METHOD TO PREPARE VIRTUAL ASSAY USING LASER INDUCED FLUORESCENCE SPECTROSCOPY

Abstract

Systems and methods are disclosed for providing virtual assays of an oil sample such as crude oil based on laser induced fluorescence spectroscopy carried out on the oil sample, and the density of the oil sample. The virtual assay provides a full range of information about fractions of the oil sample including naphtha, gas oil, vacuum gas oil, vacuum residue, and other information about the properties of the oil sample. Using the system and method herein, the virtual assay data pertaining to these several fractions of the oil sample and the oil sample itself are obtained without fractionation of the oil sample into the several components.

Description

RELATED APPLICATIONS

Not applicable.

BACKGROUND

Field of the Invention

The present invention relates to methods and systems for evaluating an oil sample such as crude oil to provide a virtual assay.

Description of Related Art

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. In addition to crude oils varying from one geographical region to another and from field to field, it has also been observed that the properties of the crude oil from one field may change with time, as oil is withdrawn from different levels or areas of the field. Depending on the source and/or time of withdrawal, 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.

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.

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. Common fractions and their corresponding nominal boiling points or boiling point ranges are given in Table 1.

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.

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. 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 (for instance having a nominal boiling point range of about 36-180° C.), kerosene (for instance having a nominal boiling point range of about 180-240° C.), gas oil (for instance having a nominal boiling point range of about 240-370° C.) and atmospheric residue (for instance having a nominal boiling point range of about >370° 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 (for instance having a nominal boiling point range of about 370-520° C.) and vacuum residue (for instance having a nominal boiling point range of about >520° C.). Crude assay data is conventionally obtained from individual analysis of these cuts, separately for each type of data sought for the assay (that is, elemental composition, physical property and indicative property), 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.

Whole Crude Oil Properties

Many properties are routinely measured for crudes. Some of the most common factors affecting crude oil handling, processing, and value include the following: density; viscosity; pour point; Reid vapor pressure (RVP); carbon residue; sulfur; nitrogen; metals; salt content; hydrogen sulfide; Total Acidity Number (TAN). These are described in more detail below:

• Density, measured for example by the ASTM D287 method, is the weight of a substance for a given unit of volume. Density of crude oil or crude products is measured as specific gravity comparing the density of the crude or product to the density of water (usually expressed as gm/cc) or API gravity (°API or degrees API).
• Viscosity, measured for example by the ASTM D 445 method, is the measure of the resistance of a liquid to flow, thereby indicating the pumpability of the oil. Kinematic viscosity is the viscosity of the material divided by the density (specific gravity) of the material at the temperature of viscosity measurement; kinematic viscosity is commonly measured in stokes (St) or centistokes (cSt).
• Pour point, measured for example by the ASTM D97 method, is the temperature, to the next 5° F. increment, above which an oil or distillate fuel becomes solid. The pour point is also the lowest temperature, in 5° F. increments, at which the fluid will flow. After preliminary heating, the sample is cooled at a specified rate and examined at intervals of 3° C. for flow characteristics. The lowest temperature at which movement of the specimen is observed is recorded as the pour point.
• Reid vapor pressure (RVP), measured for example by the ASTM D323 method, is the measure of the vapor pressure exerted by an oil, mixed with a standard volume ratio of air, at 100° F. (38° C.).
• Carbon residue, measured for example by the ASTM D189, D4536 methods, is the percentage of carbon by weight for coke, asphalt, and heavy fuels found by evaporating oil to dryness under standard laboratory conditions. Carbon residue is generally termed Conradson Carbon Residue, or CCR.
• Sulfur is the percentage by weight, or in parts per million by weight, of total sulfur contained in a liquid hydrocarbon sample. Sulfur must be removed from refined product to prevent corrosion, protect catalysts, and prevent environmental pollution. Sulfur is measured, for example, by ASTM D4294, D2622, D5453 methods for gasoline and diesel range hydrocarbons.
• Nitrogen, measured for example by the ASTM D4629, D5762 methods, is the weight in parts per million, of total nitrogen contained in a liquid hydrocarbon sample. Nitrogen compounds are also catalyst poisons.
• Various metals (arsenic, lead, nickel, vanadium, etc.) in a liquid hydrocarbon are potential process catalyst poisons. They are measured by Induced Coupled Plasma and/or Atomic Absorption Spectroscopic methods, in ppm.
• Salt is measured, for example, by the ASTM D3230 method and is expressed as pounds of salt (NaCl) per 1000 barrels of crude. Salts are removed prior to crude oil distillation to prevent corrosion and catalyst poisoning.
• Hydrogen sulfide (H₂S) is a toxic gas that can be evolved from crude or products in storage or in the processing of crude. Hydrogen sulfide dissolved in a crude stream or product stream is measured in ppm.
• Total acidity is measured, for example, by the ASTM methods, D664, D974, and is a measure of the acidity or alkalinity of an oil. The number is the mass in milligrams of the amount of acid (HCl) or base (KOH) required to neutralize one gram of oil.

These properties affect the transportation and storage requirements for crudes, define the products that can be extracted under various processing schemes, and alert us to safety and environmental concerns. Each property can also affect the price that the refiner is willing to pay for the crude. In general, light, low sulfur crudes are worth more than heavy, high sulfur crudes because of the increased volume of premium products (gasoline, jet fuel, and diesel) that are available with minimum processing.

Crude Assays

A crude assay is a set of data that defines crude composition and properties, yields, and the composition and properties of fractions. Crude assays are the systematic compilation of data defining composition and properties of the whole crude along with yields and composition and properties of various boiling fractions. For example, a conventional assay method requires approximately 20 liters of crude oil be transported to a laboratory, which itself can be time-consuming and expensive, and then distilled to obtain the fractions and then have analysis performed on the fractions. This systematic compilation of data provides a common basis for the comparison of crudes. The consistent presentation of data allows us to make informed decisions as to storage and transportation needs, processing requirements, product expectations, crude relative values, and safety and environmental concerns. It also allows us to monitor crude quality from a single individual source over a period of time.

Crude oils or fractions are evaluated and compared using some of the key properties that are indicative of their performance in engines. These are the cetane number, the cloud point, the pour point (discussed above), the aniline point, and the flash point. In instances where the crude is suitable for production of gasoline, the octane number is another key property. These are described individually herein.

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.

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° C.

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.

The flash point, determined by ASTM D56, D92, D93 methods, is the minimum temperature at which a fluid will support instantaneous combustion (a flash) but before it will burn continuously (fire point). Flash point is an important indicator of the fire and explosion hazards associated with a petroleum product.

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.

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

Systems and methods are disclosed for providing virtual assays including assigned assay values pertaining to an oil sample subject to analysis, and its fractions, based on data obtained by analytic characterization of the oil sample without fractionation, and the density of the oil sample. The virtual assay of the oil sample provides a full range of information about fractions of the oil sample including naphtha, gas oil, vacuum gas oil, residue, and other information about the properties of the oil sample. This virtual assay is useful for producers, refiners, and marketers to benchmark the oil quality and, as a result, evaluate the oils without performing the customary extensive and time-consuming crude oil assays.

In an embodiment, the present disclosure is directed to a method for producing a virtual assay of an oil sample, wherein the oil sample is characterized by a density, selected from the group consisting of crude oil, bitumen and shale oil, and characterized by naphtha, gas oil, vacuum gas oil and vacuum residue fractions. Laser induced fluorescence (LIF) spectroscopy data, indicative of fluorescence intensity over a predetermined range of wavelengths for the oil sample without distillation, is entered into a computer. An analytical value (AV) is calculated and assigned as a function of the LIF spectroscopy data. Virtual assay data of the oil sample and the naphtha, gas oil, vacuum gas oil and vacuum residue fractions is calculated and assigned as a function of the AV and the density of the oil sample. The virtual assay data comprises a plurality of assigned data values.

In certain embodiments, the virtual assay data comprises: a plurality of assigned assay data values pertaining to the oil sample including one or more of the aromatic content, C5-asphaltenes content, elemental compositions of sulfur and nitrogen, micro-carbon residue content, total acid number and viscosity, a plurality of assigned assay values pertaining to the vacuum residue fraction of the oil sample including one or more of the elemental composition of sulfur and micro-carbon residue content; a plurality of assigned assay values pertaining to the vacuum gas oil fraction of the oil sample including one or both of the elemental compositions of sulfur and nitrogen; a plurality of assigned assay values pertaining to the gas oil fraction of the oil sample including one or more of the elemental compositions of sulfur and nitrogen, viscosity, and indicative properties including aniline point, cetane number, cloud point and/or pour point; and a plurality of assigned assay values pertaining to the naphtha fraction of the oil sample including one or more of the aromatic content, elemental composition of hydrogen and/or sulfur, paraffin content and octane number.

In certain embodiments, the virtual assay data also comprises: yields of fractions from the oil sample as mass fractions of boiling point ranges, including one or more of naphtha, gas oil, vacuum gas oil and vacuum residue; composition information of hydrogen sulfide and/or mercaptans in the oil sample and/or its fractions; elemental compositions of one or more of carbon, hydrogen, nickel, and vanadium; physical properties of the oil sample and/or its fractions including one or more of API gravity and refractive index; and/or indicative properties of the oil sample and/or its fractions including one or more of flash point, freezing point and smoke point.

In certain embodiments, the method further comprises operating a laser induced fluorescence spectroscopy system to obtain fluorescence intensities over the predetermined range of wavelengths as the LIF spectroscopy data, by carrying out spectroscopy on the oil sample directly and without distillation.

