U.S. patent application number 14/987810 was filed with the patent office on 2016-07-07 for characterization of crude oil and its fractions by fluorescence spectroscopy analysis.
The applicant listed for this patent is Saudi Arabian Oil Company. Invention is credited to Adnan Al-Hajji, Omer Refa Koseoglu.
Application Number | 20160195508 14/987810 |
Document ID | / |
Family ID | 55229857 |
Filed Date | 2016-07-07 |
United States Patent
Application |
20160195508 |
Kind Code |
A1 |
Al-Hajji; Adnan ; et
al. |
July 7, 2016 |
CHARACTERIZATION OF CRUDE OIL AND ITS FRACTIONS BY FLUORESCENCE
SPECTROSCOPY ANALYSIS
Abstract
A system and a method are provided for calculating the cetane
number, pour point, cloud point, aniline point, aromaticity, and/or
octane number of a crude oil and its fractions from the density and
fluorescence spectroscopy of a sample of the crude oil.
Inventors: |
Al-Hajji; Adnan; (Dhahran,
SA) ; Koseoglu; Omer Refa; (Dhahran, SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Saudi Arabian Oil Company |
Dhahran |
|
SA |
|
|
Family ID: |
55229857 |
Appl. No.: |
14/987810 |
Filed: |
January 5, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62099703 |
Jan 5, 2015 |
|
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Current U.S.
Class: |
250/301 ;
250/206 |
Current CPC
Class: |
G01N 33/2811 20130101;
G01N 2201/12 20130101; G01N 33/2823 20130101; G01N 21/645 20130101;
G01N 21/64 20130101; G01N 33/30 20130101 |
International
Class: |
G01N 33/28 20060101
G01N033/28; G01N 21/64 20060101 G01N021/64; G01N 33/30 20060101
G01N033/30 |
Claims
1. A system for evaluating a crude oil sample and calculating an
indicative property of a naphtha or gas oil fraction of the crude
oil sample without first distilling said naphtha or gas oil
fraction, the system comprising: a fluorometer that outputs
fluorescence spectroscopy data; a non-volatile memory device that
stores calculation modules and data, the data including density of
the crude oil sample and fluorescence spectroscopy data indicative
of absorbance units at predetermined increments between a
predetermined range for the oil sample, as derived by an analysis
of the crude oil sample by the fluorometer; a processor coupled to
the non-volatile memory; a first calculation module that retrieves
the fluorescence spectroscopy data from the non-volatile memory
device, calculates a crude oil fluorescence spectroscopy index
value of the fraction from the absorbance units of the fluorescence
spectroscopy data, and transfers the calculated crude oil
fluorescence spectroscopy index value into the non-volatile memory;
and a second calculation module that calculates the indicative
property for the naphtha or gas oil fraction of the crude oil from
a two-variable polynomial equation with predetermined constant
coefficients developed using linear regression techniques, and that
stores the indicative property into the non-volatile memory device;
wherein the two variables of the two-variable polynomial equation
are the crude oil fluorescence spectroscopy index and the density
of the crude oil sample.
2. The system of claim 1, wherein the indicative property is the
cetane number.
3. The system of claim 1, wherein the indicative property is the
pour point.
4. The system of claim 1, wherein the indicative property is the
cloud point.
5. The system of claim 1, wherein the indicative property is the
aniline point.
6. The system of claim 1, wherein the indicative property is the
aromaticity.
7. The system of claim 1, wherein the indicative property is the
octane number.
8. The system of claim 1, wherein the temperature range for the
fluorometer is 20-1000.degree. C.
9. The system of claim 1, wherein the fluorescence spectroscopy
index is that of whole crude oil.
10. The system of claim 1, wherein the fluorescence spectroscopy
index is calculated from fluorescence spectroscopy data measured in
the wavelength range of 250-800 nm.
11. The system of claim 1, wherein the fluorescence spectroscopy
data is obtained directly from core and/or drill cuttings
material.
12. A method for evaluating a crude oil sample and calculating an
indicative property of a naphtha or gas oil fraction of the crude
oil sample without first distilling said naphtha or gas oil
fraction, the method comprising: obtaining density of the crude oil
sample; providing a fluorometer that outputs fluorescence
spectroscopy data subjecting said crude oil sample to fluorescence
spectroscopy analysis using the fluorometer, and entering
absorbance units of the fluorescence spectroscopy data into
non-volatile memory of a computer; using a processor of the
computer to calculate a crude oil fluorescence spectroscopy index
value of the fraction from the absorbance units of the spectroscopy
data; and using the processor to calculate and enter into the
non-volatile memory the indicative property for the naphtha or gas
oil fraction of the crude oil from a two-variable polynomial
equation with predetermined constant coefficients developed using
linear regression techniques; wherein the two variables of the
two-variable polynomial equation are the crude oil fluorescence
spectroscopy index and the density of the crude oil sample.
13. The method of claim 12, wherein the indicative property is the
cetane number.
14. The method of claim 12, wherein the indicative property is the
pour point.
15. The method of claim 12, wherein the indicative property is the
cloud point.
16. The method of claim 12, wherein the indicative property is the
aniline point.
17. The method of claim 12, wherein the indicative property is the
aromaticity.
18. The method of claim 12, wherein the indicative property is the
octane number.
19. The method of claim 12, wherein the temperature range for the
fluorometer is 20-1000.degree. C.
20. The method of claim 12, wherein the fluorescence spectroscopy
index is that of whole crude oil.
21. The method of claim 12, wherein the fluorescence spectroscopy
index is calculated from fluorescence spectroscopy data measured in
the wavelength range of 250-800 nm.
22. The method of claim 12, wherein the fluorescence spectroscopy
data is obtained directly from core and/or drill cuttings material.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 62/099,703 filed Jan. 5, 2015, the
disclosure of which is incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a method and process for the
evaluation of samples of crude oil and its fractions by
fluorescence spectroscopy analysis.
