Comparison of Kinetic Analysis of Source Rocks and Kerogen Concentrates by Burhan andn Reynolds

7/27/2019 Comparison of Kinetic Analysis of Source Rocks and Kerogen Concentrates by Burhan andn Reynolds

1/26

UCRL-JC-H7269

PREPRINT

Comparison of Kinetic Analysis ofSource Rocks and Kerogen Concentrates

John G. ReynoldsAlan K. Burnham

HO

Zbf-

This paper was prepared for submittal toOrganic Geochemistry

May 10,1994

Thisisapreprintofapaper intended for publication in a journal or proceedings. Since

changes may be made before publication, this preprint is made available with the

understanding mat it will not be cited or reproduced without the pemtiMion of the

author.

OANCOPY


2/26

DISCLAIMER

Thh document was prepared as an account of work sponsored by aa ageacy of the

United Stales Government. Neither the United States Gonenuneot nor the University

of California nor any of their employe**, nukes aay warranty, express or Imatttd, or

assumes my legal liability or responsibility for the accuracy, completeness, or aaefmV

aess of aay information, apparatus, product, or process disclosed, or it pre wars that

its use would not infringe privately owned rights. Reference herein to aay specific

commercial products, process, or service by trade name, trademark, manufacturer, or

otherwise, does not necessarily constitute or imply its endorsement, recomiattmafiott,

or favoring by the United States Government or the University of California. The

views and opinions of authors expressed herein do not necessarily state or reflect

those of the United States Government or the University of California, and shall not

be used for advertising or product endorsement purposes.


3/26

*

COMPARISON OF KINETIC ANALYSIS OF

SOURCE ROCKS AND KEROGEN CONCENTRATES

John G. Reynolds and Alan K. Burnham

University of California

Lawrence Livermore National Laboratory

Livermore, CA 94551

ABSTRACT

Shales and kerogen concentr ates from th e Green River, Rundel,

Ohio, Kimmeridge, and Phosphoria formations were examined byPyromat II micropyrolysis and kinetic parameters were

determined by the shif t - in-T m a x , d i s c r e t e d i s t r i b u t i o n ,

modified Friedman, and modified Coats-Redfern methods.

Overall, the shales and corresponding kerogens exhibited very

simi lar k ine t i c paramete rs . AP22, Ramsey Cross ing , and Ohio

shales and kerogens exhibited principal discrete activation

ene rgi es of 54 to 57 kcal/mol, narrow d i s t ri b ut i on s , and Tmax

at 25C/min heat ing r a t e around 480C. Kimmeridge and

Phosphoria shales and kerogens exhibited kinetic parametersty pi ca l of type II source rocks pr in ci pa l di s cr e te

ac t iva t ion energ ies of 54 to 57 kca l /mol , b road

di st r i bu t i on s, and Tmax at 25C/min around 459C.

The discrete distr ibution kinetic parameters were use to

calculate oil generation at laboratory and geological heating

r a t e s . Each shale and correspondi ng kerogen ex hi bi te d

generation curves and 50% generation temperatures that werevery si mi la r. The pr in ci pa l di ffe re nc e was the kerogens

exhibited more oil generation at low temperatures compared to

th e corresponding sha l es . Some kerogens ex hi bi te d curve s

which were also shifted to slightly lower temperatures than

the corresponding shales.

1


4/26

I (!

For these specific shales and kerogens, the results indicate

that kerogen isolation does little to effect the pyrolysis

kinetic parameters, therefore kerogen isolation may not be

necessary to derive valid kinetic parameters for some, and

perhaps most, samples.

INTRODUCTION

Kerogen pyrolysis kinetics has been the subject of much

research in recent years with the incorporation of laboratory

pyrolysis methods such as Rock Eval, hydrous,

thermogravimetric and more recently Pyromat pyrolysis to

provide data for various oil maturation models. High quality

kinetic analysis (and derived activation energy parameters)is essential for these models because of the need to

extrapolate from fast heating rates and high temperatures

found in the laboratory measurements to very slow heating

rates and relatively low temperatures found for the

geological extrapolation. Success of all this is, of course,

relies on the ability to accurately measure pyrolysis

behavior in the laboratory. In addition, this resulting data

must be generated under condition by which it can be

interpreted and translated to have geological relevance.