In certain embodiments, each assay value is determined by a multi-variable polynomial equation with predetermined constant coefficients developed using linear regression techniques, wherein corresponding variables are the AV and the density of the oil sample.

In an embodiment, the present disclosure is directed to a system for producing a virtual assay of an oil sample, wherein the oil sample is characterized by a density, is selected from the group consisting of crude oil, bitumen and shale oil, and is characterized by naphtha, gas oil, vacuum gas oil and vacuum residue fractions. The system comprises a laser induced fluorescence spectroscopy system that outputs LIF spectroscopy data, a non-volatile memory device, a processor coupled to the non-volatile memory device, and first and second calculation modules that are stored in the non-volatile memory device and that is executed by the processor. The non-volatile memory device stores the first and second calculation modules and data, the data including the LIF spectroscopy data that is indicative of fluorescence intensities over a predetermined range of wavelengths obtained by analysis of the oil sample without distillation. The first calculation module contains suitable instructions to calculate, as a function of the NIR spectroscopy data, an analytical value (AV). The second calculation module contains suitable instructions to calculate, as a function of the AV and the density of the oil sample, a plurality of assigned data values as the virtual assay pertaining to the overall oil sample, and the naphtha, gas oil, vacuum gas oil and vacuum residue fractions of the oil sample.

Still other aspects, embodiments, and advantages of these exemplary aspects and embodiments, are discussed in detail below. Moreover, it is to be understood that both the foregoing information and the following detailed description are merely illustrative examples of various aspects and embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. The accompanying drawings are included to provide illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification. The drawings, together with the remainder of the specification, serve to explain principles and operations of the described and claimed aspects and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is process flow diagram of steps used to implement the method described herein for providing virtual assays of an oil sample such as crude oil based on laser induced fluorescence (LIF) spectroscopy.

FIG. 2 is a graphic plot of LIF spectroscopy data for nine types of crude oil including an oil sample under investigation in the example herein.

FIG. 3 is a process flow diagram of steps used in an example herein to provide a virtual assay of a crude oil sample based on LIF spectroscopy.

FIG. 4 is a block diagram of a component of a system for implementing the invention, according to one embodiment.

DETAILED DESCRIPTION

Systems and methods are disclosed for providing virtual assays of an oil sample such as crude oil based on laser induced fluorescence (LIF) spectroscopy carried out on the oil sample, and the density of the oil sample. The virtual assay provides a full range of information about fractions of the oil sample including naphtha, gas oil, vacuum gas oil, vacuum residue, and other information about the properties of the oil sample. Using the system and method herein, the virtual assay data pertaining to these several fractions of the oil sample and the oil sample itself without fractionation into the several components.

Concerning the naphtha fraction, assigned assay values for the virtual assay include: elemental composition values included in the virtual assay comprise one or more of hydrogen content, aromatic content, paraffin content and sulfur content; and an indicative property included in the virtual assay comprises an octane number. Concerning the gas oil fraction, assigned assay values for the virtual assay include: elemental composition values included in the virtual assay comprise one or more of sulfur content and nitrogen content; physical properties included in the virtual assay comprises viscosity and pour point; and indicative properties included in the virtual assay comprise one or more of aniline point, cetane number and cloud point. Concerning the vacuum gas oil fraction, assigned assay values for the virtual assay include: elemental composition values included in the virtual assay comprise one or more of sulfur content, nitrogen content and micro carbon residue content. Concerning the vacuum residue, assigned assay values for the virtual assay include: elemental composition values included in the virtual assay comprise one or more of sulfur content and micro carbon residue content. Concerning the full range of the oil sample, assigned assay values for the virtual assay include: elemental composition values included in the virtual assay comprise one or more of asphaltene content, sulfur content, nitrogen content and total acids content (total acid number, mg KOH/100g); and physical properties included in the virtual assay comprises viscosity and pour point.

In certain embodiments of the virtual assay provided herein, the “naphtha fraction” refers to a straight run fractions from atmospheric distillation containing hydrocarbons having a nominal boiling range of about 20-205, 20-193, 20-190, 20-180, 20-170, 32-205, 32-193, 32-190, 32-180, 32-170, 36-205, 36-193, 36-190, 36-180 or 36-170° C.; the “gas oil fraction” refers to a straight run fractions from atmospheric distillation containing hydrocarbons having a nominal boiling range of about 170-400, 170-380, 170-370, 170-360, 180-400, 180-380, 180-370, 180-360, 190-400, 190-380, 190-370, 190-360, 193-400, 193-380, 193-370 or 193-360° C.; the “vacuum gas oil fraction” refers to a straight run fractions from vacuum distillation containing hydrocarbons having a nominal boiling range of about 360-565, 360-550, 360-540, 360-530, 360-520, 360-510, 370-565, 370-550, 370-540, 370-530, 370-520, 370-510, 380-565, 380-550, 380-540, 380-530, 380-520, 380-510, 400-565, 400-550, 400-540, 400-530, 400-520 or 400-510° C.; and “vacuum residue” refers to the bottom hydrocarbons from vacuum distillation having an initial boiling point corresponding to the end point of the VGO range hydrocarbons, for example about 510, 520, 530, 540, 550 or 565° C., and having an end point based on the characteristics of the crude oil feed.

The system and method is applicable for naturally occurring hydrocarbons derived from crude oils, bitumens or shale oils, and heavy oils 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, core cuttings, oil well drilling cuttings, stabilizer, extractor, or distillation tower. In certain embodiments system and method is applicable for crude oil, whereby a virtual assay is obtained using the systems and methods herein without the extensive laboratory work required for distillation and analysis of each of the individual fractions.

Referring to FIG. 1, a process flow diagram of steps carried out to obtain a virtual assay 195 is provided. Prior to carrying out the steps outlined in FIG. 1, a set of constants is obtained for each of the elemental composition values / physical properties / indicative properties to be calculated using the process and system disclosed herein to obtain a virtual assay, represented as dataset 105. The set of constants can be developed, for instance by linear regression techniques, based on empirical data of a plurality of crude oil assays and analyses using conventional techniques including distillation and industry-established testing methods to obtain the crude oil assay data. Examples of sets of constants used for calculating assigned assay values to produce the virtual assay 195 based on various analytic characterization techniques are provided herein.

At step 110, the density if the oil sample is provided (steps for obtaining this density are not shown and can be carried out as is known, in certain embodiments a 15° C./4° C. density in units of kilograms per liter using the method described in ASTM D4052); this density value can be stored in memory with other data pertaining to the oil sample, or conveyed directly to the one or more steps as part of the functions thereof. In step 115, if necessary, the oil sample is prepared for a particular analytic characterization technique (shown in dashed lines as optional). In step 120, analytic characterization of the oil sample, or the oil sample prepared as in step 115, without fractionation, is carried out. As a result, analytic characterization data 125 is obtained.

In step 130, the analytic characterization data 125 is used to calculate one or more analytical values 135, which are one common analytical value or a common set of analytical values used in subsequent steps to calculate a plurality of different elemental composition values / physical properties/ indicative properties that make up the virtual assay. In the embodiments herein the one common analytical value or common set of analytical values is an index or plural index values, also referred to as a LIF index or LIFI derived from a summation of fluorescence intensities over a predetermined range of wavelengths, as determined by LIF spectroscopy of the oil sample.

Steps 140, 150, 160, 170 and 180 are used to calculate and assign a plurality of different elemental composition values / physical properties/ indicative properties that make up the virtual assay 195, for each of a total oil sample, a naphtha fraction, a gas oil fraction, a vacuum gas oil fraction and a vacuum residue fraction, respectively. Each of the steps produces corresponding assigned assay values for the virtual assay 195, include including assigned assay values 145 pertaining to the total oil sample, assigned assay values 155 pertaining to a naphtha fraction, assigned assay values 165 pertaining to a gas oil fraction, assigned assay values 175 pertaining to a vacuum gas oil fraction and assigned assay values 185 pertaining to a vacuum residue fraction.

In certain embodiments, the steps are carried out in any predetermined sequence, or in no particular sequence, depending on the procedures in the calculation modules. In certain embodiments, the steps are carried out in parallel. The process herein uses a common analytical value, in conjunction with the set of constants and the density of the oil sample, for each of the assigned assay values (elemental composition values / physical properties / indicative properties) in the given virtual oil sample assay 195 produced at step 190. For instance, each of the steps 140, 150, 160, 170 and 180 are carried in any sequence and/or in parallel out as show using the equations herein for various analytical values or sets of analytical values.

The assigned assay values from each of the fractions and the total oil sample are compiled and presented as a virtual assay 195, which can be, for instance, printed or rendered on a display visible to, or otherwise communicated to, a user to understand the composition and properties of the crude. With the virtual assay 195, users such as customers, producers, refiners, and marketers can benchmark the oil quality. The virtual assay 195 can be used to guide decisions related to an appropriate refinery or refining unit, for processing the oil from which the oil sample is obtained, and/or for processing one or more of the fractions thereof. In addition the assigned assay values including the indicative properties are used to determine the engine/fuel performance or usability or flow characteristic or composition. This can be accomplished using the method and system herein without performing the customary extensive and time-consuming crude oil assays.

The assigned assay values for the virtual assay herein are calculated as a function of one or more analytical values, and the density of the oil sample, as denoted at (1).