BACKGROUND OF THE INVENTION
[0003] Crude oil originates from the decomposition and
transformation of aquatic, mainly marine, living organisms and/or
land plants that became buried under successive layers of mud and
silt some 15-500 million years ago. They are essentially very
complex mixtures of many thousands of different hydrocarbons.
Depending on the source, the oil predominantly contains various
proportions of straight and branched-chain paraffins,
cycloparaffins, and naphthenic, aromatic, and polynuclear aromatic
hydrocarbons. These hydrocarbons can be gaseous, liquid, or solid
under normal conditions of temperature and pressure, depending on
the number and arrangement of carbon atoms in the molecules.
[0004] Crude oils vary widely in their physical and chemical
properties from one geographical region to another and from field
to field. Crude oils are usually classified into three groups
according to the nature of the hydrocarbons they contain:
paraffinic, naphthenic, asphaltic, and their mixtures. The
differences are due to the different proportions of the various
molecular types and sizes. One crude oil can contain mostly
paraffins, another mostly naphthenes. Whether paraffinic or
naphthenic, one can contain a large quantity of lighter
hydrocarbons and be mobile or contain dissolved gases; another can
consist mainly of heavier hydrocarbons and be highly viscous, with
little or no dissolved gas. Crude oils can also include heteroatoms
containing sulfur, nitrogen, nickel, vanadium and other elements in
quantities that impact the refinery processing of the crude oil
fractions. Light crude oils or condensates can contain sulfur in
concentrations as low as 0.01 W %; in contrast, heavy crude oils
can contain as much as 5-6 W %. Similarly, the nitrogen content of
crude oils can range from 0.001-1.0 W %. The nature of the crude
oil governs, to a certain extent, the nature of the products that
can be manufactured from it and their suitability for special
applications. A naphthenic crude oil will be more suitable for the
production of asphaltic bitumen, a paraffinic crude oil for wax. A
naphthenic crude oil, and even more so an aromatic one, will yield
lubricating oils with viscosities that are sensitive to
temperature. However, with modern refining methods there is greater
flexibility in the use of various crude oils to produce many
desired type of products.
[0005] A crude oil assay is a traditional method of determining the
nature of crude oils for benchmarking purposes. Crude oils are
subjected to true boiling point (TBP) distillations and
fractionations to provide different boiling point fractions. The
crude oil distillations are carried out using the American Standard
Testing Association (ASTM) Method D 2892. The common fractions and
their nominal boiling points are given in Table 1.
TABLE-US-00001 TABLE 1 Fraction Boiling Point, .degree. C. Methane
-161.5 Ethane -88.6 Propane -42.1 Butanes -6.0 Light Naphtha 36-90
Mid Naphtha 90-160 Heavy Naphtha 160-205 Light gas Oil 205-260 Mid
Gas Oil 260-315 Heavy gas Oil 315-370 Light Vacuum Gas Oil 370-430
Mid Vacuum Gas Oil 430-480 Heavy vacuum gas oil 480-565 Vacuum
Residue 565+
[0006] The yields, composition, physical and indicative properties
of these crude oil fractions, where applicable, are then determined
during the crude assay work-up calculations. Typical compositional
and property information obtained from a crude oil assay is given
in Table 2.
TABLE-US-00002 TABLE 2 Property Unit Property Type Fraction Yield
Weight and Volume % W % Yield All API Gravity .degree. Physical All
Viscosity Kinematic @ 38.degree. C. .degree. Physical Fraction
boiling >250.degree. C. Refractive Index @ 20.degree. C.
Unitless Physical Fraction boiling <400.degree. C. Sulfur W %
Composition All Mercaptan Sulfur, W % W % Composition Fraction
boiling <250.degree. C. Nickel ppmw Composition Fraction boiling
>400.degree. C. Nitrogen ppmw Composition All Flash Point, COC
.degree. C. Indicative All Cloud Point .degree. C. Indicative
Fraction boiling >250.degree. C. Pour Point, (Upper) .degree. C.
Indicative Fraction boiling >250.degree. C. Freezing Point
.degree. C. Indicative Fraction boiling >250.degree. C. Micro
Carbon Residue W % Indicative Fraction boiling >300.degree. C.
Smoke Point, mm mm Indicative Fraction boiling between
150-250.degree. C. Octane Number Unitless Indicative Fraction
boiling <250.degree. C. Cetane Index Unitless Indicative
Fraction boiling between 150-400.degree. C. Aniline Point .degree.
C. Indicative Fraction boiling <520.degree. C.
[0007] Due to the number of distillation cuts and the number of
analyses involved, the crude oil assay work-up is both costly and
time consuming.
[0008] In a typical refinery, crude oil is first fractionated in
the atmospheric distillation column to separate sour gas and light
hydrocarbons, including methane, ethane, propane, butanes and
hydrogen sulfide, naphtha (36-180.degree. C.), kerosene
(180-240.degree. C.), gas oil (240-370.degree. C.) and atmospheric
residue (>370.degree. C.). The atmospheric residue from the
atmospheric distillation column is either used as fuel oil or sent
to a vacuum distillation unit, depending on the configuration of
the refinery. The principal products obtained from vacuum
distillation are vacuum gas oil, comprising hydrocarbons boiling in
the range 370-520.degree. C., and vacuum residue, comprising
hydrocarbons boiling above 520.degree. C. Crude assay data is
conventionally obtained from individual analysis of these cuts to
help refiners to understand the general composition of the crude
oil fractions and properties so that the fractions can be processed
most efficiently and effectively in an appropriate refining unit.
Indicative properties are used to determine the engine/fuel
performance or usability or flow characteristic or composition. A
summary of the indicative properties and their determination
methods with description is given below.
[0009] The cetane number of diesel fuel oil, determined by the ASTM
D613 method, provides a measure of the ignition quality of diesel
fuel; as determined in a standard single cylinder test engine;
which measures ignition delay compared to primary reference fuels.