Whether laboratory pyrolysis can truly mimic geological

maturation still is debated.

One important and very practical issue is can kerogen

kinetics be measured on the \*'hole source rock or shale to

give meaniful results, or should these kinetics be measured

on kerogen concentrates where the mineral matter has been

chemically removed. . The effect of added mineral matter

common to many shale deposits on laboratory pyrolysis has

been studied in some detail alumina, bentonite, kaolinite,

calcite, illite, montmorillonite, quartz, dolomite (Horsfield

and Douglas, 1981), (Dembicki et al., 1983), {Katz, 1983),

{Dembicki, 1991). Evidence indicates that mineral matter may

?


5/26

affect pyrolysis through pyrolysate yield and compound

distribution changes. What is not clear is the effect of

mineral matter on kinetic parameters. Dembicki (1991) found

that added mineral matter affected the kinetic parameters

found for kerogen concentrate pyrolysis, but it is not clear

if the study was looking at real effects or statistical

scatter, since the Umax was not affected significantly. Other

comparison studies between isolated kerogens and

corresponding source rocks have shown, in some cases, little

differences in the derived kinetic parameters (Jarvie and

Lundell, 1993).

To address this unresolved issue, we present the laboratorykinetic analyses by the Pyromat II micropyrolyzer of five

shales and related kerogen concentrates. The kinetic

parameters derived for the shales are compared to the

corresponding concentrate. In addition, the kinetic

parameters are utilized to extrapolate to geological

conditions to compare at what temperature ranges oil

generation is predicted to occur.

EXPERIMENTAL

Samples. Selected elemental analyses of the shale samples

are shown in Table 1. Some of these analyses have been

reported previously (Reynolds et al., 1991), (Reynolds and

Murray, 1991). All the analyses are on the whole, not dried

sample, so therefore the wt % C and wt % H include sources

other than organic. C, H, and N were done on a Leco 600

analyzer and wt % S on a Leco SC 132 analyzer. Wt % CO2 wasmeasured directly by acid treatment of the shale.

AP22 was from the Green River formation (Anvil Points Mine,

Colorado); Ramsey Crossing was from the Rundel Deposit

(Australia) , Ohio (Devonian) was from a Lower Huron member

core sample (3000 - 3800 ft) from well 20336 in Martin Co.,

3


6/26

KY and was provided by George Claypool; Kimmeridge was from

the Draphne formation in the North Sea and was provided by

Birger Dahl (Norsk Hydro); and Phosphoria was from the Retort

Mountain Quarry in Beaverhead, Montana, and was provided by

George Claypool (USGS); kerogen concentrates were provided by

Alain Samoun (Lab Instruments).

Kinetic Analysis. The method of kinetic analysis using the

Pyromat II has been described in detail elsewhere (Braun et

al., 1991). The Pyromat II micropyrolyzer (Lab Instruments,

Kenwood, CA) measures hydrocarbon evolution utilizing a FID

detector. Normal sample size was approximately 4 mg (for

kerogen) to 10 mg (for shales). The temperature was measure

directly with a thermocouple in the center of -he sample

loaded in a quartz crucible. Kinetics were determined from

multiple runs at constant heating rates (nominally) three

50C/min, one 7C/min, and two lC/min runs were performed

for each kinetic data set. If Tmax values (temperature of

maximum rate of evolution) and profile shapes were not in

agreement, more runs at these heating rates were performed.

Kimmeridge and Phosphoria shales were examined previously

(Braun et al., 1991) using four heating rates (nominally 1,4, 15, and 50cC/min). Rate data were analyzed by using the

regression analysis program KINETICS (Burnham et al., 1987),

which contains several methods of accounting for a reactivity

distribution. The kinetic parameters used in this study were

determined by the shift-in-Tmax (yielding Aapprox and EapProx)

(Braun et al., 1991), modified Friedman (Friedman, 1963),

modified Coats-Redfern (Coats and Redfern, 1964), and the

discrete distribution (yielding Adiscrete a nd Ediscrete) (Braun

et al., 1991) methods.