$\begin{array}{cc}\text{AD}\text{=}\text{f}\left(\text{ρ},\text{AV}\right)& \text{­­­(1)}\end{array}$

where:

• AD is the assigned assay value (for example a value and/or property representative of an elemental composition value, a physical property or an indicative property); and
• AV is an analytical value of the oil sample, wherein AV can be a single analytical value, or wherein AV can be AV(1)... AV(n) as plural analytical values of the oil sample, wherein n is an integer of 2 or more, in certain embodiments 2, 3 or 4; and
• ρ is the density of the oil sample, in certain embodiments a 15° C./4° C. density in units of kilograms per liter using the method described in ASTM D4052.

According to an embodiment of the system and method described further herein, an analytical value AV is a single value, an index derived from a summation of fluorescence intensities over a predetermined range of wavelengths, as determined by LIF spectroscopy of the oil sample carried out on the oil sample, represented herein as a LIF index, or LIFI. Advantageously, the method and system herein deploy analytical characterization by LIF spectroscopy to carry out analysis of the oil sample without fractionating, obtain an analytical value based on the LIF spectroscopy analysis of the oil sample, and use the analytical value or set of analytical values, and the density of the oil sample to obtain a plurality of assigned assay values (for example a value and/or property representative of an elemental composition value, a physical property or an indicative property) to produce a virtual assay of the oil sample.

In one embodiment, an assigned assay value is calculated used a third degree multi variable polynomial equation including the analytical value, the density of the oil sample, and a plurality of constants, for example predetermined by linear regression, as denoted in equation (2a).

$\begin{array}{cc}\begin{array}{l}\text{AD}={\text{K}}_{\text{AD}}{\text{+X1}}_{\text{AD}}\ast {\text{AV+X2}}_{\text{AD}}\ast {\text{AV}}^{\text{2}}{\text{+X3}}_{\text{AD}}\ast {\text{AV}}^{\text{3}}{\text{+X4}}_{\text{AD}}\ast \text{ρ}\ast \\ \text{AV}\end{array}& \text{­­­(2a)}\end{array}$

where:

• AD is the assigned assay value (for example a value and/or property representative of an elemental composition value, a physical property or an indicative property);
• AV is an analytical value of the oil sample;
• p is the density of the oil sample, in certain embodiments a 15° C./4° C. density in units of kilograms per liter using the method described in ASTM D4052; and
• K_AD, X1_AD, X2_AD, X3_AD, and X4_AD are constants, for instance, developed using linear regression techniques (note that in certain embodiments and for certain assigned assay values, one or more of K_AD, X1_AD, X2_AD, X3_AD and X4_AD is/are not used, or is/are zero).

In another embodiment, an assigned assay value is calculated used a third degree multi variable polynomial equation including the analytical value, the density of the oil sample, and a plurality of constants, for example predetermined by linear regression, as denoted in equation (2b).

$\begin{array}{cc}\begin{array}{l}\text{AD}={\text{K}}_{\text{AD}}{\text{+X1}}_{\text{AD}}\ast \text{ρ}\text{+}{\text{X2}}_{\text{AD}}\ast {\text{ρ}}^{\text{2}}{\text{+X3}}_{\text{AD}}\ast {\text{ρ}}^{\text{3}}{\text{+X4}}_{\text{AD}}\ast \text{AV}+\\ {\text{X5}}_{\text{AD}}\ast {\text{AV}}^{\text{2}}\text{+}{\text{X6}}_{\text{AD}}\ast {\text{AV}}^{\text{3}}{\text{+X7}}_{\text{AD}}\ast \text{ρ}\ast \text{AV}\end{array}& \text{­­­(2b)}\end{array}$

where:

• AD is the assigned assay value (for example a value and/or property representative of an elemental composition value, a physical property or an indicative property);
• AV is an analytical value of the oil sample;
• ρ is the density of the oil sample, in certain embodiments a 15° C./4° C. density in units of kilograms per liter using the method described in ASTM D4052; and
• K_AD, X1_AD, X2_AD, X3_AD, X4_AD, X5_AD, X6_AD and X7_AD are constants, for instance, developed using linear regression techniques (note that in certain embodiments and for certain assigned assay values, one or more of K_AD, X1_AD, X2_AD, X3_AD, X4_AD, X5_AD, X6_AD and X7_AD is/are not used, or is/are zero).

Assigned assay values that can be determined and included for display or presentation to the user in the virtual assay produced using the systems and methods herein include one or more of:

• elemental composition of the oil sample and its fractions including the sulfur and nitrogen compositions;
• TAN (total acid number) of the oil sample;
• composition of certain desirable and undesirable compounds or types of compounds present in the oil sample and/or its fractions, including one or more of, micro carbon residue, C5-asphaltenes (the yield of asphaltenes using separation based on C5 paraffins as deasphalting solvent), paraffins, aromatics, and naphthenes;
• physical properties of the oil sample and/or its fractions including viscosity such as kinematic viscosity;
• indicative properties of the oil sample and/or its fractions, including one or more of cloud point, pour point, research octane number, cetane number and aniline point.

In certain embodiments, the assigned assay values can include yields of fractions from the oil sample, for example as mass fractions of boiling point ranges, including one or more of naphtha, gas oil, vacuum gas oil and vacuum residue. In certain embodiments, the assigned assay values can include composition information of hydrogen sulfide and/or mercaptans in the oil sample and/or its fractions. In certain embodiments, the assigned assay values can include elemental compositions of one or more of carbon, hydrogen, nickel, and vanadium. In certain embodiments, the assigned assay values can include physical properties of the oil sample and/or its fractions including one or more of API gravity and refractive index. In certain embodiments, the assigned assay values can include indicative properties of the oil sample and/or its fractions including one or more of flash point, freezing point and smoke point.

In certain embodiments, a method for producing a virtual assay of an uncharacterized oil sample is provided. The uncharacterized oil sample is characterized by a density, selected from the group consisting of crude oil, bitumen and shale oil, and characterized by naphtha, gas oil, vacuum gas oil and vacuum residue fractions. The virtual assay comprises a plurality of assigned data values. The uncharacterized oil sample is obtained, for instance the sample being between one to two milliliters in volume and not subject to any fractionation. A plurality of known data values (corresponding to the assigned data values used in the virtual assay) for known oil samples with known densities (which known oil samples exclude the uncharacterized oil sample) are obtained. This data is obtained from empirical data of a plurality of existing crude oil assays and/or analyses using conventional techniques including distillation and industry-established testing methods. One or more selected analytical techniques are carried out on the each of the known oil samples, and one or more analytical values are calculated for each of the known oil samples. The one or more selected analytical techniques are carried out on the uncharacterized oil sample, and one or more analytical values are calculated for the uncharacterized oil sample. Constants of a polynomial equation are obtained, and the polynomial equation is used to determine a plurality of assigned data values that make up the virtual assay of the uncharacterized oil sample. The polynomial equation is a function of density and the one or more analytical values of the uncharacterized oil sample. The constants of the polynomial equation are determined using a fitting method to fit the plurality of known data values of the plurality of known oil samples to the plurality of values of the density of the plurality of known oil samples and the plurality of the one or more analytical values for the plurality of known oil samples.

Rather than relying on conventional techniques including distillation and laborious, costly and time-consuming analytical methods to measure/identify data regarding the crude oil and/or its fractions including elemental composition, physical properties and indicative properties, as little as 1 gram of oil can be analyzed. From the analysis of a relatively small quantity of the oil sample, the assigned assay values are determined by direct calculation, without requiring distillation/fractionization.

A laser induced fluorescence spectroscopy system is the analytic characterization system that is employed on a relatively small quality of an oil sample, such as crude oil. An analytical value, comprising or consisting of the LIF index, from said analytic characterization technique, is used to calculate and assign physical and indicative properties that are the requisite data for the virtual oil sample assay. The method and system provides insight into the properties of oil sample, the naphtha fraction, the gas oil fraction, the vacuum gas oil fraction, and the vacuum residue fraction, without fractionation/distillation (conventional crude oil assays). The virtual oil sample assay will help producers, refiners, and marketers benchmark the oil quality and, as a result, evaluate (qualitatively and economically) 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, the method and system herein can provide a virtual assay in less than one day and in certain embodiments less than 1-2 hours. In addition, the method and system herein carried out at 1% or less of the cost of a traditional assay requiring distillation/fractionization follows by individual testing for each type of property and for each fraction.

The systems and methods herein are implemented using an index derived from LIF spectroscopy data as an analytical value in equations (1), and (2a) or (2b), above. Embodiments of such methods are described in the context of assigning an indicative property to a fraction of an oil sample in commonly owned US 10527546B 1, which is incorporated by reference herein in its entirety. In the systems and methods herein, and with reference to FIG. 1, a virtual assay 195 of an oil sample is obtained at step 190, wherein each assigned data value of the virtual assay is a function of the LIF index derived from LIF spectroscopy data based on the spectrometric analysis of the oil sample (or in another embodiment, as a function of the density of the oil sample and LIFI of the oil sample). The virtual assay provides information about the oil sample and fractions thereof to help producers, refiners, and marketers benchmark the oil quality and, as a result, evaluate the oils without performing the customary extensive and time-consuming crude oil assays involving fractionation/ distillation and several individual and discrete tests.

The oil sample is optionally prepared, step 115, by dissolving the oil sample in a suitable LIF solvent known for use in LIF spectroscopy. For example, in certain embodiments, a solution is prepared by dissolving the oil sample in a suitable solvent such as a paraffinic solvent for which LIF spectroscopy data is known, and thus can be subtracted from the LIF spectrum to yield accurate LIF spectroscopy data pertaining to the oil sample. In certain embodiments, the oil sample is directly analyzed in the absence of a solvent and without distillation, so that step 115 is avoided (and accordingly step 115 is shown in dashed lines in FIG. 1).