The higher the cetane number; the easier the high-speed;
direct-injection engine will start; and the less white smoking and
diesel knock after start-up are. The cetane number of a diesel fuel
oil is determined by comparing its combustion characteristics in a
test engine with those for blends of reference fuels of known
cetane number under standard operating conditions. This is
accomplished using the bracketing hand wheel procedure which varies
the compression ratio (hand wheel reading) for the sample and each
of the two bracketing reference fuels to obtain a specific ignition
delay, thus permitting interpolation of cetane number in terms of
hand wheel reading.
[0010] The cloud point, determined by the ASTM D2500 method, is the
temperature at which a cloud of wax crystals appears when a
lubricant or distillate fuel is cooled under standard conditions.
Cloud point indicates the tendency of the material to plug filters
or small orifices under cold weather conditions. The specimen is
cooled at a specified rate and examined periodically. The
temperature at which cloud is first observed at the bottom of the
test jar is recorded as the cloud point. This test method covers
only petroleum products and biodiesel fuels that are transparent in
40 mm thick layers, and with a cloud point below 49.degree. C.
[0011] The pour point of petroleum products, determined by the ASTM
D97 method, is an indicator of the ability of oil or distillate
fuel to flow at cold operating temperatures. It is the lowest
temperature at which the fluid will flow when cooled under
prescribed conditions. After preliminary heating, the sample is
cooled at a specified rate and examined at intervals of 3.degree.
C. for flow characteristics. The lowest temperature at which
movement of the specimen is observed is recorded as the pour
point.
[0012] The aniline point, determined by the ASTM D611 method, is
the lowest temperature at which equal volumes of aniline and
hydrocarbon fuel or lubricant base stock are completely miscible. A
measure of the aromatic content of a hydrocarbon blend is used to
predict the solvency of a base stock or the cetane number of a
distillate fuel. Specified volumes of aniline and sample, or
aniline and sample plus n-heptane, are placed in a tube and mixed
mechanically. The mixture is heated at a controlled rate until the
two phases become miscible. The mixture is then cooled at a
controlled rate and the temperature at which two separate phases
are again formed is recorded as the aniline point or mixed aniline
point.
[0013] The octane number, determined by the ASTM D2699 or D2700
methods, is a measure of a fuel's ability to prevent detonation in
a spark ignition engine. Measured in a standard single-cylinder;
variable-compression-ratio engine by comparison with primary
reference fuels. Under mild conditions, the engine measures
research octane number (RON), while under severe conditions, the
engine measures motor octane number (MON). Where the law requires
posting of octane numbers on dispensing pumps, the antiknock index
(AKI) is used. This is the arithmetic average of RON and MON,
(R+M)/2. It approximates the road octane number, which is a measure
of how an average car responds to the fuel.
[0014] To determine these properties of gas oil or naphtha
fractions conventionally, these fractions have to be distilled from
the crude oil and then measured/identified using various analytical
methods that are laborious, costly and time-consuming.
[0015] Fluorescence spectrometry is a sensitive and selective
analytical method for aromatic-containing samples like crude oil.
Therefore, it is particularly useful for the determination of
condensed aromatic or heteroaromatic ring compounds in crude oil.
Fluorescence occurs when a fluorescent material is excited by
absorbing an incident light (photon) into a higher electronic state
which will return to the ground state after emitting light (a
photon) from the ground vibrational level of the excited electronic
state. The emitted photon goes to an excited vibrational state of
the ground electronic state. The structure and environments of the
fluorescent material can be deduced from the energies and relative
intensities of the fluorescence signals.
[0016] A fluorescence emission spectrum is recorded when the
excitation wavelength of light is held constant and the emission
beam is scanned as a function of wavelength. An excitation spectrum
is the opposite, whereby the emission light is held at a constant
wavelength, and the excitation light is scanned as a function of
wavelength. The excitation spectrum usually resembles the
absorbance spectrum in shape.
[0017] Synchronous fluorescence spectrometry is the method of
choice to improve the selectivity of the measurement by taking full
advantage of the ability to vary both the excitation and the
emission wavelength during analysis. Excitation and emission
wavelengths are scanned simultaneously while maintaining a constant
wavelength difference between the two modes. This method has been
proved successful for materials like polycyclic aromatic
hydrocarbons.
[0018] This invention discloses a system and method in which
fluorescence spectroscopy analysis is employed to disclose physical
and indicative properties (i.e., cetane number, pour point, cloud
point, and aniline point) of gas oil fraction of crude oils, as
well as the octane number of the naphtha fraction and the
aromaticity of whole crude oils. The invention provides insight
into the gas oil 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 going thru costly and time consuming crude oil assays.
Whereas a conventional crude oil assay method could take up to two
months, this invention provides results within one hour.
[0019] New rapid, and direct methods to help better understand
crude oil compositions and properties from analysis of whole crude
oil will save producers, marketers, refiners and/or other crude oil
users substantial expense, effort and time. Therefore, a need
exists for an improved system and method for determining indicative
properties of crude oil fractions from different sources.
SUMMARY OF THE INVENTION
[0020] Systems and methods for determining one or more indicative
properties of a hydrocarbon sample are presented. Indicative
properties in a crude oil sample (e.g., cetane number, pour point,
cloud point and aniline point) of a gas oil fraction, octane number
of a naphtha fraction, and the aromaticity for the whole crude oil
(WCO), are assigned as a function of density and fluorescence
spectroscopy measurement of a crude oil sample. The indicative
properties provide information about the gas oil and naphtha
properties without fractionation/distillation (crude oil assays)
and 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] 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:
[0022] FIG. 1 is a graphic plot of typical fluorescence
spectroscopy data for typical crude oil samples with different API
gravities;
[0023] FIG. 2 is a block diagram of a method in which an embodiment
of the invention is implemented;
[0024] FIG. 3 is a schematic block diagram of modules of an
embodiment of the invention; and
[0025] FIG. 4 is a block diagram of a computer system in which an
embodiment of the invention is implemented.
