Characterization of crude oil by ultraviolet visible spectroscopy
A system and a method for determining one or more distillation temperatures for one or more given distillation weight percentages of a crude oil sample are provided, which can be used to produce a simulated distillation curve. Simulated distillation temperatures of crude oil samples are assigned as a function of density and data derived from UV/Visible spectroscopy measurement of the crude oil samples.
1. A system for assigning a simulated distillation temperature for a given distillation weight percentage to an oil sample based upon UV/Visible spectroscopy data, wherein the oil sample is selected from naturally occurring hydrocarbons derived from crude oils, bitumens, heavy oils or shale oils, wherein the oil sample is characterized by a density, wherein the oil sample is formed into an oil solution for spectroscopy, the system comprising:
a non-volatile memory device that stores calculation modules and data, the data including UV/Visible spectroscopy data indicative of absorbance peak intensity detected in a predetermined wavelength range for the oil sample;
a processor coupled to the memory;
a first calculation module that calculates and assigns a cumulative and normalized UV/Visible absorbance from the data indicative of absorbance values; and
a second calculation module that calculates and assigns a simulated distillation temperature for a given distillation weight percentage with a multi-variable polynomial equation with a set of predetermined constant coefficients developed using linear regression wherein the variables are the UV/Visible absorbance for the given distillation weight percentage, and the density of the oil sample.
2. The system as in claim 1 , wherein plural distillation temperatures are assigned to obtain a set of simulated distillation data.
3. The system as in claim 1 , wherein the given distillation weight percentage values are 0.5, 5, 10, 20, 30, 40, 50, 60, 70, 80 W %.
4. The system as in claim 1 , wherein the simulated distillation temperature is calculated as T DT using the equation:
T
DT
=
K
SD
+
X
1
SD
(
1
UVVWL
)
+
X
2
SD
(
1
DEN
)
+
X
3
SD
(
1
UVVWL
2
)
+
X
4
SD
(
1
DEN
2
)
+
X
5
SD
(
1
UVVWL
*
DEN
)
X
6
SD
(
1
UVVWL
3
)
+
X
7
SD
(
1
DEN
3
)
+
X
8
SD
(
1
UVVWL
2
*
DEN
)
+
X
9
SD
(
1
DEN
2
*
UVVWL
)
;
(
1
)
where:
DT is the distillation weight percentage, K SD , X1 SD , X2 SD , X3 SD , X4 SD , X5 SD , X6 SD , X7 SD , X8 SD and X9 SD are constants, DEN is the density of the sample (Kg/L), and UVVWL is the wavelength at DT.
5. A system for assigning a simulated distillation temperature for a given distillation weight percentage to an oil sample, wherein the oil sample is selected from naturally occurring hydrocarbons derived from crude oils, bitumens, heavy oils or shale oils, wherein the oil sample is characterized by a density, wherein the oil sample is formed into an oil solution for spectroscopy, the system comprising:
an ultraviolet visible spectrometer that outputs ultraviolet visible spectroscopy data derived from the oil sample,
a non-volatile memory device that stores calculation modules and data, the data including UV/Visible spectroscopy data indicative of absorbance peak intensity detected in a predetermined wavelength range for the oil sample;
a processor coupled to the memory;
a first calculation module that calculates and assigns a cumulative and normalized UV/Visible absorbance from the data indicative of absorbance values; and
a second calculation module that calculates and assigns a simulated distillation temperature for a given distillation weight percentage with a multi-variable polynomial equation with a set of predetermined constant coefficients developed using linear regression wherein the variables are the UV/Visible absorbance for the given distillation weight percentage, and the density of the oil sample.
6. The system as in claim 5 , wherein the oil sample is crude oil.
7. The system as in claim 5 , wherein the oil sample is obtained from an oil well, stabilizer, extractor, or distillation tower.
8. The system as in claim 5 , wherein plural distillation temperatures are assigned to obtain a set of simulated distillation data.
9. The system as in claim 5 , wherein the given distillation weight percentage values are 0.5, 5, 10, 20, 30, 40, 50, 60, 70, 80 W %.
10. The system as in claim 5 , wherein the simulated distillation temperature is calculated as T DT using the equation:
T
DT
=
K
SD
+
X
1
SD
(
1
UVVWL
)
+
X
2
SD
(
1
DEN
)
+
X
3
SD
(
1
UVVWL
2
)
+
X
4
SD
(
1
DEN
2
)
+
X
5
SD
(
1
UVVWL
*
DEN
)
X
6
SD
(
1
UVVWL
3
)
+
X
7
SD
(
1
DEN
3
)
+
X
8
SD
(
1
UVVWL
2
*
DEN
)
+
X
9
SD
(
1
DEN
2
*
UVVWL
)
;
(
1
)
where:
DT is the distillation weight percentage, K SD , X1 SD , X2 SD , X3 SD , X4 SD , X5 SD , X6 SD , X7 SD , X8 SD and X9 SD are constants, DEN is the density of the sample (Kg/L), and UVVWL is the wavelength at DT.