The oil sample or solution thereof is analyzed, step 120, and LIFS spectroscopy data is obtained. Step 120 is carried out and the analytic characterization data, the LIF spectroscopy data, is entered into the computer system 400 described herein with respect to FIG. 4, for example stored into non-volatile memory of the via data storage memory 480, represented as the analytic characterization data 125. This can be carried out by a raw data receiving module stored in the program storage memory 470.

An analytical value is obtained, step 130, as a function of fluorescence of the oil sample over a range of wavelengths. In certain embodiments the analytical value obtained from the LIF spectroscopy data includes an index of the oil sample described herein, for instance obtained as a function of a summation of fluorescence values over a range of wavelengths, the LIF index. Step 130 is carried out, for example, by execution by the processor 420 of one or more modules stored in the program storage memory 470, and the analytical values 135, the index, is stored in the program storage memory 470 or the data storage memory 480, for use in the modules determining the assigned data values. In certain embodiments, the density of the oil sample, provided at step 110, is stored in the program storage memory 470 or the data storage memory 480, for use in the modules determining the assigned data values; this can be carried out by a raw data receiving module stored in the program storage memory 470.

The assigned data values including virtual assay data 145 pertaining to the total oil sample, virtual assay data 155 pertaining to a naphtha fraction, virtual assay data 165 pertaining to a gas oil fraction, virtual assay data 175 pertaining to a vacuum gas oil fraction and virtual assay data 185 pertaining to a vacuum residue fraction, are obtained according to the functions described herein, for example, in the corresponding steps 140, 150, 160, 170 and 180. The constants used for determining the assigned data values, are provided at step 105 and are stored in the program storage memory 470 or the data storage memory 480, for use in the modules determining the assigned data values. The steps for obtaining the assigned data values are carried out, for example, by execution by the processor 420 of one or more modules stored in the program storage memory 470, and the several assigned data values are calculated and stored in the data storage memory 480, presented on the display 410 and/or presented to the user by some other output device such as a printer.

Laser-induced fluorescence spectroscopy (LIF) is a spectroscopic method where a sample is photochemically excited using a pulsed or continuous laser radiation source to produce time and wavelength resolved fluorescence spectra of the sample. In various embodiments, the radiation source may be an ultraviolet radiation source. In various embodiments, laser-induced fluorescence spectroscopy may be used to determine the concentration of hydrocarbon species and/ or non-hydrocarbon contaminants for evaluating the properties of a crude oil sample. In various embodiments, laser induced fluorescence spectroscopy may be used to generate two-dimensional and/or three-dimensional images of a crude oil sample.

For example, a laser induced ultraviolet (UV) fluorescence spectroscopy system can be used in accordance with various embodiments. A laser is provided to emit a laser light, a first mirror directs the laser light from the first mirror to provide a first reflected light to a second mirror. The second mirror reflects the first reflected light to provide a second reflected light to a cuvette with the oil sample under investigation therein. The oil sample in cuvette emits fluorescent light that is directed towards a lens system, which provides a focused fluorescent light to a spectrograph. The spectrograph is coupled to an intensified charge-coupled device (ICCD) that is coupled the computer system 400 to record UV fluorescence spectrographic data from the oil sample in the cuvette. The system laser induced UV fluorescence spectroscopy also typically includes a beam dump to receive reflected light. The cuvette typically includes four rectangular windows or sides and can be a standard UV quartz cuvette. The cuvette is typically sized to receive a small sample of crude oil, for instance approximately 1-2 milliliters. The first mirror, second mirror and cuvette are typically configured to provide a second reflected light beam at approximately a 45 degree angle to a side of the cuvette. The laser typically provides laser light as a Q-switched UV laser beam, for instance at a wavelength of approximately 266 nm at beam diameter of approximately 0.5 mm. The Q-switching in the laser produces energetic pulses, for example of approximately 35 millijoules per pulse for a period of 6 nanoseconds for each pulse. Other wavelengths of laser light can be used to induce a fluorescence response from the oil sample in the cuvette. Laser light can have higher or lower energetic pulses and can have longer or shorter pulses. The lens system can include two or more quartz lenses aligned to focus the fluorescent emission onto an entrance slit of a spectrograph. The ICCD can be a fast-gated ICCD and that produces emission spectra of the resulting fluorescence intensity as function of wavelength. The resulting fluorescence spectra can have a suitable resolution, for instance of approximately 1.5 nm. The spectra can be reconstructed using simulation software, for instance in a raw data receiving module 471 of the program storage memory 470.

The determination of the assigned data is carried out using variables comprising or consisting of the laser induced fluorescence index (LIFI) of the oil sample and the density of the oil sample.

$\begin{array}{cc}\text{AD}\text{=}\text{f}\left(\left(\text{ρ},\text{LIFI}\right)\right)& \text{­­­(3)}\end{array}$

where:

• AD is the assigned data value (for example a value and/or property representative of an elemental composition value, a physical property or an indicative property);
• LIFI = index derived from a summation of fluorescence intensities over a predetermined range of wavelengths, as determined by LIF spectroscopy of the oil sample; and
• ρ is the density of the oil sample, in certain embodiments a 15° C./4° C. density in units of kilograms per liter using the method described in ASTM D4052.

For example, this relationship can be expressed as follows:

$\begin{array}{cc}\begin{array}{l}\text{AD}={\text{K}}_{\text{AD}}{\text{+X1}}_{\text{AD}}\ast \text{ρ}\text{+}{\text{X2}}_{\text{AD}}\ast {\text{ρ}}^{\text{2}}{\text{+X3}}_{\text{AD}}\ast {\text{ρ}}^{\text{3}}{\text{+X4}}_{\text{AD}}\ast \text{LIFI}+\\ {\text{X5}}_{\text{AD}}\ast {\text{LIFI}}^{\text{2}}\text{+}{\text{X6}}_{\text{AD}}\ast {\text{LIFI}}^{\text{3}}{\text{+X7}}_{\text{AD}}\ast \text{ρ}\ast \text{LIFI}\end{array}& \text{­­­(4)}\end{array}$

where AD, LIFI and ρ are as in equation (3), and where:

K_AD, X1 _AD, X2_AD, X3_AD, X4_AD, X5_AD, X6_AD and X7 _AD are constants, for instance, developed using linear regression techniques, for each AD to be determined (note that in certain embodiments and for certain assigned assay values, one or more of K_AD, X1_AD, X2_AD, X3_AD, X4_AD, X5_AD, X6_AD and X7_AD is/are not used, or is/are zero).

Using the equation (4), one or more assigned data values AD are determined using the density of the oil sample and the LIFI of the oil sample, as determined by LIF spectroscopy of the oil sample.

Table 3 lists assigned data for a virtual assay of an oil sample under investigation, with descriptions, abbreviations and units, for each assigned data property for the naphtha fraction, the gas oil fraction, the vacuum gas oil fraction, the vacuum residue fraction and the overall oil sample. Table 3 further provides exemplary constants, for instance, developed using linear regression techniques, for plural assigned data values to be determined based on the density of the oil sample and the LIFI of the oil sample. These constants are used in the example below with the calculated values provided in Table 5 compared to the actual values as determined by a conventional crude oil assay.

The constants, for example as in Table 3, are stored as in step 105 in the process flow diagram of FIG. 1. These are used in one or more calculation modules to obtain the virtual assay 195 of an oil sample as in step 190, in conjunction with the analytical values obtained step 130 based upon LIF spectroscopy data, the LIFI of the oil sample. In certain embodiments the constants are stored as in step 105, and the density is stored as in step 110; the constants are used in one or more calculation modules to obtain the virtual assay 195 of an oil sample as in step 190, in conjunction with density of the oil sample stored in step 110 and the analytical values obtained in step 130 from the LIF spectroscopy data obtained in step 120, the LIFI of the oil sample. As shown, modules are separated based on the fraction for which assigned data values are obtained, but is it understood that they can be arranged in any manner so as to provide all of the assigned data values required for the virtual assay of the oil sample.

In certain embodiments, the assigned data values including virtual assay data 145 pertaining to the total oil sample, virtual assay data 155 pertaining to a naphtha fraction, virtual assay data 165 pertaining to a gas oil fraction, virtual assay data 175 pertaining to a vacuum gas oil fraction and virtual assay data 185 pertaining to a vacuum residue fraction. This data is obtained according to the function (3) described above (for example expressed as in equation (4) described above, for example, with the corresponding modules/steps 140, 150, 160, 170 and 180).

In certain embodiments, the analytical value obtained as in step 130 is a LIFI of the oil sample determined as follows:

$\begin{array}{cc}\text{LIFI}={\displaystyle \sum _{\omega =\omega 1}^{\omega 2}\frac{F{I}_{\omega }}{{10}^6}}& \text{­­­(5)}\end{array}$

where:

• ω is the wavelength of light;
• FI_ω is the fluorescence intensity of the oil sample for peaks detected at wavelengths over the range from ω₁ to ω₂, in arbitrary units;
• ω₁ is a beginning wavelength of light; and
• ω₂ is an ending wavelength of light;
• wherein the beginning and ending wavelength of light may be selected to be at FI values greater than background noise of FI.