DETAILED DESCRIPTION OF INVENTION
[0026] A system and a method are 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 and ozone number of a naphtha
fraction in a crude oil sample are assigned as a function of the
density and fluorescence spectroscopy measurement of the crude oil
sample. The indicative properties provide information about the gas
oil and naphtha properties without fractionation/distillation
(crude oil assays) and 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.
[0027] 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.
[0028] In the system and method herein, fluorescence spectroscopy
analysis is obtained by a suitable known or to-be-developed
process. Fluorescence spectroscopy uses a fluorometer to collect
spectral data of a solid, liquid, or gas.
[0029] In one embodiment, a Varian Cary Eclipse fluorescence
spectrophotometer (i.e., fluorometer) was used for the analysis of
the crude oil. The synchronization scanning mode was utilized, with
a delta of 15 nm, and a scan range from 250-800 nm.
[0030] Typical fluorescence spectroscopy data for crude oils with
different API gravities is shown in FIG. 1.
[0031] In one embodiment, the fluorescence spectroscopy index is
calculated as follows. The absorbance unit at each wavelength
(integer) of the scan range is summed, and then the total is
divided by 1000.
FSMI crude_oil = f = 250 800 ( Absorbance Unit ) / ( 1000 ) ( 1 )
##EQU00001##
[0032] FIG. 2 shows a process flowchart of steps in a method
according to one embodiment herein, in which crude oil samples are
prepared and analyzed by fluorescence spectroscopy according to the
method 200 described below.
[0033] In step 210 a sample of crude oil is dissolved in hexane and
then scanned by the fluorometer over the wavelength range from
250-800 nm.
[0034] In step 215, the fluorescence spectroscopy data is arranged
by wavelength and absorbance unit.
[0035] In step 220, a fluorescence spectroscopy index is calculated
according to equation (1).
[0036] The indicative properties (e.g., the cetane number, pour
point, cloud point and aniline point) of the gas oil fraction, e.g.
boiling in the range of 150-400.degree. C. and in certain
embodiments in the range of 180-370.degree. C., the octane number
of the naphtha fraction, and the aromaticity for the whole crude
oil (WCO), can be assigned as a function of the density and the
fluorescence spectroscopy index of crude oil. That is,
Indicative Property=f(density.sub.crude oil,FSMI.sub.crudeoil)
(2);
[0037] Equation (3) is a detailed example of this relationship,
showing the cetane number, pour point, cloud point and aniline
point that can be predicted for the gas oil (GO) fraction of the
crude oil, as well as the aromaticity that can be predicted for the
whole crude oil (WCO), as well as the octane number that can be
predicted for the naphtha fraction.
[0038] In steps 235, 240, 245, and 250, respectively, the
properties of a cetane number, pour point, cloud point and aniline
point for the gas oil (GO) fraction of the crude oil are
calculated, in step 253 the aromaticity for the whole crude oil
(WCO) is calculated, and in step 255 the property of an octane
number for the naphtha fraction of the crude oil is calculated.
While FIG. 2 shows the steps performed sequentially, they can be
performed in parallel or in any order. In certain embodiments, only
one or more steps 235, 240, 245, 250, 253, 255 are carried out. In
these steps, the one or more indicative properties are determined
as follows:
Indicative
property=K+X1*DEN+X2*DEN.sup.2+X3*DEN.sup.3+X4*FSMI+X5*FSMI.sup.2+X6*FSMI-
.sup.3+X7*DEN*FSMI (3);
[0039] where:
[0040] DEN=density of the crude oil sample; and
[0041] K, X1-X7, are constants for the properties to be predicted
that are developed using linear regression analysis of hydrocarbon
data from fluorescence spectrometry data.
[0042] FIG. 3 illustrates a schematic block diagram of modules in
accordance with an embodiment of the present invention, system 300.
Density and raw data receiving module 310 receives the density of a
sample of crude oil and fluorescence spectroscopy data derived from
the crude oil.
[0043] Fluorescence spectroscopy index calculation module 315
calculates the fluorescence spectroscopy index from the spectral
data.
[0044] Cetane number calculation module 335 derives the cetane
number for the gas oil fraction of the crude oil as a function of
the fluorescence spectroscopy index and density of the sample.
[0045] Pour point calculation module 340 derives the pour point for
the gas oil fraction of the crude oil as a function of the
fluorescence spectroscopy index and density of the sample.
[0046] Cloud point calculation module 345 derives the cloud point
for the gas oil fraction of the crude oil as a function of the
fluorescence spectroscopy index and density of the sample.
[0047] Aniline point calculation module 350 derives the aniline
point for the gas oil fraction of the crude oil as a function of
the fluorescence spectroscopy index and density of the sample.
[0048] Aromaticity calculation module 352 derives the aromaticity
for the whole crude oil as a function of the fluorescence
spectroscopy index and density of the sample.
[0049] Octane number calculation module 355 derives the octane
number for the naphtha fraction of the crude oil as a function of
the fluorescence spectroscopy index and density of the sample.
[0050] FIG. 4 shows an exemplary block diagram of a computer system
400 in which one embodiment of the present invention can be
implemented. Computer system 400 includes a processor 420, such as
a central processing unit, an input/output interface 430 and
support circuitry 440. In certain embodiments, where the computer
system 400 requires a direct human interface, a display 410 and an
input device 450 such as a keyboard, mouse or pointer are also
provided. The display 410, input device 450, processor 420, and
support circuitry 440 are shown connected to a bus 490 which also
connects to a memory 460. Memory 460 includes program storage
memory 470 and data storage memory 480. Note that while computer
system 400 is depicted with direct human interface components
display 410 and input device 450, programming of modules and
exportation of data can alternatively be accomplished over the
input/output interface 430, for instance, where the computer system
400 is connected to a network and the programming and display
operations occur on another associated computer, or via a
detachable input device as is known with respect to interfacing
programmable logic controllers.
