U.S. patent application number 14/987802 was filed with the patent office on 2016-07-07 for characterization of crude oil and its fractions by fourier transform infrared spectroscopy (ftir) analysis.
The applicant listed for this patent is Saudi Arabian Oil Company. Invention is credited to Adnan Al-Hajji, Amer A. Al-Tuwailib, Omer Refa Koseoglu.
Application Number | 20160195507 14/987802 |
Document ID | / |
Family ID | 55310898 |
Filed Date | 2016-07-07 |
United States Patent
Application |
20160195507 |
Kind Code |
A1 |
Koseoglu; Omer Refa ; et
al. |
July 7, 2016 |
CHARACTERIZATION OF CRUDE OIL AND ITS FRACTIONS BY FOURIER
TRANSFORM INFRARED SPECTROSCOPY (FTIR) 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
Fourier transform infrared spectroscopy (FTIR) of a sample of the
crude oil.
Inventors: |
Koseoglu; Omer Refa;
(Dhahran, SA) ; Al-Hajji; Adnan; (Dhahran, SA)
; Al-Tuwailib; Amer A.; (Dhahran, SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Saudi Arabian Oil Company |
Dhahran |
|
SA |
|
|
Family ID: |
55310898 |
Appl. No.: |
14/987802 |
Filed: |
January 5, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62099679 |
Jan 5, 2015 |
|
|
|
Current U.S.
Class: |
250/301 |
Current CPC
Class: |
G01N 2021/3595 20130101;
G01N 33/2841 20130101; G01N 33/2823 20130101; G01N 21/3577
20130101 |
International
Class: |
G01N 33/28 20060101
G01N033/28; G01N 21/3577 20060101 G01N021/3577 |
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 naptha or gas oil
fraction, the system comprising: a Fourier transform infrared
spectrophotometer; a non-volatile memory device that stores
calculation modules and data, the data including density of the
crude oil sample and Fourier transform infrared spectroscopy data
indicative of transmittance values at predetermined increments
between a predetermined range for the crude oil sample, the data
derived from an analysis of the crude oil by the Fourier transform
infrared spectrophotometer; a processor coupled to the non-volatile
memory; a first calculation module that retrieves the Fourier
transform infrared spectroscopy data from the non-volatile memory,
that calculates a crude oil Fourier transform infrared spectroscopy
index value of the fraction from the transmittance values of the
spectroscopy data, and that transfers the calculated Fourier
transform infrared spectroscopy index into the non-volatile memory;
and a second calculation module that calculates the indicative
property for the 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
Fourier transform infrared 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
Fourier transform infrared spectroscopy analyzer is 20-80.degree.
C.
9. The system of claim 1, wherein the Fourier transform infrared
spectroscopy index is that of whole crude oil.
10. The system of claim 1, wherein the Fourier transform infrared
spectroscopy index is calculated from FTIR data measured in the
wavelength range of 700-4000 cm.sup.-1.
11. The system of claim 1, wherein the Fourier transform infrared
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 naptha or gas oil
fraction, the method comprising; obtaining the density of the crude
oil sample; providing a Fourier transform infrared
spectrophotometer; subjecting said crude oil sample to Fourier
transform infrared spectroscopic analysis using the Fourier
transform infrared spectrophotometer and entering measured
transmittance values into non-volatile memory of a computer; using
a processor of the computer to calculate a crude oil Fourier
transform infrared spectroscopy index value of fraction from the
transmittance values; and using the processor to calculate and
record into the non-volatile memory the indicative property for the
naptha 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 Fourier
transform infrared 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
Fourier transform infrared spectroscopy analyzer is 20-80.degree.
C.
20. The method of claim 12, wherein the Fourier transform infrared
spectroscopy index is that of whole crude oil.
21. The method of claim 12, wherein the Fourier transform infrared
spectroscopy index is calculated from FTIR data measured in the
wavelength range of 700-4000 cm.sup.-1.
22. The method of claim 12, wherein the Fourier transform infrared
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. 62/099,679 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 Fourier
transform infrared spectroscopy (FTIR) 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 %.