The LIFI may be calculated by integrating the area under the plot of FI versus a wavelength of light detected by the detector of the UV detector of the laser induced UV fluorescence spectrometer. In various embodiments, the scatter spectra may be obtained using a spectroscopy method selected from the group consisting of absorption spectroscopy, Raman spectroscopy, resonance Raman spectroscopy, transmission spectroscopy, UV reflectance spectroscopy, and combinations thereof.

In various embodiments, fluorescence intensity may be measured in relative fluorescence units (RFU). In various embodiments, RFU may be measured as the fluorescence intensity values of a crude oil sample for peaks detected starting at ω equal to ω1 and up to ω equal to ω2. In various embodiments, ω1 can be approximately 283 nanometers, and ω2 can be approximately 600 nm. In various embodiments, LIFI may be calculated as the area under the curve for a plot of a measure of the fluorescence intensity, such as RFU for example, versus the wavelength of light detected by a detector. The area under the curve may be calculated according to equation (5) or may be calculated using any suitable method to estimate the area under the curve. The starting wavelength ω1 and the ending wavelength ω2 may be optimized to provide improved accuracy in the calculation of LIFI for purposes of estimating properties of a hydrocarbon fraction or crude oil. For example, ω1 can be from about 270 nm or lower to about 300 nm or higher. Similarly, ω2 can be from about 550 nm or lower to about 620 nm or higher. In various embodiments, ω may be incremented by 1 nm in equation (5). In various embodiments, ω may be incremented by 1.5 nm in equation (5). Any reasonable measure of the area under the curve may be used to calculate/estimate a value of LIFI, within reasonable engineering tolerances. In various embodiments, the value of LIFI may be a normalized value, where the normalized value may be with respect to a standard sample. Normalization allows for comparison of index values from different fluorescence spectrometers. In various embodiments, a normalized LIFI can be used where LIFI is designated.

EXAMPLE

Crude oil samples, including a crude oil sample as the oil sample under investigation, were analyzed by LIF spectroscopy according to the methods described herein. FIG. 2 shows a graphic plot of typical LIF spectroscopy data for nine types of crude oil as oil samples, where the fluorescence intensity (in arbitrary units, a.u.) is plotted against wavelength in nanometers. The spectral data for two samples with API gravities of 28.8° and 27.4° are presented in Table 4. FIG. 3 shows a process flow chart of steps for a method of obtaining assigned data based on LIF data. In step 305, constants are obtained, for example corresponding to the data in Table 3. In step 310, the density of the oil sample is obtained. In the Example, the oil sample is Arabian medium crude with a 15° C./4° C. density of 0.8828 Kg/L, determined using the method described in ASTM D4052.

At step 320, analytic characterization of the oil sample, without fractionation, is carried out. A sample of Arabian medium crude with a density of 0.8828 Kg/l was analyzed by LIF spectroscopy. The spectral data is presented in Table 4 for samples with an API gravities of 28.8° and 27.4° and spectral data is shown in FIG. 2. The data pertaining to the spectrum is obtained and stored as the analytic characterization data in step 325.

In this example, 2 ml oil samples of selected crude oil samples were transferred (directly and without distillation) to a standard UV quartz cuvette with four (4) rectangular windows or sides. The cuvette and the aliquot was inserted into the spectrometer cell holder at an angle such that the incident laser beam was focused onto one of the four cuvette windows at a fixed angle of approximately 45 degrees for the duration of the experiment. A Q-switched UV laser beam at an initially fixed wavelength of 266 nanometers (nm) and a fixed beam diameter of about 0.5 mm was used to excite the crude oil aliquot within the cuvette. The Q-switching in the laser produced energetic pulses of about 35 millijoules (mJ) per pulse with a temporal span of about 6 nanoseconds (ns) for each pulse. The resulting fluorescence of for each of the crude oil samples was collected using a combination of quartz lenses aligned for focusing the resulting emission onto the entrance slit of an operably connected spectrograph. The spectrograph was coupled with a fast-gated intensified charge-coupled device (ICCD) to produce emission spectra of the resulting fluorescence intensity as function of wavelength. The spectral resolution was about 1.5 nm, and the spectra were reconstructed using simulation software. The ICCD was initiated by the Q-switching of the laser pulse, and the detection of the resulting fluorescence signal was limited to the first six nanoseconds as measured from the start from the maximal value of the laser pulse intensity. FIG. 2 illustrates the fluorescence spectra for nine different crude oils with differing API gravity values.

At step 330, an analytical value, the laser induced fluorescence spectroscopy index (LIFI), is calculated as a function of the summation the intensities of the detected peaks over the selected range of wavelengths, as in equation (5) herein, with the value in the example using the data in Table 4 for the sample with an API gravity of 28.8° is calculated as 3.1546555 over the wavelength range of 283 to 600 nm.

The LIFI, stored at step 335, is applied to step 390. At step 390, equation (4) and the constants from Table 3 are applied for each of the listed Ads, using the LIFI stored at step 335, the constants stored at step 305, and the density of the oil sample stored at step 310, as shown below. Each of the determined Ads can be added to a virtual assay of the oil sample 395. For example, this can be carried out as one step, or as plural steps, for instance, similar to steps 140, 150, 160, 170 and 180 described herein in conjunction with FIG. 1 to calculate a plurality of different elemental composition values / physical properties/ indicative properties that make up the virtual assay, for each of a total oil sample, a naphtha fraction, a gas oil fraction, a vacuum gas oil fraction and a vacuum residue fraction, respectively, and to produce the virtual oil sample assay 195 at step 190.

Equation (4) is applied to each of the Ads that make up the virtual assay including those identified in Table 3, using the corresponding units. In addition, the constants denoted in Table 3 are used as the constants K_AD, X1_AD, X2_AD, X3_AD, X4_AD, X5_AD, X6_AD and X7_AD) in equation (4); the LIFI based on the data in Table 4, calculated as 2.3377 using equation (5) above, is used in equation (4); and the density ρ used in equation (4) for the of the oil sample under investigation is the 15° C./4° C. density in units of kilograms per liter using the method described in ASTM D4052, which is 0.8828 Kg/L. The calculated AD values are provided for the oil sample under investigation in Table 5, compared to the actual values obtained using a conventional crude oil assay.

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, pointer, motion sensor, microphone and/or camera 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.

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 stores one or more of: a raw data receiving module 471, having one or more software programs adapted to receive the analytic characterization data 125, for instance obtained at step 120 in the process flow diagram of FIG. 1; an analytical value calculation module 472, having one or more software programs adapted to determine one or more analytical values 135 based on the type of analytic characterization data 125 received by module 471, for instance calculated at step 130 in the process flow diagram of FIG. 1 using equation (5) herein based on the LIF data; one or more assigned assay value calculation modules 473, having one or more software programs adapted to determine a plurality of assigned assay values to produce a virtual assay 195 of an oil sample, for instance using the one or more analytical values 135 calculated by module 472 and the set of constants 105 (and in certain embodiments the density 110), for instance as in step 190 in the process flow diagram of FIG. 1 (in certain embodiments using steps 140, 150, 160, 170 and 180 to calculate and assign a plurality of different elemental composition values / physical properties/ indicative properties that make up the virtual assay, for each of a total oil sample, a naphtha fraction, a gas oil fraction, a vacuum gas oil fraction and a vacuum residue fraction, respectively, to produce corresponding assigned assay values for the virtual assay 195, include including assigned assay values 145 pertaining to the total oil sample, assigned assay values 155 pertaining to a naphtha fraction, assigned assay values 165 pertaining to a gas oil fraction, assigned assay values 175 pertaining to a vacuum gas oil fraction and assigned assay values 185 pertaining to a vacuum residue fraction); and optionally a density receiving module 474 (in embodiments in which density is used to determine assigned assay values for the virtual assay), shown in dashed lines, having one or more software programs adapted to receive the density data 110, which in certain embodiments can be integrated in the raw data receiving module 471 or the assigned assay value calculation modules 473 (shown by overlapping dashed lines). Data storage memory 480 stores results and other data generated by the one or more program modules of the present invention, including the constants 105, the density 110, the analytic characterization data 125, the one or more analytical values 135, and the assigned assay values (which can be a single set of assigned data values to produce the virtual assay 195, or alternatively delineated by type including the assigned assay values 145, 155, 165, 175 and 185 described herein).

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.

Computer system 400 generally 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.

Note that steps 110 and 120 can be carried out separate from or within the computer system 400. For example, step 110 can be carried out and the data entered into the computer system 400, for example via data storage memory 480, or as a single value incorporated in the program storage memory 470 for one or more of the modules. Step 120 can be carried out and the analytic characterization data entered into the computer system 400, for example via data storage memory 480, represented as the analytic characterization data 125.

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.

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. Pat. Application 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.

It is to be understood that like numerals in the drawings represent like elements through the several figures, and that not all components and/or steps described and illustrated with reference to the figures are required for all embodiments or arrangements. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms ““including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should be noted that use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

Notably, the figures and examples above are not meant to limit the scope of the present disclosure to a single implementation, as other implementations are possible by way of interchange of some or all the described or illustrated elements. Moreover, where certain elements of the present disclosure can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present disclosure are described, and detailed descriptions of other portions of such known components are omitted so as not to obscure the disclosure. In the present specification, an implementation showing a singular component should not necessarily be limited to other implementations including a plurality of the same component, and vice-versa, unless explicitly stated otherwise herein. Moreover, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present disclosure encompasses present and future known equivalents to the known components referred to herein by way of illustration.