[0051] Program storage memory 470 and data storage memory 480 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 470 and data storage memory 480 can be
embodied in a single memory device or separated in plural memory
devices. Program storage memory 470 stores software program modules
and associated data, and in particular stores a density and raw
data receiving module 310, fluorescence spectroscopy index
calculation module 315, cetane number calculation module 335, pour
point calculation module 340, cloud point calculation module 345,
aniline point calculation module 350, aromaticity calculation
module 352, and octane number calculation module 355. Data storage
memory 480 stores results and other data generated by the one or
more modules of the present invention.
[0052] It is to be appreciated that the computer system 400 can be
any 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 400 is shown, for illustration purposes, as a
single computer unit, the system can comprise a group of computers
which can be scaled depending on the processing load and database
size.
[0053] Computer system 400 preferably supports an operating system,
for example stored in program storage memory 470 and executed by
the processor 420 from volatile memory. According to an embodiment
of the invention, the operating system contains instructions for
interfacing computer system 400 to the Internet and/or to private
networks.
Example 1
[0054] A set of constants K and X1-X7 was determined using linear
regression for the indicative properties cetane number, pour point,
cloud point, aniline point, octane number, and aromaticity. These
constants were determined based on known actual distillation data
for plural crude oil samples and their corresponding indicative
properties. These constants are given in Table 3.
TABLE-US-00003 TABLE 3 Constants Cetane Number Pour Point Cloud
Point K -2.920657E+04 -2.283807E+04 8.016178E+04 X1 8.247657E+04
6.995129E+04 -2.781445E+05 X2 -8.008823E+04 -7.232753E+04
3.199487E+05 X3 2.758504E+04 2.532512E+04 -1.219746E+05 X4
1.273387E+02 4.791017E+01 3.108188E+01 X5 4.207752E-01
-8.303909E-02 1.963374E-01 X6 -4.676128E-03 7.142002E-04
-1.983566E-03 X7 -1.581570E+02 -5.156225E+01 -4.212763E+01
Constants Aniline Point Octane Number WCO-AROM K -4.370054E+04
1.017323E+05 1.047903E+04 X1 1.449824E+05 -3.438191E+05
-4.741776E+04 X2 -1.608909E+05 3.877252E+05 6.274074E+04 X3
5.979962E+04 -1.457003E+05 -2.516125E+04 X4 2.649713E+01
-9.217455E+00 8.586987E+01 X5 -5.686953E-02 2.914821E-01
6.843602E-01 X6 3.346494E-04 -2.737219E-03 -7.078907E-03 X7
-2.749938E+01 0.000000E+00 -1.207479E+02
[0055] The following example is provided to demonstrate an
application of equations (3). A sample of Arabian medium crude with
a 15.degree. C./4.degree. C. density of 0.8828 Kg/1 was analyzed by
fluorescence spectroscopy, using the described method. The
tabulated results follow in Table 4:
TABLE-US-00004 TABLE 4 API Gravity, .degree. Wavelength (nm) 28.8
19.6 250 1.27 1.05 251 1.21 0.91 252 1.14 0.85 253 0.95 1.02 254
0.97 0.92 255 1.15 0.94 256 1.28 1.09 257 1.33 1.44 258 1.57 1.44
259 1.83 1.63 260 2.05 1.96 261 2.63 2.21 262 3.16 2.73 263 3.74
3.25 264 4.28 3.88 265 5.00 5.07 266 5.67 5.59 267 6.48 6.78 268
6.65 7.27 269 7.56 8.55 270 7.85 9.29 271 8.36 9.87 272 8.71 10.68
273 8.93 11.21 274 9.24 11.49 275 8.79 12.13 276 8.60 12.45 277
8.79 12.68 278 8.35 12.72 279 7.74 12.31 280 7.50 12.34 281 7.35
12.60 282 7.42 12.55 283 7.79 13.13 284 9.11 14.59 285 10.15 16.48
286 12.32 19.70 287 14.84 23.30 288 17.17 27.11 289 20.36 31.74 290
22.93 36.59 291 24.17 40.13 292 26.52 44.18 293 28.00 46.89 294
27.89 49.52 295 28.54 51.24 296 29.29 54.14 297 30.29 56.46 298
30.41 58.06 299 31.50 60.48 300 31.99 62.98 301 32.14 63.77 302
32.38 66.72 303 31.66 66.79 304 31.23 67.48 305 29.79 66.10 306
28.95 65.39 307 27.11 64.41 308 26.08 63.97 309 25.76 62.65 310
25.31 62.52 311 24.73 62.68 312 25.28 64.40 313 26.44 67.67 314