RESULTS

Kinetic Analyses. Table 2 shows the complete listing of the

Friedman analyses for the shales and corresponding kerogens.

4


7/26

The Friedman method is a fairly simple approach which assumes

the reaction rate is a function of conversion and

temperature. Activation energy is determined as a function

of conversion with no assumptions required about the

frequency factor. Comparing the 50% extent of reaction

activation energies (E5o%Frie


8/26

Crossing shale exhibited plausible values of n and A (0.8 and

5-5 X 1014 respectively). However, the width of the reaction

profile is broader than a first-order reaction, requiring n >

1 for a single reaction, so the method is not internally

consistant. The other samples did not exhibit reasonablevalues, probably indicating that an n-th order reaction was

not being strictly followed.

The data was also examined by a modified Coats-Redfern (1964)

type analysis. The results for all the shales and kerogens

are listed in Table 3. The behavior is in good agreement

with the values calculated by the Friedman method. The 50%

extent of reaction activation energy values (ESO%C-R) frAP22

and Ohio shales and corresponding kerogens are within

experimental error, while the largest differences are

exhibited by the Kimmeridge shale and kerogen.

The behavior of the activation energy (calculated by the

Coats-Redfern method) as a function of extent of reaction for

the samples was very similar co that of Figure 1, with the

shales and corresponding kerogens being in close agreement.

Figure 2 shows the activation energy distribution calculated

by the discrete method and the associated frequency factors

as well as the activation energies and frequency factors

calculated by the shift-in-T^ax method for the shales and

kerogen concentrates. Figure 3 shows the evolution data for

the three different heating rates and the calculated fits of

that data from the discrete distribution analyses. Also

shown are the residuals of the least squares of the fits. Si

is the sum of the squares of weighted normalized rateresiduals, and L2 is the sum of the squares of weighted

integrated rate residuals. Casual inspection of Figure 2

shows immediately that, in most cases, there is good

agreement between the kinetic parameters of the shale and the

corresponding kerogen concentrate. Casual inspection of

6


9/26

f

Figure 3 shows that the fits generated by the discrete

distribution agree very well with the generated data.

Table 4 summarizes the energies of activation of each sample

for convenience. Listed are Eapprox, principal discrete/

Eso%Friedman, and Eso% c-R- Also included is the calculated

(from the discrete distribution method) Traax at the 25C/min

heating rate.

The Eapprox, principal Ediscrete/ E50%Friedman/ and Sso%c-R are

all within experimental error for each shale and kerogen in

most cases. The exceptions are: the Eso%Friedman fr tn e Ohio

shale and Kimmeridge kerogen, and the Eso%c-R fr tne

Kimmeridge shale and Ohio kerogen are slightly higher than

the corresponding Eappr0x and principal Ediscrete*T n e

calculated Tmax at 25C/min heating rate differ by 3 C or

less in all cases.

The distributions in Figure 2 show some slight differences

between the shales and the corresponding kerogens. The a

value for the Ohio shale is much noticably than for the

kerogen. The shale exhibited early evolving material(Figure

3) which was intense enough in the lC/min profile that it

was deleted for the fitting procedure. This could

artificially affect a.

This low temperature evolving material could be due to a

variety of sources -- primarily unextracted bitumen and/or

mineral effects. Unextracted bitumen has been shown to

affect kinetic parameters derived from Pyromat II

measurements in shales (Reynolds and Murray, 1991), coals

(Reynolds and Burnham, 1993) and tar sands (Reynolds,

manuscript in preparation), primarily through broadening of

and coevolution with the principal pyrolysis peak. This

sample is particularly lean, which may be resonsible for a

7


10/26

higher relative abundance of the bitumen. The effects of

mineral matter will be discussed below.