[0005] 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.
[0006] 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+
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] Fourier transform infrared spectroscopy (FTIR) is an
analytical technique used to measure the absorbance or
transmittance of light by a solid, liquid or gas sample at various
wavelengths, producing an FTIR spectrum. The peaks correspond to
the frequencies of vibrations of the bonds of the atoms making up
the material as the sample molecules selectively absorb radiation
of specific wavelengths. The FTIR spectrum represents the molecular
vibrational spectrum of the sample, providing a fingerprint of the
composition of the material under testing. Hence, the FTIR spectrum
is characteristic of the structure of the molecule and can be used
for identification (qualitative analysis). FTIR is also a good
monitoring tool for chemical reactions where functional information
about a specific chemical can be obtained. Since the spectrum peak
size is a direct indication of the amount of the material, FTIR can
also be used for quantitative analysis. The commonly used region
for infrared absorption fluorescence spectroscopy is approximately
4000-400 cm.sup.-1 because most organic compounds absorb IR
radiation within this region.
[0017] This invention discloses a system and method in which FTIR
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.
[0018] 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
[0019] 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 naptha fraction, and the aromaticity for the whole crude oil
(WCO), are assigned as a function of density and FTIR 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
[0020] 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:
[0021] FIG. 1 is a graphic plot of typical FTIR data for typical
crude oil samples with different API gravities;
[0022] FIG. 2 is a block diagram of a method in which an embodiment
of the invention is implemented;
[0023] FIG. 3 is a schematic block diagram of modules of an
embodiment of the invention; and
[0024] FIG. 4 is a block diagram of a computer system in which an
embodiment of the invention is implemented.
DETAILED DESCRIPTION OF INVENTION
[0025] 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 FTIR 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.
[0026] 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.
[0027] In the system and method herein, FTIR analysis is obtained
by a suitable known or to-be-developed process. Fourier transform
infrared spectroscopy uses an FTIR spectrophotometer to
simultaneously collect spectral data of a solid, liquid, or gas
over a wide spectral range. A Fourier transform is employed to
convert the raw data into the actual spectrum. The method confers a
significant advantage over a dispersive spectrophotometer that
measures intensity over a narrow range of wavelengths at a
time.
[0028] In one embodiment, a Varian 660-IR (FTIR) spectrophotometer
equipped with a Specac's Golden Gate ATR accessory with a diamond
crystal was used for the analysis of the crude oil. The background
FTIR run was taken against a clean accessory. For sample analysis,
three drops of crude oil were placed on the diamond crystal and the
crystal was covered with a plastic cap to minimize sample
evaporation. The instrument was then scanned over the wavelength
range from 4000-700 CM.sup.-1.
[0029] Typical Fourier transform infrared spectroscopy data for
crude oils with different API gravities are shown in FIG. 1.
[0030] In one embodiment, the FTIR index is calculated as follows.
The maximum transmittances (maxtrans) are determined for each of a
number of crude oils under investigation.
FTIRI.sub.desired crude=maxtrans.sub.desired
crude-maxtrans.sub.lowest value (1);
[0031] 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 FTIR according to the method 200 described
below.
[0032] In step 210 a sample of three drops of crude oil is placed
via a pipette on the diamond crystal and the crystal was covered
with a plastic cap to minimize sample evaporation. No sample
dilution or special sample preparation is required. The instrument
was then scanned over the wavelength range from 4000-700
CM.sup.-1.
[0033] In step 215, the FTIR data is arranged so that maximum
transmittances are determined.
[0034] In step 220, an FTIR index (FTIRI) is calculated according
to equation (1).
[0035] 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
FTIRI of crude oil.
[0036] That is,
Indicative Property=f(density.sub.crude oil,FTIRI.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*FTIRI+X5*FTIRI.sup.2+X6*FT-
IRI.sup.3+X7*DEN*FTIRI (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 FTIR.
[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 Fourier transform infrared fluorescence
spectroscopy data derived from the crude oil.