27.19 69.71 315 27.25 68.99 316 28.15 70.95 317 29.82 73.39 318
31.36 78.28 319 32.10 81.73 320 34.13 85.19 321 34.44 87.23 322
37.79 94.02 323 40.61 101.62 324 43.34 109.60 325 46.36 117.56 326
47.79 124.76 327 51.11 134.00 328 54.09 143.32 329 56.67 152.26 330
58.77 159.16 331 58.02 159.37 332 60.10 165.95 333 61.49 168.93 334
63.50 176.30 335 63.66 172.61 336 63.59 173.20 337 62.73 175.41 338
65.47 181.41 339 68.17 184.71 340 69.14 188.76 341 68.81 184.04 342
70.78 187.74 343 71.17 186.11 344 74.48 194.29 345 74.95 192.86 346
75.31 196.13 347 76.25 191.86 348 76.99 192.92 349 77.96 192.59 350
80.27 194.30 351 78.27 190.40 352 77.50 188.90 353 77.98 184.87 354
78.21 187.44 355 78.16 185.91 356 78.36 184.15 357 76.17 178.69 358
76.24 175.44 359 75.49 174.06 360 76.48 175.46 361 75.71 173.24 362
77.62 172.86 363 77.05 169.22 364 78.20 171.83 365 77.52 167.50 366
79.23 167.43 367 77.33 161.66 368 78.10 161.76 369 76.25 156.31 370
77.04 153.14 371 75.00 151.36 372 76.69 151.51 373 76.13 148.03 374
75.95 147.92 375 74.56 146.40 376 77.28 153.98 377 78.71 157.11 378
80.95 165.33 379 81.67 167.60 380 83.41 174.64 381 86.26 181.18 382
87.37 189.91 383 88.30 194.12 384 90.10 196.70 385 89.27 199.14 386
91.91 204.95 387 92.77 210.50 388 91.22 210.57 389 91.49 210.34 390
90.72 211.38 391 90.54 209.72 392 91.19 213.29 393 92.41 216.90 394
92.39 218.13 395 93.00 220.83 396 93.93 220.46 397 94.01 222.20 398
93.90 222.32 399 93.41 223.02 400 92.18 221.82 401 91.00 220.53 402
91.43 219.05 403 91.29 218.84 404 92.06 218.51 405 91.49 219.09 406
92.58 218.48 407 91.94 216.00 408 91.44 216.14 409 92.37 215.76 410
91.80 212.67 411 90.76 210.61 412 89.27 209.16 413 89.74 205.68 414
89.07 203.71 415 88.22 200.33 416 87.09 198.86 417 87.18 197.27 418
86.86 195.36 419 86.88 195.24 420 87.05 195.64 421 87.44 195.13 422
87.04 194.82 423 87.33 192.77 424 87.21 192.40 425 87.65 191.73 426
87.08 191.12 427 87.11 189.04 428 85.32 187.05 429 85.49 184.34 430
83.64 180.80 431 83.72 177.67 432 83.13 178.84 433 83.41 177.03 434
83.70 175.80 435 82.78 175.25 436 81.67 173.03 437 81.69 172.99 438
81.69 170.94 439 81.37 170.17 440 81.09 169.31 441 80.69 169.08 442
79.95 167.44 443 79.43 165.50 444 78.64 163.07 445 78.29 161.13 446
78.06 160.86 447 77.39 159.34 448 76.72 158.48 449 76.97 157.38 450
76.05 154.39 451 74.74 153.40 452 74.13 151.33 453 73.35 148.34 454
72.50 146.80 455 71.39 144.42 456 70.29 140.20 457 69.49 139.33 458
67.91 136.19 459 67.47 136.30 460 66.83 134.80 461 66.13 133.01 462
65.91 132.51 463 64.99 129.55 464 64.42 127.25 465 62.81 125.11 466
61.35 121.38 467 60.41 119.99 468 59.29 118.29 469 59.48 116.76 470
57.97 114.85 471 57.34 113.47 472 56.76 112.23 473 54.83 109.40 474
54.62 107.56 475 53.24 105.06 476 52.40 103.80 477 51.24 102.89 478
50.54 100.46 479 49.71 98.76 480 48.71 95.76 481 46.65 91.87 482
46.75 92.08 483 45.58 91.72 484 45.47 90.16 485 44.77 90.37 486
44.22 89.52 487 44.13 88.40 488 42.93 87.33 489 41.99 85.13 490
41.09 83.09 491 40.30 81.43 492 39.87 81.19 493 39.07 79.56 494
38.61 78.01
495 37.54 76.65 496 36.22 75.01 497 35.59 73.99 498 35.13 71.41 499
34.20 71.86 500 34.18 70.05 501 32.85 69.17 502 31.72 67.31 503
31.47 66.49 504 30.76 64.14 505 30.20 63.20 506 29.32 62.69 507
29.02 61.29 508 27.78 59.76 509 27.66 58.69 510 27.14 58.04 511
27.02 56.90 512 26.38 56.02 513 25.72 55.28 514 25.03 53.66 515
24.12 52.39 516 24.26 51.68 517 23.67 50.34 518 22.48 49.83 519
22.56 48.20 520 22.12 48.16 521 21.43 46.61 522 20.92 45.44 523
20.12 44.67 524 19.80 43.49 525 19.30 41.61 526 18.87 41.21 527
18.46 40.69 528 18.36 40.39 529 18.06 39.71 530 17.67 39.44 531
17.75 38.55 532 16.95 37.58 533 16.58 36.48 534 16.11 35.58 535
15.88 35.02 536 15.72 34.58 537 15.33 33.95 538 14.77 32.36 539
14.15 31.44 540 13.74 31.22 541 13.51 30.52 542 13.34 30.13 543
13.22 29.26 544 13.03 29.66 545 12.49 28.66 546 12.34 28.03 547
11.71 27.70 548 11.95 27.46 549 11.78 27.10 550 11.40 26.31 551
11.10 25.65 552 10.85 25.14 553 10.40 24.94 554 10.11 24.16 555