The foregoing description of the specific implementations will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the relevant art(s), readily modify and/or adapt for various applications such specific implementations, without undue experimentation, without departing from the general concept of the present disclosure. Such adaptations and modifications are therefore intended to be within the meaning and range of equivalents of the disclosed implementations, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance presented herein, in combination with the knowledge of one skilled in the relevant art(s). It is to be understood that dimensions discussed or shown are drawings are shown accordingly to one example and other dimensions can be used without departing from the disclosure.

The subject matter described above is provided by way of illustration only and should not be construed as limiting. Various modifications and changes can be made to the subject matter described herein without following the example embodiments and applications illustrated and described, and without departing from the true spirit and scope of the invention encompassed by the present disclosure, which is defined by the set of recitations in the following claims and by structures and functions or steps which are equivalent to these recitations.

Fraction             Boiling Point, °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+

Property	Unit	Property Type	Fraction
Yield	W% or V%	Yield	All
API Gravity	°	Physical	All
Viscosity Kinematic @ 38° C.	°	Physical	Fraction boiling >250° C.
Refractive Index @ 20° C.	Unitless	Physical	Fraction boiling <400° C.
Sulfur	W% or ppmw	Composition	All
Mercaptan Sulfur, W%	W%	Composition	Fraction boiling <250° C.
Nickel	ppmw	Composition	Fraction boiling >400° C.
Vanadium	ppmw	Composition	Fraction boiling >400° C.
Nitrogen	ppmw	Composition	All
Flash Point	°C	Indicative	All
Cloud Point	°C	Indicative	Fraction boiling >250° C.
Pour Point	°C	Indicative	Fraction boiling >250° C.
Freezing Point	°C	Indicative	Fraction boiling >250° C.
Micro Carbon Residue	W%	Indicative	Fraction boiling >300° C.
Smoke Point, mm	mm	Indicative	Fraction boiling between 150-250° C.
Octane Number	Unitless	Indicative	Fraction boiling <250° C.
Cetane Index	Unitless	Indicative	Fraction boiling between 150-400° C.
Aniline Point	°C	Indicative	Fraction boiling <520° C.

Fraction	property	Units	KAD	X1AD
Naphtha	Aromatics (Aro)	W%	3.175581E+06	-1.103943E+07
Hydrogen (H)	W%	-7.661080E+04	2.808439E+05
Paraffins (P)	W%	1.433357E+07	-4.943232E+07
Sulfur (S)	ppmw	-4.954253E+04	0.000000E+00
Octane Number (ON)	Unitless	-1.865020E+07	6.485548E+07
Gas Oil (GO)	Aniline Point (AP)	°C	7.550480E+06	-2.620191E+07
Cetane Number (CN)	Unitless	8.966141E+06	-3.074830E+07
Cloud Point (CP)	°C	1.975611E+06	-6.912474E+06
Nitrogen (N)	ppmw	-2.785507E+08	9.664774E+08
Sulfur (S)	ppmw	5.832730E+09	-2.007120E+10
Kinematic Viscosity @40° C.	cSt	-1.086111E+06	3.774550E+06
Pour Point (PP)	°C	1.593899E+07	-5.499806E+07
Vacuum Gas Oil (VGO)	Nitrogen (N)	ppmw	5.253686E+03	0.000000E+00
Sulfur (S)	ppmw	1.216410E+05	0.000000E+00
Vacuum Residue (VR)	Micro Carbon Resid (MCR)	W%	6.546900E+02	0.000000E+00
Sulfur (S)	ppmw	2.243576E+05	0.000000E+00
Oil Sample	C5-Asphaltenes (C5A)	W%	-5.854068E+05	1.999480E+06
Micro Carbon Resid (MCR)	W%	-2.013653E+05	6.187884E+05
Pour Point (PP)	°C	3.878972E+07	-1.350130E+08
Kinematic Viscosity @ 100° C.	cSt	-4.938961E+05	1.660735E+06
Kinematic Viscosity @70° C.	cSt	1.505415E+06	-5.397887E+06
Nitrogen (N)	ppmw	-5.293648E+08	1.812129E+09
Sulfur (S)	ppmw	2.687640E+10	-9.291390E+10
Total Acid Number (TAN)	mg KOH/100 g	-7.800404E+05	2.695494E+06
Aromatics (Aro)	W%	4.797608E+06	-1.692564E+07

Fraction	property	Units	X2AD	X3AD
Naphtha	Aromatics (Aro)	W%	1.279274E+07	-4.940677E+06
Hydrogen (H)	W%	-3.415079E+05	1.378005E+05
Paraffins (P)	W%	5.684729E+07	-2.179554E+07
Sulfur (S)	ppmw	0.000000E+00	6.382855E+04
Octane Number (ON)	Unitless	-7.518526E+07	2.904967E+07
Gas Oil (GO)	Aniline Point (AP)	°C	3.031491E+07	-1.169078E+07
Cetane Number (CN)	Unitless	3.516287E+07	-1.340729E+07
Cloud Point (CP)	°C	8.059573E+06	-3.130748E+06
Nitrogen (N)	ppmw	-1.118001E+09	4.310801E+08
Sulfur (S)	ppmw	2.303147E+10	-8.811446E+09
Kinematic Viscosity @40° C.	cSt	-4.373236E+06	1.688823E+06
Pour Point (PP)	°C	6.327654E+07	-2.427021E+07
Vacuum Gas Oil (VGO)	Nitrogen (N)	ppmw	0.000000E+00	-7.262024E+03
Sulfur (S)	ppmw	0.000000E+00	-1.270522E+05
Vacuum Residue (VR)	Micro Carbon Resid (MCR)	W%	0.000000E+00	-9.270145E+02
Sulfur (S)	ppmw	0.000000E+00	-2.498112E+05
Oil Sample	C5-Asphaltenes (C5A)	W%	-2.277383E+06	8.649292E+05
Micro Carbon Resid (MCR)	W%	-6.264753E+05	2.085422E+05
Pour Point (PP)	°C	1.566518E+08	-6.057532E+07
Kinematic Viscosity @ 100° C.	cSt	-1.861039E+06	6.952259E+05
Kinematic Viscosity @70° C.	cSt	6.441275E+06	-2.556840E+06
Nitrogen (N)	ppmw	-2.068650E+09	7.874092E+08
Sulfur (S)	ppmw	1.071026E+11	-4.115690E+10
Total Acid Number (TAN)	mg KOH/100 g	-3.105717E+06	1.192908E+06
Aromatics (Aro)	W%	1.988989E+07	-7.783592E+06

Fraction	property	Units	X4AD	X5AD
Naphtha	Aromatics (Aro)	W%	-5.401793E+02	6.495798E+01
Hydrogen (H)	W%	-3.411747E+01	-3.863655E+00
Paraffins (P)	W%	-4.181768E+03	2.652183E+02
Sulfur (S)	ppmw	0.000000E+00	1.090631E+03
Octane Number (ON)	Unitless	3.917344E+03	-4.465403E+02
Gas Oil (GO)	Aniline Point (AP)	°C	-1.727532E+03	1.703291E+02
Cetane Number (CN)	Unitless	-2.757531E+03	1.100931E+02
Cloud Point (CP)	°C	-1.750613E+02	4.733558E+01
Nitrogen (N)	ppmw	6.521941E+04	-6.316806E+03
Sulfur (S)	ppmw	-1.738238E+06	9.179812E+04
Kinematic Viscosity @40° C.	cSt	2.457996E+02	-2.637005E+01
Pour Point (PP)	°C	-4.185447E+03	2.746676E+02
Vacuum Gas Oil (VGO)	Nitrogen (N)	ppmw	0.000000E+00	-2.257561E+02
Sulfur (S)	ppmw	0.000000E+00	-2.854332E+03
Vacuum Residue (VR)	Micro Carbon Resid (MCR)	W%	0.000000E+00	-1.771407E+01
Sulfur (S)	ppmw	0.000000E+00	-5.402345E+03
Oil Sample	C5-Asphaltenes (C5A)	W%	2.043902E+02	-5.444595E+00
Micro Carbon Resid (MCR)	W%	2.576833E+02	1.216791E+01
Pour Point (PP)	°C	-7.475127E+03	9.354596E+02
Kinematic Viscosity @ 100° C.	cSt	1.268046E+02	1.174814E+01
Kinematic Viscosity @70° C.	cSt	-1.639007E+02	9.531827E+01
Nitrogen (N)	ppmw	1.789610E+05	-6.294318E+03
Sulfur (S)	ppmw	-7.121095E+06	5.315193E+05
Total Acid Number (TAN)	mg KOH/100 g	2.010068E+02	-1.466006E+01
Aromatics (Aro)	W%	-1.532301E+02	1.456335E+02