11. A method for operating a computer to assign a simulated distillation temperature for a given distillation weight percentage to a fraction of an oil sample based upon near infrared spectroscopy data, wherein the oil sample is selected from naturally occurring hydrocarbons derived from crude oils, bitumens, heavy oils or shale oils, wherein the oil sample is characterized by a density, wherein the oil sample is formed into an oil solution for spectroscopy, the method comprising:
entering into the computer UV/Visible spectroscopy data indicative of absorbance peak intensity detected in a predetermined wavelength range for the oil sample;
calculating and assigning a cumulative and normalized UV/Visible absorbance from the data indicative of absorbance values; and
calculating and assigning a simulated distillation temperature for a given distillation weight percentage with a multi-variable polynomial equation with a set of predetermined constant coefficients developed using linear regression wherein the variables are the UV/Visible absorbance for the given distillation weight percentage, and the density of the oil sample.
12. The method as in claim 11 , wherein plural distillation temperatures are assigned to obtain a set of simulated distillation data.
13. The method as in claim 11 , wherein the given distillation weight percentage values are 0.5, 5, 10, 20, 30, 40, 50, 60, 70, 80 W %.
14. The method as in claim 11 , wherein the simulated distillation temperature is calculated as T DT using the equation:
T
DT
=
K
SD
+
X
1
SD
(
1
UVVWL
)
+
X
2
SD
(
1
DEN
)
+
X
3
SD
(
1
UVVWL
2
)
+
X
4
SD
(
1
DEN
2
)
+
X
5
SD
(
1
UVVWL
*
DEN
)
X
6
SD
(
1
UVVWL
3
)
+
X
7
SD
(
1
DEN
3
)
+
X
8
SD
(
1
UVVWL
2
*
DEN
)
+
X
9
SD
(
1
DEN
2
*
UVVWL
)
;
(
1
)
where:
DT is the distillation weight percentage, K SD , X1 SD , X2 SD , X3 SD , X4 SD , X5 SD , X6 SD , X7 SD , X8 SD and X9 SD are constants, DEN is the density of the sample (Kg/L), and UVVWL is the wavelength at DT.
15. A method for assigning a simulated distillation temperature for a given distillation weight percentage to a fraction of an oil sample, wherein the oil sample is selected from naturally occurring hydrocarbons derived from crude oils, bitumens, heavy oils or shale oils, wherein the oil sample is characterized by a density, wherein the oil sample is formed into an oil solution for spectroscopy, the method comprising:
obtaining UV/Visible spectroscopy data indicative of absorbance peak intensity detected in a predetermined wavelength range for the oil sample;
entering into a computer the obtained UV/Visible spectroscopy data;
calculating and assigning a cumulative and normalized UV/Visible absorbance from the data indicative of absorbance values; and
calculating and assigning a simulated distillation temperature for a given distillation weight percentage with a multi-variable polynomial equation with a set of predetermined constant coefficients developed using linear regression wherein the variables are the UV/Visible absorbance for the given distillation weight percentage, and the density of the oil sample.
16. The method as in claim 15 , wherein the oil sample is crude oil.
17. The method as in claim 15 , wherein the oil sample is obtained from an oil well, stabilizer, extractor, or distillation tower.
18. The method as in claim 15 , wherein plural distillation temperatures are assigned to obtain a set of simulated distillation data.
19. The method as in claim 15 , wherein the given distillation weight percentage values are 0.5, 5, 10, 20, 30, 40, 50, 60, 70, 80 W %.
20. The method as in claim 15 , wherein the simulated distillation temperature is calculated as T DT using the equation:
T
DT
=
K
SD
+
X
1
SD
(
1
UVVWL
)
+
X
2
SD
(
1
DEN
)
+
X
3
SD
(
1
UVVWL
2
)
+
X
4
SD
(
1
DEN
2
)
+
X
5
SD
(
1
UVVWL
*
DEN
)
;
(
1
)
where:
DT is the distillation weight percentage, K SD , X1 SD , X2 SD , X3 SD , X4 SD , X5 SD , X6 SD , X7 SD , X8 SD and X9 SD are constants, DEN is the density of the sample (Kg/L), and UVVWL is the wavelength at DT.