The Kimraeridge kerogen has a broader distribution than the

shale. This difference does not appear to be reflected inother parameters, including the quality of fits (Figure 3)

and calculated Tmax at 25C/min. However, in might be some

indication that there is a difference in some cases between

shale and corresponding kerogen samples.

Phosphoria shale and kerogen have discrete energy

distributions which are slightly different, which could

reflect difference in having mineral matter present or not.

However, both distributions are broad, and it would be

speculative at best to ascribe matrix effects to these minor

differences.

Oil Generation. Figure 4 shows the oil generation curves for

the shales and corresponding kerogens calculated from the

discrete distribution data at laboratory (lC/min) and

geological (3 C/m.y.) heating rates. In each figure, the

shale oil generation is indicated by solid lines, while thecorresponding kerogen oil generation is indicated by the

dashed line.

The AP22 shale and kerogen generation curves are almost

identical for both laboratory and geological heating rates.

The kerogen has a little more low temperature evolving

material which is imaginatively apparent when comparing the

discrete distributions and evolution data (Figures 2 and 3).

The Ramsey Crossing shale and kerogen have very similar

generation curves at l0C/min, with the kerogen slightly

shifted to lower temperatures compared to the shale (this is

also seen in the lower calculated T^* at the 25C/min heating

rate shown in Table 4). At the geological heating rate, the

8


11/26

generation curves are also almost identical in shape, but as

in the laboratory case, the kerogen is shifted to slightly

lower temperatures compared to the shale.

The Kimmeridge and Ohio samples have almost identical

generation curves except for a little more early evolving oil

generated from the Kimmeridge kerogen in both laboratory and

geological heating rates.

At the laboratory heating rate, the Phosphoria kerogen has

more notable oil evolution at lower temperatures than the

shale, but eventually behaves identically as the shale

towards the end of the oil generation. The broad discretedistribution of the kerogen has more intense low energy

contributions than the shale, but has a similar pattern for

the high energy contributions which can account for this

behavior. The oil generation at 3C/m.y. heating rate shows

the kerogen and shale are much more similar, with the kerogen

crossing over the shale at approximately 30% generation.

This is consistent with the kerogen having a slightly higher

principal Ediscrete-

DISCUSSION

From the kinetic parameters above, and the oil generation

curves shown in Figure A, the shales and the corresponding

kerogen concentrates behave very similarly. In all cases and

at both the laboratory and geological heating rates, the

kerogens exhibited more initial oil generation than the

corresponding shale, and in some cases, the oil generationcurves of the kerogens are slightly shifted from the

corresponding shale. However, these differences are minor,

indicating for this limited data set, the kerogens behave

essentially the same as the shales in pyrolysis kinetic

determinations.

9


12/26

J a r v i e and Lundell (1993) have re po rt ed th e di ff er en ce s

between whole rock and kerogen kinetics determined by Rock-

Eval using a discrete distribution method for a Naples Beach

ou tc ro p sample from the Monterey (Miocene) format ion. The

whole rock had a p r inc ipa l E^iscrete of 55 kca l/mol (12% of

the distribution) and a Adiscrete of 2.12 X 1015

1/sec. The

kerogen concentrate had a principal Eaiscreteof

53 kcal/mol

(12% of th e dis t r ibu t ion) and a A


13/26

/

parameters by pyrolyzing mixtures of sedimentary minerals

with varying concentrations of a kerogen isolated from a

Kimmeridgian black shale. The kinetic parameters derived

indicated, at low concentrations, that quartz, calcite, and

dolomite shifted the activation energies to higher values,

while montmorillonite shifted the activation energy to lower

values than observed for the isolated kerogen. The minerals

which shifted the activation energies to higher values were

considered to be due to retention of pyrolysate, while the

minerals which shifted the activation energies to lower

values were considered to be due to catalytically assisted

pyrolysis.

Our results on the limited number of samples examined

indicates that kerogen isolation has very little effect on

parameters when determining overall pyrolysis kinetics. The

implication is that isolation of the kerogen from the shale

is not necessary when determining these types of kinetics.