Fraction	property	Units	X6AD	X7AD
Naphtha	Aromatics (Aro)	W%	-3.280907E+00	1.924907E+02
Hydrogen (H)	W%	1.942297E-01	6.441187E+01
Paraffins (P)	W%	-1.341901E+01	3.046711E+03
Sulfur (S)	ppmw	-8.776323E+01	-5.723177E+02
Octane Number (ON)	Unitless	2.254971E+01	-1.553955E+03
Gas Oil (GO)	Aniline Point (AP)	°C	-8.598005E+00	8.580581E+02
Cetane Number (CN)	Unitless	-5.632973E+00	2.444498E+03
Cloud Point (CP)	°C	-2.403354E+00	-1.072478E+02
Nitrogen (N)	ppmw	3.192569E+02	-3.325650E+04
Sulfur (S)	ppmw	-4.652660E+03	1.387946E+06
Kinematic Viscosity @40° C.	cSt	1.329379E+00	-1.077879E+02
Pour Point (PP)	°C	-1.396151E+01	3.004273E+03
Vacuum Gas Oil (VGO)	Nitrogen (N)	ppmw	1.537933E+01	7.624723E+02
Sulfur (S)	ppmw	1.871421E+02	6.140650E+03
Vacuum Residue (VR)	Micro Carbon Resid (MCR)	W%	1.232810E+00	4.778862E+01
Sulfur (S)	ppmw	3.355659E+02	1.559835E+04
Oil Sample	C5-Asphaltenes (C5A)	W%	2.812177E-01	-1.993870E+02
Micro Carbon Resid (MCR)	W%	-6.007885E-01	-3.776837E+02
Pour Point (PP)	°C	-4.733663E+01	2.441169E+03
Kinematic Viscosity @ 100° C.	cSt	-5.808959E-01	-2.250343E+02
Kinematic Viscosity @70° C.	cSt	-4.781042E+00	-4.444670E+02
Nitrogen (N)	ppmw	3.200145E+02	-1.638580E+05
Sulfur (S)	ppmw	-2.687244E+04	4.663366E+06
Total Acid Number (TAN)	mg KOH/100 g	7.437418E-01	-1.344664E+02
Aromatics (Aro)	W%	-7.334911E+00	-7.824062E+02

Wavelength, nm	Crude 1 API = 28.8°	Crude 2 API = 27.4°
283	2533	2229
284	1925	2293
285	1589	2374
286	2071	1399
287	2172	2207
288	1700	1404
289	1723	1964
290	2313	2239
291	2827	2377
292	2569	2453
293	2349	2642
294	2045	2846
295	2217	2606
296	2518	2329
297	2562	2931
298	3192	2671
299	2266	3072
300	2793	3150
301	3258	2870
302	3380	3608
303	3392	2926
304	4057	3869
305	3807	4037
306	4922	3491
307	4492	4142
308	4756	4854
309	5290	5550
310	6172	5533
311	6671	5810
312	6638	7132
313	7615	7116
314	8154	8055
315	9478	8862
316	10520	9888

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
317	10673	9935
318	12667	11124
319	12579	11623
320	13206	11909
321	13331	12847
322	15063	13990
323	14660	13843
324	16503	15107
325	16612	15758
326	17752	15864
327	18029	17237
328	19963	17993
329	18942	18623
330	21263	19318
331	22016	20085
332	23030	21060
333	24344	22203
334	24779	23990
335	27869	24203
336	28979	26844
337	30710	27792
338	32430	29174
339	35163	30955
340	35982	32703
341	38680	34904
342	41088	36602
343	42805	37940
344	45447	40355
345	46722	41923
346	48941	43950
347	51126	45384
348	52734	47401
349	55647	49629
350	57209	51362
351	60369	53357
352	62615	56110
353	64481	57903
354	67626	60018

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
355	71322	63831
356	74627	64889
357	77316	69261
358	82988	71863
359	86388	75262
360	90735	79052
361	94513	82015
362	99231	85314
363	103493	89486
364	107102	92245
365	111570	95020
366	115048	99540
367	118831	101792
368	121824	104330
369	126031	108308
370	128402	111153
371	131452	111854
372	134887	114664
373	136688	117067
374	139274	118927
375	143124	120944
376	145021	124053
377	148676	126957
378	150409	128167
379	154040	129882
380	153204	129377
381	158102	132376
382	160146	133499
383	161628	135191
384	162740	136106
385	164329	136516
386	166967	138932
387	167600	138682
388	168629	139413
389	170547	141818
390	171784	141954
391	171637	143307
392	171576	142213

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
393	173682	144258
394	174962	144150
395	176004	144783
396	176402	144994
397	176891	146836
398	177328	145306
399	179500	147283
400	177733	146605
401	178407	147255
402	179569	146905
403	179412	147258
404	178569	145785
405	179102	145864
406	180090	146780
407	179504	146764
408	180137	147206
409	180548	147712
410	180279	145875
411	178189	146376
412	178355	145693
413	177908	144959
414	177920	145348
415	176467	143386
416	175247	142439
417	174055	141745
418	173060	140886
419	172054	140424
420	170763	139331
421	170813	139233
422	170648	137928
423	169624	137084
424	168176	136467
425	166949	136398
426	166644	133006
427	163869	133064
428	164317	131752
429	162025	130243
430	160674	129345

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
431	157933	128243
432	156799	126119
433	155915	125234
434	154201	123712
435	153026	122139
436	150454	120476
437	149665	121200
438	147972	117146
439	145372	117156
440	144243	115651
441	142637	114614
442	140302	112923
443	139870	112657
444	136375	110729
445	134417	109654
446	133623	108739
447	131655	106128
448	128464	105405
449	128869	103827
450	126147	103553
451	122958	100621
452	123258	100068
453	122061	99447
454	119715	97214
455	118282	96916
456	116159	95221
457	115287	93529
458	113518	92666
459	112716	90743
460	110533	90317
461	109059	88090
462	107834	87533
463	106323	85673
464	104581	85672
465	102713	85115
466	102190	82367
467	99801	81123
468	98581	78631

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
469	97790	78260
470	95193	77702
471	94465	76745
472	93551	74711
473	91720	73368
474	90512	72131
475	89185	71357
476	88422	70099
477	85896	69086
478	84775	66851
479	83740	66305
480	82836	64634
481	81911	64422
482	79912	63023
483	78857	62187
484	77448	61551
485	75629	60649
486	75164	59332
487	73504	58507
488	71739	57484
489	71147	56114
490	70135	56417
491	68244	54197
492	66558	53631
493	66237	53251
494	65402	51506
495	64211	51252
496	62971	50307
497	62805	50311
498	60166	48948
499	60326	47763
500	58902	48382
501	58449	47019
502	57264	46520
503	56987	45045
504	54966	44836
505	54825	43605
506	53606	44116

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
507	53185	43465
508	52441	43223
509	50591	42191
510	50117	41409
511	49697	41753
512	49568	39984
513	48271	40072
514	46594	40180
515	47069	38387
516	46439	38799
517	45933	38061
518	45563	37166
519	44639	37552
520	43795	35530
521	43469	36095
522	42155	34608
523	41549	35288
524	41433	34523
525	40956	34450
526	41154	33983
527	39253	32692
528	39572	32549
529	38589	32494
530	38053	31150
531	37399	30990
532	37307	30365
533	36276	29987
534	36206	29108
535	35205	29010
536	35671	27902
537	34531	27992
538	33872	27682
539	32661	26913
540	33070	27293
541	32009	25699
542	32410	26547
543	31867	24609
544	30827	25235

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
545	30570	24767
546	29468	24579
547	29676	23983
548	28726	22972
549	28551	23391
550	28687	22437
551	26184	22018
552	26578	21354
553	26361	22029
554	26010	21208
555	26264	21250
556	25533	20620
557	24608	19632
558	24447	20363
559	23731	19959
560	22711	19174
561	22869	19055
562	22580	18517
563	21943	18354
564	22050	17319
565	21764	18330
566	21086	17434
567	20523	17671
568	20268	17219
569	19934	16644
570	20014	16466
571	19262	15710
572	19275	16133
573	18918	16207
574	18488	15825
575	18063	14875
576	17565	15556
577	17886	14514
578	17075	14491
579	17398	14068
580	16880	14073
581	16684	13834
582	16181	13910

Wavelength, nm	Intensity Crude 1 (API = 28.8°)	Intensity Crude 2 (API = 27.4°)
583	16212	13654
584	15796	13218
585	15912	12442
586	14781	12830
587	15122	12453
588	14622	11690
589	14806	12087
590	14241	12307
591	14741	11893
592	13257	11473
593	13324	11736
594	13039	11404
595	12060	10984
596	13535	10448
597	11781	10699
598	13597	9861
599	11106	9258
600	12336	10198

AD Description	Unit	Conventional Crude Oil Assay Value	Calculated AD Value Equation (4)
Naphtha, Aro	W%	11.0	11.0
Naphtha, H	W%	14.7	14.7
Naphtha, P	W%	75.8	75.8
Naphtha, S	ppmw	876	876
Naphtha, ON	Unitless	52.5	52.5
GO, AP	°C	66.0	66.0
GO, CN	Unitless	59.5	59.5
GO, CP	°C	-10.0	-10.0
GO, N	ppmw	71.2	71.2
GO, S	ppmw	13,090	13,090
GO, Kinematic Viscosity @40° C.	cSt	2.9	2.9
GO, PP	°C	-9.0	-9.0
VGO, N	ppmw	617	617
VGO, S	ppmw	28,800	28,800
VR, MCR	W%	12.4	12.4
VR, S	ppmw	52,700	52,700
Oil Sample, C5A	W%	1.4	1.4
Oil Sample, MCR	W%	6.2	6.2
Oil Sample, PP	°C	-15.0	-15.0
Oil Sample, Kinematic Viscosity @ 100° C.	cSt	11.8	11.8
Oil Sample, Kinematic Viscosity @70° C.	cSt	21.7	21.7
Oil Sample, N	ppmw	829	829
Oil Sample, S	ppmw	30,000	30,000
Oil Sample, TAN	mg KOH/100 g	0.1	0.1
Oil Sample, Aro	W%	20.2	20.2

Claims

1. A method for producing a virtual assay of an oil sample, wherein the oil sample is characterized by a density, selected from the group consisting of crude oil, bitumen and shale oil, and characterized by naphtha, gas oil, vacuum gas oil and vacuum residue fractions, the method comprising: entering into a computer laser induced fluorescence (LIF) spectroscopy data indicative of fluorescence intensity over a predetermined range of wavelengths for a solution of the oil sample without distillation in a fluorescence spectroscopy solvent;calculating and assigning, as a function of the LIF spectroscopy data, an analytical value (AV); andcalculating and assigning, as a function of the AV and the density of the oil sample, virtual assay data of the oil sample and the naphtha, gas oil, vacuum gas oil and vacuum residue fractions, said virtual assay data comprising a plurality of assigned data values.