[0043] FTIR index calculation module 315 calculates the Fourier
transform infrared spectroscopy index from the FTIR 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 Fourier transform infrared 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 Fourier
transform infrared 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
Fourier transform infrared 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 Fourier transform infrared 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 Fourier transform
infrared 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 Fourier transform infrared 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, Fourier transform infrared 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 Aniline Point K 1.353576E+05 1.099007E+05 5.550384E+04
7.717846E+04 X1 -4.652678E+05 -3.752190E+05 -1.896601E+05
-2.654884E+05 X2 5.312307E+05 4.267904E+05 2.162203E+05
3.033093E+05 X3 -2.013982E+05 -1.617556E+05 -8.225676E+04
-1.149909E+05 X4 1.946958E+02 2.197450E+01 -1.600659E+01
1.402683E+02 X5 -3.773736E+00 -1.151301E+00 -7.195605E-02
-2.699202E+00 X6 1.955737E-01 5.885146E-02 4.288102E-03
1.364182E-01 X7 -2.042985E+02 -1.901277E+01 1.848965E+01
-1.466497E+02 Constants Octane Number WCO-AROM K 8.202192E+05
-2.937030E+04 X1 -2.845858E+06 1.041119E+05 X2 3.290683E+06
-1.218370E+05 X3 -1.268002E+06 4.713092E+04 X4 -1.182558E+01
-6.655481E+01 X5 2.582860E+00 -6.705168E-01 X6 -1.277980E-01
3.361324E-02 X7 0.0000000E+00 7.911532E+01
[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/l was analyzed by
FTIR, using the described method. The tabulated results follow in
Table 4:
TABLE-US-00004 TABLE 4 Crude Oils API = 28.8.degree. API =
19.6.degree. WL, cm.sup.-1 Transmission, % Transmission, % 700
97.38 95.14 720 93.42 94.27 740 93.87 91.75 760 95.20 94.14 780
96.86 94.52 800 96.81 93.76 820 97.04 93.86 840 98.72 95.07 860
98.88 95.04 880 98.18 94.73 900 99.89 95.96 920 99.89 96.65 940
100.72 96.08 960 100.26 96.58 980 100.36 96.30 1000 100.40 96.62
1020 99.95 96.95 1040 99.92 96.54 1060 100.11 96.72 1080 100.47
96.77 1100 100.56 97.24 1120 100.74 97.09 1140 100.14 97.01 1160
99.74 96.42 1180 100.50 96.60 1200 100.73 96.92 1220 100.88 96.24
1240 99.95 96.16 1260 100.24 96.20 1280 99.62 95.67 1300 99.35
95.46 1320 99.34 95.52 1340 99.51 95.05 1360 98.34 93.83 1380 92.60
88.37 1400 100.42 96.27 1420 100.41 95.22 1440 92.28 87.02 1460
83.72 79.45 1480 98.74 94.53 1500 101.28 97.10 1520 104.46 98.58
1540 105.33 98.85 1560 104.49 98.59 1580 101.55 97.60 1600 100.85
96.54 1620 102.64 97.44 1640 102.65 98.14 1660 102.91 98.54 1680
103.58 98.80 1700 104.79 98.97 1720 103.61 99.16 1740 103.36 99.25