10.30 23.22 556 10.01 23.19 557 9.85 22.60 558 8.94 22.71 559 9.08
22.36 560 9.14 21.25 561 8.91 20.57 562 8.48 20.23 563 8.41 19.76
564 8.33 18.95 565 8.13 19.24 566 7.50 18.61 567 7.78 17.66 568
7.69 17.33 569 7.45 17.61 570 7.12 17.31 571 6.95 17.03 572 6.82
16.17 573 6.63 16.20 574 6.43 15.86 575 6.71 15.62 576 6.40 15.06
577 6.37 14.35 578 6.13 14.40 579 6.28 14.51 580 6.08 13.72 581
5.51 13.78 582 5.54 13.23 583 5.53 13.24 584 5.29 13.22 585 5.72
12.35 586 5.00 12.14 587 4.98 12.07 588 4.82 11.48 589 4.81 12.04
590 4.79 11.35 591 4.52 11.28 592 4.46 10.10 593 4.32 10.52 594
4.28 10.09 595 3.88 9.88 596 4.10 9.57 597 4.18 9.47 598 3.96 9.79
599 3.80 9.14 600 3.78 8.88 601 3.67 8.30 602 3.43 8.49 603 3.49
7.82 604 3.28 7.81 605 3.13 7.45 606 3.02 7.76 607 3.29 7.62 608
3.43 7.53 609 2.84 7.36 610 2.95 7.37 611 2.87 6.67 612 2.72 6.99
613 2.64 6.74 614 2.52 6.59 615 2.52 6.29 616 2.60 6.30 617 2.56
6.07 618 2.24 5.60 619 2.74 5.61 620 2.47 5.92 621 2.19 5.51 622
2.03 5.41 623 2.37 5.22 624 2.09 5.13 625 1.75 5.14 626 1.71 4.92
627 2.15 5.04 628 1.93 5.05 629 1.72 4.74 630 2.01 4.89 631 1.66
4.58 632 1.95 4.53 633 1.55 4.44 634 2.03 4.36 635 1.58 4.14 636
2.00 3.74 637 1.52 3.30 638 1.32 3.85 639 1.23 3.82 640 1.77 4.04
641 1.55 3.56 642 1.67 3.38 643 1.22 4.22 644 0.91 3.78 645 1.64
3.38 646 1.23 3.97 647 1.51 3.16 648 1.53 3.30 649 1.41 3.55 650
1.29 2.64 651 1.47 3.08 652 1.35 2.82 653 1.22 2.66 654 1.13 3.13
655 1.33 2.87 656 1.26 3.11 657 1.08 2.09 658 1.33 2.52 659 0.98
2.46 660 1.11 2.75 661 1.19 2.34 662 1.06 2.20 663 1.07 2.86 664
1.08 2.43 665 1.10 2.58 666 1.22 2.34 667 0.94 2.20 668 1.20 2.27
669 0.71 2.07 670 1.31 1.99 671 0.43 2.20 672 0.81 1.48 673 0.84
1.90 674 0.91 2.07 675 0.39 1.79 676 0.82 2.07 677 1.05 1.47 678
1.13 2.14 679 1.20 1.85 680 0.68 1.99 681 0.81 1.50 682 0.30 1.87
683 1.03 1.52 684 1.03 2.16 685 0.50 1.90 686 1.02 1.91 687 0.67
1.58 688 0.65 1.51 689 0.51 1.43 690 0.44 0.97 691 0.79 1.73 692
0.93 1.19 693 0.94 1.40 694 0.84 1.35 695 0.66 1.36 696 0.99 1.20
697 0.73 0.89 698 0.48 1.71 699 0.68 1.29 700 0.43 1.74 701 0.58
1.96 702 0.70 1.07 703 0.78 1.19 704 0.69 1.35 705 0.95 1.17 706
-0.49 1.69 707 1.10 1.38 708 0.68 1.76 709 0.61 1.09 710 0.71 0.90
711 0.54 1.03 712 0.09 1.59 713 0.18 1.59 714 1.18 0.75 715 0.83
0.84 716 0.28 1.45 717 0.39 1.22 718 0.51 0.53 719 -0.22 1.01 720
0.36 1.35 721 0.37 0.90 722 0.00 0.13 723 0.65 1.08 724 0.93 1.09
725 1.22 0.70 726 1.08 0.28 727 -0.67 0.84 728 0.40 0.56 729 0.40
1.81 730 1.33 0.14 731 -0.13 1.12 732 0.81 0.84 733 -0.83 1.29 734
-0.28 1.63 735 0.60 0.47 736 -0.63 0.81 737 0.16 0.34 738 0.68 1.58
739 0.35 2.00 740 -0.90 1.68 741 0.37 1.34 742 0.00 -0.99 743 -0.59
0.40 744 0.20 1.04 745 0.60 2.53
746 -1.04 1.07 747 -0.62 1.32 748 -0.42 1.54 749 -0.21 0.00 750
-0.42 0.66 751 1.30 0.46 752 0.87 -0.23 753 0.00 0.46 754 0.22 0.70
755 -0.46 0.48 756 1.63 1.23 757 0.00 2.24 758 0.24 -0.25 759 0.00
0.75 760 1.92 -1.02 761 -0.24 2.00 762 -0.47 2.65 763 2.18 1.61 764
0.43 0.67 765 0.87 -0.45 766 0.45 0.95 767 -0.24 1.52 768 0.00 1.90
769 0.55 -0.28 770 -0.58 0.30 771 -0.90 0.62 772 0.31 1.27 773 1.57
0.97 774 0.96 0.34 775 -0.64 0.34 776 0.65 -1.03 777 0.32 -1.72 778
-1.64 -0.69 779 -0.68 1.75 780 0.34 1.73 781 -1.71 0.00 782 0.35
3.25 783 0.00 0.36 784 0.00 0.73 785 2.13 -1.12 786 1.43 0.74 787
1.06 0.00 788 0.70 0.00 789 2.76 0.73 790 1.41 3.24 791 1.05 -0.37
792 -0.36 0.00 793 -0.71 2.27 794 -1.46 3.03 795 0.73 1.12 796
-0.36 0.74 797 0.37 -1.11 798 -1.08 0.74 799 1.09 1.14 800 -0.37
1.88
[0056] The spectrum obtained from fluorescence spectroscopy is
wavelength vs. absorption unit. The FSMI is then calculated by
taking the sum of each absorbance unit at each wavelength (integer)
and then dividing by 1000.
[0057] Applying equation (1), FSMI for the oil "AM" under
investigation was calculated to be 15.639. The FSMI for all of the
oils shown in FIG. 1 was similarly calculated, and is shown in
Table 5, below.
