Quantitative 13C NMR spectra of kerogen other dominant chemical functional groups.

1. Assessing Source Rock Potential Using
Solid-State 13C NMR Organic
Geochemical Approaches
• By Charlie Keracik

2. Acknoledgements
• Baylor University
– Dr. William Hockaday
– Dr. Steven Driese
– Dr. Don Parker
– Dr. Forman
– Todd Longbottom
– Ken Bolling

3. Content
• Research Objectives
• Motivation
• Source rock evaluation methods.
• Goals of Study
• Results
• Conclusions

4. Objectives
• To relate structural characteristics of the
organic matter in source rocks to their
pyrolysis behavior during Rock-Eval™.
• Develop a predictive relationship for
estimating hydrocarbon potential using highly
correlated chemical parameters.

5. Motivation
Oil Shale
Commercialization
-Provides 91% of
Estonia's electricity.
-Full Industry Complex
50,000bpd in Utah by
2024.
- EcoShale™ In-
Capsule Process
expected to produce
400 million barrels of
oil over next 20
years.
-First major
production in North
America in decades
Not shale
oil.

6. SOURCE ROCK EVALUATION
• What is a source rock? • A sediment containing
sufficient organic
matter to be a future
source of
hydrocarbons.

7. Classification of organic matter in
source rocksLacustrine Deposit
High H/C and low O/C
Terrestrial Deposit (humic
coals)
Low H/C and high O/C

8. Chemical structure of kerogen (Type I)
Long Aliphatic
chains
Low aromatic
content.

9. Chemical structure of kerogen (Type II)
Medium aliphatic
chains.
Increased
aromatic content.

10. Chemical structure of kerogen (Type
III)
High aromatic
content.
Short aliphatic
chains.

11. Rock-Eval pyrolysis ™

12. Thermal degradation of kerogen

13. Solid-State 13C NMR
Fig. 13C CP NMR spectra layout and functional groups.
Values were obtained by
cross polarizarion13C NMR
spectroscopy, data from:
Bushnev et al., 2009

14. Hypothesis
• Hydrocarbon potential (S2) is linked to:
– 1. Total organic carbon (TOC %wt)
– 2. Intensity of aliphatic carbon peaks <90ppm
• dipolar-dephasing 13C NMR spectra is linked
to:
– 1. Free hydrocarbons already generated (S1)

15. How do structural characteristics of
kerogen affect pyrolysis products?
• Area of study
• Location: Woodway,
TX
• Formation: Eagle
Ford Shale
• 9 samples
• TL-1-9

16. 13C Nuclear Magnetic Resonance
• 300 MHz Solid-State Nuclear
magnetic resonance
spectroscopy.
• Cross Polarization and
Dipolar-Dephasing
experiments performed on
each sample.

17. Quantitative 13C NMR spectra of kerogen
Fig. Solid-state 13C NMR Spectra of sample TL-8 obtained using the cross-polarization (upper)
and dipolar-dephasing (lower) techniques. Also identified in the spectra are several of the
dominant chemical functional groups.

18. Rock-Eval pyrolysis ™ results
TOC†(wt.%)
S1
(mg/g)
S2
(mg/ g)
S3
(mg/g)
Tmax
(ºC) %Ro
HI
(s2x100)/
(TOC)
OI
(s2x100)/
(TOC)
TL1 9.49 1.06 61.31 1.39 408 0.18 646 15
TL2 7.21 1.07 45.49 1.67 410 0.22 631 23
TL3 8.19 0.96 53.44 1.46 412 0.26 653 18
TL4 3.76 0.18 14.26 1.73 421 0.42 379 46
TL5 5.43 0.22 17.99 3.35 419 0.38 331 62
TL6 7.91 0.34 35.29 2.82 411 0.24 447 36
TL7 2.00 0.47 3.58 0.54 421 0.42 179 27
TL8 4.93 0.32 26.05 1.08 416 0.33 528 22
TL9 0.94 0.01 1.26 0.30 431 0.60 134 32
Rock Eval results for samples
TL-1 to TL-9, obtained from
GeoMark Labratories LTD.
TOC = total organic carbon,
data from Boling (2013) [8]

19. Kerogen quality plot relating TOC to
potential oil yields.
TL-1
TL-2
TL-3
TL-4 TL-5
TL-6
TL-7
TL-8
TL-90
10
20
30
40
50
60
70
80
0 2 4 6 8 10 12
PotentialOilYieldS2mgHC/gRock
Total Organic Carbon, TOC (wt %)
Type I: Oil Prone
Type III: Gas Prone
Mixed Type II / III:
Oil / Gas Prone
Type II: Oil Prone
Usually Marine

20. NMR measurements of chemical
structure to Rock-Eval pyrolysis products
s1 s2 s3 Tmax %Ro HI OI
fa
N -0.665 -0.755 -0.500 0.762 0.766 -0.792 0.120
fa
P -0.556 -0.491 -0.042 0.364 0.370 -0.585 0.171
fa
S -0.262 -0.484 -0.789 0.450 0.456 -0.475 -0.351
fa
B -0.663 -0.783 -0.554 0.880 0.881 -0.789 0.190
fal
0.491 0.467 0.201 -0.343 -0.349 0.576 -0.002
fal
H 0.461 0.365 -0.002 -0.249 -0.252 0.482 -0.069
fal* 0.461 -0.744 -0.618 0.855 0.852 -0.855 0.098
fal
O 0.182 0.434 0.588 -0.496 -0.499 0.456 0.065
Tabulated R values were
calculated by the Microsoft
Excel using CORREL function.
Values highlighted in red
show a strong positive
correlation (R>0.75)
Values highlighted in green
represent a strong negative
correlation (R<-0.75).