1760 102.80 99.27 1780 103.07 99.52 1800 103.25 99.50 1820 102.39
99.49 1840 102.49 99.37 1860 102.40 99.52 1880 102.12 99.43 1900
102.29 99.28 1920 102.88 99.65 1940 102.53 99.64 1960 102.07 99.50
1980 102.72 99.58 2000 102.27 99.08 2020 102.38 99.63 2040 102.98
99.95 2060 102.03 99.41 2080 102.45 99.29 2100 102.08 99.12 2120
102.54 99.13 2140 102.68 99.74 2160 102.07 99.99 2180 102.55 99.17
2200 101.50 99.74 2220 103.54 98.91 2240 102.41 99.26 2260 102.41
99.77 2280 102.08 99.34 2300 102.58 99.11 2320 105.38 99.28 2340
106.71 99.76 2360 108.80 99.58 2380 103.61 99.44 2400 102.07 99.09
2420 102.35 99.09 2440 102.22 99.08 2460 101.84 99.00 2480 102.23
99.11 2500 101.78 99.43 2520 101.85 98.76 2540 102.28 99.18 2560
102.03 98.94 2580 101.85 99.16 2600 102.04 98.94 2620 102.00 98.83
2640 101.71 98.64 2660 101.56 98.73 2680 101.46 98.43 2700 101.45
98.89 2720 101.28 98.09 2740 101.53 98.48 2760 101.64 98.65 2780
101.77 98.47 2800 101.00 97.70 2820 99.78 95.76 2840 88.18 83.12
2860 76.69 73.72 2880 86.13 81.10 2900 76.59 71.62 2920 56.50 56.75
2940 78.17 72.96 2960 80.38 77.30 2980 97.61 93.36 3000 101.06
97.51 3020 101.07 97.58 3040 101.22 98.28 3060 102.62 99.05 3080
102.20 99.12 3100 101.82 98.70 3120 102.30 98.86 3140 102.85 98.91
3160 102.85 97.72 3180 103.05 99.53 3200 103.77 99.32 3220 102.97
100.13 3240 103.45 99.20 3260 103.39 99.53 3280 103.04 98.35 3300
102.86 99.59 3320 102.41 99.93 3340 102.48 99.45 3360 102.25 98.99
3380 103.11 99.48 3400 103.62 99.49 3420 102.99 99.70 3440 103.46
99.99 3460 102.48 99.40 3480 103.48 99.28 3500 103.29 99.63 3520
103.65 99.14 3540 103.55 99.24 3560 102.41 98.82 3580 104.15 99.61
3600 105.09 99.50 3620 104.65 99.43 3640 103.48 99.72 3660 103.25
100.49 3680 102.93 99.85 3700 103.40 99.81 3720 103.49 98.98 3740
104.42 99.77 3760 103.62 99.76 3780 103.66 99.61 3800 104.76 99.75
3820 104.37 100.06 3840 103.63 99.56 3860 103.66 99.58 3880 103.76
99.70 3900 103.83 99.77 3920 102.74 99.49 3940 102.52 99.57 3960
102.40 99.92 3980 102.11 99.59 4000 102.09 99.61
[0056] As noted in equation (1), FTIRI is calculated by comparing
the maximum transmittances for a number of crude oils under
investigation. In the example above, for a crude oil designated
"AM," the maximum transmittance maxtrans.sub.AM=108.797. The
minimum value of these maximum transmittances is that for the crude
oil designated "IHI," for which maxtrans.sub.IHI=94.935.
[0057] Similar FTIR data was obtained for a number of other oils,
with the maximum transmittances shown in Table 5, below. As can be
seen, the lowest of the maximum transmittance is found for the oil
designated "IHI," which has a maximum transmittance of 94.935.