TABLE-US-00005 TABLE 5 AM AH L1 SSL XSL UR BI IHI MB API 28.8 27.4
30.3 30.2 36.8 31.6 30.8 30.0 19.6 Gravity, .degree. FSMI 15.639
32.086 38.436 11.951 37.938 50.243 38.549 42.667 34.691
[0058] Applying equation (3) and the constants from Table 3, for
the oil "AM" under review:
Cetane Number GO ( CET ) = K CET + X 1 CET * DEN + X 2 CET * DEN 2
+ X 3 CET * DEN 3 + X 4 CET * FSMI + X 5 CET * FSMI 2 + X 6 CET *
FSMI 3 + X 7 CET * DEN * FSMI = ( - 2.920657 E + 04 ) + ( 8.247657
E + 04 ) ( 0.8828 ) + ( - 8.008823 E + 04 ) ( 0.8828 ) 2 + (
2.758504 E + 04 ) ( 0.8828 ) 3 + ( 1.273387 E + 02 ) ( 15.369 ) + (
4.207752 E - 01 ) ( 15.369 ) 2 + ( - 4.676128 E - 03 ) ( 15.369 ) 3
+ ( - 1.581570 E + 02 ) ( 0.8828 ) ( 15.369 ) = 59 ##EQU00002##
Pour Point GO ( PP ) = K PP + X 1 PP * DEN + X 2 PP * DEN 2 + X 3
PP * DEN 3 + X 4 PP * FSMI + X 5 PP * FSMI 2 + X 6 PP * FSMI 3 + X
7 PP * DEN * FSMI = ( - 2.283807 E + 04 ) + ( 6.995129 E + 04 ) (
0.8828 ) + ( - 7.232753 E + 04 ) ( 0.8828 ) 2 + ( 2.532512 E + 04 )
( 0.8828 ) 3 + ( 4.791017 E + 01 ) ( 15.369 ) + ( - 8.303909 E - 02
) ( 15.369 ) 2 + ( 7.142002 E - 04 ) ( 15.369 ) 3 + ( - 5.156225 E
+ 01 ) ( 0.8828 ) ( 15.369 ) = - 10 ##EQU00002.2## Cloud Point GO (
CP ) = K CP + X 1 CP * DEN + X 2 CP * DEN 2 + X 3 CP * DEN 3 + X 4
CP * FSMI + X 5 CP * FSMI 2 + X 6 CP * FSMI 3 + X 7 CP * DEN * FSMI
= ( 8.016178 E + 04 ) + ( - 2.781445 E + 05 ) ( 0.8828 ) + (
3.199487 E + 05 ) ( 0.8828 ) 2 + ( - 1.219746 E + 05 ) ( 0.8828 ) 3
+ ( 3.108188 E + 01 ) ( 15.369 ) + ( 1.963374 E - 01 ) ( 15.369 ) 2
+ ( - 1.983566 E - 03 ) ( 15.369 ) 3 + ( - 4.212763 E + 01 ) (
0.8828 ) ( 15.369 ) = - 10 ##EQU00002.3## Aniline Point GO ( AP ) =
K AP + X 1 AP * DEN + X 2 AP * DEN 2 + X 3 AP * DEN 3 + X 4 AP *
FSMI + X 5 AP * FSMI 2 + X 6 AP * FSMI 3 + X 7 AP * DEN * FSMI = (
- 4.370054 E + 04 ) + ( 1.44982 E + 05 ) ( 0.8828 ) + ( - 1.608909
E + 05 ) ( 0.8828 ) 2 + ( 5.979962 E + 04 ) ( 0.8828 ) 3 + (
2.649713 E + 01 ) ( 15.369 ) + ( - 5.686953 E - 02 ) ( 15.369 ) 2 +
( 3.346494 E - 04 ) ( 15.369 ) 3 + ( - 2.749938 E + 01 ) ( 0.8828 )
( 15.369 ) = 66 ##EQU00002.4## Aromaticity WCO ( AROM ) = K AROM +
X 1 AROM * DEN + X 2 AROM * DEN 2 + X 3 AROM * DEN 3 + X 4 AROM *
FSMI + X 5 AROM * FSMI 2 + X 6 AROM * FSMI 3 + X 7 AROM * DEN *
FSMI = ( 1.047903 E + 04 ) + ( - 4.741776 E + 04 ) ( 0.8828 ) + (
6.274074 E + 04 ) ( 0.8828 ) 2 + ( - 2.516125 E + 04 ) ( 0.8828 ) 3
+ ( 8.586987 E + 01 ) ( 15.369 ) + ( 6.843602 E - 01 ) ( 15.369 ) 2
+ ( - 7.078907 E - 03 ) ( 15.369 ) 3 + ( - 1.207479 E + 02 ) (
0.8828 ) ( 15.369 ) = 20 ##EQU00002.5## Octane Number ( ON ) = K ON
+ X 1 ON * DEN + X 2 ON * DEN 2 + X 3 ON * DEN 3 + X 4 ON * FSMI +
X 5 ON * FSMI 2 + X 6 ON * FSMI 3 + X 7 ON * DEN * FSMI = (
8.202192 E + 05 ) + ( - 2.845858 E + 06 ) ( 0.8828 ) + ( 3.290683 E
+ 06 ) ( 0.8828 ) 2 + ( - 1.268002 E + 06 ) ( 0.8828 ) 3 + ( -
1.182558 E + 01 ) ( 15.369 ) + ( 2.582860 E - 00 ) ( 15.369 ) 2 + (
- 1.277980 E - 01 ) ( 15.369 ) 3 + ( 0 ) ( 0.8828 ) ( 15.369 ) = 52
##EQU00002.6##
[0059] Accordingly, as shown in the above example, indicative
properties including cetane number, pour point, cloud point,
aniline point, and aromaticity can be assigned to the crude oil
samples without fractionation/distillation (crude oil assays).
[0060] 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.
[0061] 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
U.S.P.Q.2d 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 Nuijten, 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.
[0062] 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.
* * * * *