Whether mineral matrix effects mentioned above indicate

isolation of kerogen is necessary for valid kinetics is not

obvious. Isolating the kerogen from the rock matrix does

cause a change in the kerogen-rock interaction because of theremoval of naturally formed associations between the two.

Because these associations have to be somehow important in

diagenesis, removing them by kerogen isolation may not be all

that appropriate. However, the chemical effects of the

mineral matrix probably are a lot different at reservoir

temperatures and geological heating rates than in laboratory

pyrolysis. Regardless, our results show for the samples in

this study, there is essentially no difference between

kinetic parameters determined on the whole rock or the

isolated kerogen, and that for these types of kinetic

determinations, the arguments about mineral matrix effects

probably do not apply.

11


14/26

CONCLUSIONS

The examination of the pyrolysis behavior of selected Green

River, Rundel, Ohio, North Sea, and Phosphoria shales and

isolated kerogen concentrates shows that the derived kineticparameters and calculated oil generation curves are very

similar between the shale and the corresponding kerogen.

These results indicates that in some cases, kerogen isolation

is not necessary to determine valid pyrolysis kinetics on a

whole rock sample.

ACKNOWLEDGMENTS

We thank Ann M. Murray of Lawrence Livermore National

Laboratory for experimental assistance and Alain Samoun of

Lab Instruments, Inc., for the kerogen concentrates. This

work was performed under the auspices of the U. S. Department

of Energy by the Lawrence Livermore National Laboratory under

Contract No, W-7405-ENG-48. Partial support came from the

office of Basic Energy Sciences and a group of industrial

sponsors.

REFERENCES

Braun, R. L., Burnham, A. K., Reynolds, J. G. and Clarkson,

J. E. (1991) Pyrolysis kinetics for lacustrine and marine

source rocks by programmed micropyrolysis. .Energy and

Fuels, 5, 192-204.

Burnham, A. K., Braun, R. L., Gregg, H. R. and Samoun, A. M.

(1989) Comparison of Methods for Measuring Kerogen Pyrolysis

Rates and Fitting Kinetic Parameters. Energy and Fuels 3,

42-55.

Coats, A. W. and Redfern, J. P. (1964) Kinetic parameters

from thermogravimetric data. Nature 201, 68-69.

12


15/26

Delvaux, D., Martins, H., Leplat, P., and Paulet, J. (1990)

Comparative Rock-Eval pyrolysis as an imoproved tool for

sedimentary organic matter analysis. Adv. Org. Geochem. 16(4-

6),1221-1229.

Dembicki, H., Jr., Horsfield, B., and Ho, T. T. Y. (1983)

Source Rock Evaluation by Pyrolysis-Gas Chromatography. AAPG

Bull. 67(7), 1094-1103.

Dembicki, H., Jr. (1991) The effects of the mineral matrix on

the determination of kinetic parameters using modified Rock-

Eval pyrolysis. Org. Geochem. 18(4), 531-539.

Espitalie, J., Madec, M., and Tissot, B. (1980) Role of

mineral matrix in kerogen pyrolysis: influence on petroleum

generation and migration. Bull. Am. Assoc. Pet. Geol. 64,

59-66.

Friedman, H. L. (1963) Kinetics of thermal degredation of

char-forming plastics from thermogravimetry. Application to

a phenolic plastic. J. Polym. Sci., Part C 6, 183-195.

Horsfield, B. and Douglas, A. G. (1981) The influences of

minerals on the pyrolysis of kerogens. Geochim. Cosmichim.

Acta 44, 1119-1131.

Jarvie, D. M. and Lundell, L. L. (1993) Hydrocarbon

generation and kinetics of the Monterey formation. In USGS

Cooperative Monterey Organic Geochemistry Study, C. M.Isaacs, Ed.

Katz, B. J. (1983) Limitations of 'Rock Eval' pyrolysis for

typing organic matter. Org. Geochem. 4(3/4), 195-199.