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. maxtrans
108.797 101.530 100.691 102.154 105.794 107.708 108.144 94.935
101.448 FTIRI 13.862 6.595 5.756 7.219 10.858 12.773 13.209 0.000
6.512
[0058] Applying equation (1), FTIRI for the oil "AM" under
investigation was calculated to be:
FTIRI=[maxtrans.sub.AM]-[min-of-maxtrans], so FTIRI for AM Crude is
[108.797]-[94.935]=13.862
[0059] Applying equation (3) and the constants from Table 3:
Cetane
Number.sub.GO(CET)=K.sub.CET+X1.sub.CET*DEN+X2.sub.CET*DEN.sup.2+-
X3.sub.CET*DEN.sup.3+X4.sub.CET*FTIRI+X5.sub.CET*FTIRI.sup.2+X6.sub.CET*FT-
IRI.sup.3+X7.sub.CET*DEN*FTIRI=(1.353576E+05)+(-4.652678E+05)(0.8828)+(5.3-
12307E+05)(0.8828).sup.2+(-2.013982E+05)(0.8828).sup.3+(1.946958E+02)(13.8-
62)+(-3.773736E+00)(13.862).sup.2+(1.955737E-01)(13.862).sup.3+(-2.042985E-
+02)(0.8828)(13.862)=59
Pour
Point.sub.GO(PP)=K.sub.PP+X1.sub.PP*DEN+X2.sub.PP*DEN.sup.2+X3.sub.-
PP*DEN.sup.3+X4.sub.PP*FTIRI+X5.sub.PP*FTIRI.sup.2+X6.sub.PP*FTIRI.sup.3+X-
7.sub.PP*DEN*FTIRI=(1.099007E+05)+(-3.752190E+05)(0.8828)+(4.267904E+05)(0-
.8828).sup.2+(-1.617556E+05)(0.8828).sup.3+(2.197450E+01)(13.862)+(-1.1513-
01E+00)(13.862).sup.2+(5.885146E-02)(13.862).sup.3+(-1.901277E+01)(0.8828)-
(13.862)=-10
Cloud
Point.sub.GO(CP)=K.sub.CP+X1.sub.CP*DEN+X2.sub.CP*DEN.sup.2+X3.sub-
.CP*DEN.sup.3+X4.sub.CP*FTIRI+X5.sub.CP*FTIRI.sup.2+X6.sub.CP*FTIRI.sup.3+-
X7.sub.CP*DEN*FTIRI=(5.550384E+04)+(-1.896601E+05)(0.8828)+(2.162203E+05)(-
0.8828).sup.2+(-8.225676E+04)(0.8828).sup.3+(-1.600659E+01)(13.862)+(-7.19-
5605E-02)(13.862).sup.2+(4.288102E-03)(13.862).sup.3+(1.848965E+01)(0.8828-
)(13.862)=-10
Aniline
Point.sub.GO(AP)=K.sub.AP+X1.sub.AP*DEN+X2.sub.AP*DEN.sup.2+X3.s-
ub.AP*DEN.sup.3+X4.sub.AP*FTIRI+X5.sub.AP*FTIRI.sup.2+X6.sub.AP*FTIRI.sup.-
3+X7.sub.AP*DEN*FTIRI=(7.717846E+04)+(-2.654884E+05)(0.8828)+(3.033093E+05-
)(0.8828).sup.2+(-1.149909E+05)(0.8828).sup.3+(1.402683E+02)(13.862)+(-2.6-
99202E+00)(13.862).sup.2+(1.364182E-01)(13.862).sup.3+(-1.466497E+02)(0.88-
28)(13.862)=66
Aromaticity.sub.WCO(AROM)=K.sub.AROM+X1.sub.AROM*DEN+X2.sub.AROM*DEN.sup-
.2+X3.sub.AROM*DEN.sup.3+X4.sub.AROM*FTIRI+X5.sub.AROM*FTIRI.sup.2+X6.sub.-
AROM*FTIRI.sup.3+X7.sub.AROM*DEN*FTIRI=(-2.937030E+04)+(1.041119E+05)(0.88-
28)+(-1.218370E+05)(0.8828).sup.2+(4.713092E+04)(0.8828).sup.3+(-6.655481E-
+01)(13.862)+(-6.705168E-01)(13.862).sup.2+(3.361324E-02)(13.862).sup.3+(7-
.911532E+01)(0.8828)(13.862)=20
Octane
Number(ON)=K.sub.ON+X1.sub.ON*DEN+X2.sub.ON*DEN.sup.2+X3.sub.ON*D-
EN.sup.3+X4.sub.ON*FTIRI+X5.sub.ON*FTIRI.sup.2+X6.sub.ON*FTIRI.sup.3+X7.su-
b.ON*DEN*FTIRI=(8.202192E+05)+(-2.845858E+06)(0.8828)+(3.290683E+06)(0.882-
8).sup.2+(-1.268002E+06)(0.8828).sup.3+(-1.182558E+01)(13.862)+(2.582860E+-
00)(13.862).sup.2+(-1.277980E-01)(13.862).sup.3+(0)(0.8828)(13.862)=52
[0060] 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).
[0061] 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.
[0062] 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.
[0063] 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.
* * * * *