention is to be defined by the claims that follow.