2. The method of claim 1, wherein virtual assay data comprises: a plurality of assigned assay data values pertaining to the oil sample including one or more of aromatic content, C5-asphaltenes content, elemental compositions of sulfur and nitrogen, micro-carbon residue content, total acid number and viscosity;a plurality of assigned assay values pertaining to the vacuum residue fraction of the oil sample including one or more of elemental composition of sulfur and micro-carbon residue content;a plurality of assigned assay values pertaining to the vacuum gas oil fraction of the oil sample including elemental compositions of one or more of sulfur and nitrogen;a plurality of assigned assay values pertaining to the gas oil fraction of the oil sample including one or more of elemental compositions of sulfur and nitrogen, viscosity, and indicative properties including aniline point, cetane number, cloud point and pour point; anda plurality of assigned assay values pertaining to the naphtha fraction of the oil sample including one or more of aromatic content, elemental composition of hydrogen and sulfur, paraffin content and octane number.

3. The method of claim 1, wherein virtual assay data comprises: a plurality of assigned assay data values pertaining to the oil sample including aromatic content, C5-asphaltenes content, elemental compositions of sulfur and nitrogen, micro-carbon residue content, total acid number and viscosity;a plurality of assigned assay values pertaining to the vacuum residue fraction of the oil sample including elemental composition of sulfur and micro-carbon residue content;a plurality of assigned assay values pertaining to the vacuum gas oil fraction of the oil sample including elemental compositions of sulfur and nitrogen;a plurality of assigned assay values pertaining to the gas oil fraction of the oil sample including elemental compositions of sulfur and nitrogen, viscosity, and indicative properties including aniline point, cetane number, cloud point and pour point; anda plurality of assigned assay values pertaining to the naphtha fraction of the oil sample including aromatic content, elemental composition of hydrogen and sulfur, paraffin content and octane number.

4. The method of claim 3, wherein virtual assay data further comprises: yields of fractions from the oil sample as mass fractions of boiling point ranges, including one or more of naphtha, gas oil, vacuum gas oil and vacuum residue;composition information of hydrogen sulfide and/or mercaptans in the oil sample and/or its fractions;elemental compositions of one or more of carbon, hydrogen, nickel, and vanadium;physical properties of the oil sample and/or its fractions including one or more of API gravity and refractive index; orindicative properties of the oil sample and/or its fractions including one or more of flash point, freezing point and smoke point.

5. The method of claim 1, further comprising operating a laser induced fluorescence spectroscopy system to obtain fluorescence intensities over the predetermined range of wavelengths as the LIF spectroscopy data, by carrying out spectroscopy on the oil sample directly and without distillation.

6. The method of claim 5, wherein a starting wavelength of the range is about is about 270-300 nm and an ending wavelength of the range is about 550-620 nm.

7. The method of claim 1,wherein each assay value is determined by a multi-variable polynomial equation with predetermined constant coefficients developed using linear regression techniques, wherein corresponding variables are the AV and the density of the oil sample.

8. The method of claim 7, wherein each assay value is determined by AD=KAD+X1AD*AV+X2AD*AV2+X3AD*AV3+X4AD*ρ*AVwhere:AD is the assigned assay value that is a value and/or property representative of an elemental composition value, a physical property or an indicative property;AV is the analytical value of the oil sample;ρ is the density of the oil sample; andKAD, X1AD, X2AD, X3AD, and X4AD are constants.

9. The method of claim 7, wherein each assay value is determined by AD=KAD+X1AD*ρ+X2AD*ρ2+X3AD*ρ3+X4AD*AV+X5AD*AV2+X6AD*AV3+X7AD*ρ*AVwhere:AD is the assigned assay value that is a value and/or property representative of an elemental composition value, a physical property or an indicative property;AV is the analytical value of the oil sample;ρ is the density of the oil sample; andKAD, X1AD, X2AD, X3AD, X4AD, X5AD, X6AD and X7AD are constants.

10. The method of claim 9, wherein the analytical value is a LIF spectroscopy index based upon a summation of fluorescence intensity over the range of wavelengths used in LIF spectroscopy of the oil sample.

11. The method of claim 9, wherein the analytical value is a LIF spectroscopy index (LIFI) obtained by a function: LIFI=∑w=w1w2FIw106where:ω is the wavelength of light,FIω is the fluorescence intensity of the oil sample for peaks detected at wavelengths over the range from ω1 to ω2, in arbitrary units,ω1 is a beginning wavelength of light, andω2 is an ending wavelength of light.

12. A system for producing a virtual assay of an oil sample, wherein the oil sample is characterized by a density, selected from the group consisting of crude oil, bitumen and shale oil, and characterized by naphtha, gas oil, vacuum gas oil and vacuum residue fractions, the system comprising: a laser induced fluorescence spectroscopy system that outputs laser induced fluorescence (LIF) spectroscopy data;a non-volatile memory device that stores calculation modules and data, the data including the LIF spectroscopy data, wherein the LIF spectroscopy data is indicative of fluorescence intensity over a predetermined range of wavelengths for the oil sample without distillation;a processor coupled to the non-volatile memory device;a first calculation module that is stored in the non-volatile memory device and that is executed by the processor, wherein the first calculation module calculates an analytical value (AV) as a function of the LIF spectroscopy data; anda second calculation module that is stored in the non-volatile memory device and that is executed by the processor, wherein the second calculation module calculates, as a function of the AV and the density of the oil sample, virtual assay data of the oil sample and the naphtha, gas oil, vacuum gas oil and vacuum residue fractions, said virtual assay data comprising a plurality of assigned data values.

13. The system as in claim 12, wherein virtual assay data comprises: a plurality of assigned assay data values pertaining to the oil sample including aromatic content, C5-asphaltenes content, elemental compositions of sulfur and nitrogen, micro-carbon residue content, total acid number and viscosity;a plurality of assigned assay values pertaining to the vacuum residue fraction of the oil sample including elemental composition of sulfur and micro-carbon residue content;a plurality of assigned assay values pertaining to the vacuum gas oil fraction of the oil sample including elemental compositions of sulfur and nitrogen;a plurality of assigned assay values pertaining to the gas oil fraction of the oil sample including elemental compositions of sulfur and nitrogen, viscosity, and indicative properties including aniline point, cetane number, cloud point and pour point;a plurality of assigned assay values pertaining to the naphtha fraction of the oil sample including aromatic content, elemental composition of hydrogen and sulfur, paraffin content and octane number.

14. The system as in claim 13, wherein virtual assay data further comprises: yields of fractions from the oil sample as mass fractions of boiling point ranges, including one or more of naphtha, gas oil, vacuum gas oil and vacuum residue;composition information of hydrogen sulfide and/or mercaptans in the oil sample and/or its fractions;elemental compositions of one or more of carbon, hydrogen, nickel, and vanadium;physical properties of the oil sample and/or its fractions including one or more of API gravity and refractive index; orindicative properties of the oil sample and/or its fractions including one or more of flash point, freezing point and smoke point.

15. The system of claim 12, wherein each assay value is calculated and assigned by the second calculation module with a multi-variable polynomial equation with predetermined constant coefficients developed using linear regression techniques, wherein corresponding variables are the AV and the density of the oil sample.

16. The system of claim 15, wherein each assay value is calculated and assigned by the second calculation module with a function: AD=KAD+X1AD*AV+X2AD*AV2+X3AD*AV3+X4AD*ρ*AVwhere:AD is the assigned assay value that is a value and/or property representative of an elemental composition value, a physical property or an indicative property;AV is the analytical value of the oil sample;ρ is the density of the oil sample; andKAD, X1AD, X2AD, X3AD, and X4AD are constants.

17. The system of claim 15, wherein each assay value is calculated and assigned by the second calculation module with a function: AD=KAD+X1AD*ρ+X2AD*ρ2+X3AD*ρ3+X4AD*AV+X5AD*AV2+X6AD*AV3+X7AD*ρ*AVwhere:AD is the assigned assay value that is a value and/or property representative of an elemental composition value, a physical property or an indicative property;AV is the analytical value of the oil sample;ρ is the density of the oil sample; andKAD, X1AD, X2AD, X3AD, X4AD, X5AD, X6AD and X7AD are constants.

18. The system of claim 17, wherein the analytical value is a LIF spectroscopy index based upon a summation of fluorescence intensity over the range of wavelengths used in LIF spectroscopy of the oil sample.

19. The system of claim 17, wherein the analytical value is a LIF spectroscopy index (LIFI) obtained by a function: LIFI=∑ω=ω1ω2FIω106where:ω is the wavelength of light,FIω is the fluorescence intensity of the oil sample for peaks detected at wavelengths over the range from ω1 to ω2, in arbitrary units,ω1 is a beginning wavelength of light, andω2 is an ending wavelength of light.