13


16/26

Klomp, U. C. and Wright, P. A. (1990) A new Method for the

measurement of kinetic parameters of hydrocarbon generation

from source rocks. Adv. Org. Geochem. 16(1-3), 49-60.

Orr, W. L. (1986) Kerogen/asphaltene/sulfur relationships in

sulfur-rich Monterey oils. Org. Geochem. 10, 4 99-516.

Peters, K. (1986) Guidlines for evaluating petroleum source

rock using programmed pyrolysis. AAPG Bui. *70(3), 318-329.

Rose, H. R., Smith, D. R., Quezada, R. A., Hanna, J. V., and

Wilson, M. A. (1993) Role of minerals and additives duriong

kerogen pyrolysis. Fuel Proces. Tech. 33, 149-157.

Reynolds, J. G. and Burnham, A. K. (1993) Pyrolysis Kinetics

and Maturation of Coals from the San Juan Basin. Energy and

Fuels, 7(5), 610-619.

Reynolds, J. G., Burnham, A. K. and Mitchell, T. 0. (1994)

Kinetic Analysis of California Petroleum Source Rocks by

Programmed Temperature Micropyrolysis, submitted Org.

Geochem.

Reynolds, J. G., Crawford, R. W. and Burnham, A. K. (1991)

Analysis of Oil Shale and Petroleum Source Rock Pyrolysis by

Triple Quadrupole Mass Spectrometry: Comparisons of Gas

Evolution at the Heating Rate of 10C/min. Energy and Fuels,

5, 507-523.

Reynolds, J. G. and Murray, A. M. (1991) Pyromat II

micropyrolysis of source rocks and oil shales: effects of

native bitumen content content and sample size on Tmax values

and kinetic parameters. Lawrence Livermore National

Laboratory Report UCRL-ID106505 January.

14


17/26

Table 1. Selected Chemical Analyses for Shales

Sample C,w t% H, wt % N,wt% S,wt% CC>2,wt% TQ C/wt%

AP22 16J0 TI 53 03 22l 9SRamsey Crossing

Ohio 3.6 0.8 0.3 2.4 0.8 3.4Kimmeridge 6.4 1.5 0.4 3.3 0.8 6.2Phosphoria 16.8 2.2 0.8 1.8 OS 16.6

All samples were ground/ whole, and not dried before analyses.


18/26

Table 2. Friedman Analyses Tor Selected Shales and Kerogens

A (1/sec) E(kcal/mol) A (1/sec) E(kcal/mol) A (1/sec) E(kcal/mol) A (1/sec) E(kcal/mol) A (1/sec)

AP22 Shale Ramsey Crossing Shale Oil Shale Kimmeridge Shale Phosphoria

6.84 x 1013

7.02 x 1013

9.73 x 10131.51 x 1014

1.93 x 1014

3.22 x 1014

5.44 x 1014

1.57x1015

2.70 x 10lfi

52.8 (2.6)

53.3 (0.5)

54.0 (0.7)54.7 (0.5)

55.0 (0.5)

55.7 (0.2)

56.5 (0.0)

58.0 (0.6)

62.6(1.1)

6.86x1014

3.96 x 1014

4.40 x 1014

6.05 x 1014

6.94 x 1014

8.82xl0l4

1.08x1014

1.08 x 1014

6.22 x 1014

56.4 (3.0)

56.3(1.6)

56.6 (0.7)57.1 (0.4)

57.4 (0.2)

57.8(0.1)

58.3 (0.4)

58.7 (1.0)

58.4(1.6)

3.40x1010

2.43 x 1017

5.22 x 10143.57 x 1014

4.47 x 1014

6.72 x 1014

1.38x1015

5.58x1015

7.87 x 1015

41.6(79.8)

64.4 (2.5)

56.6 (0.4)56.3 (0.8)

56.7(1.5)

57.4 (2.0)

58.6 (2.9)

61.1 (4.9)

62.5 (7.8)

3.29x1012

3.33x1013

2.09x1014

5.01 x 1014

9.08 x 1014

1.71 x 1015

4.89 x 1015

1.07 x 1016

5.70 x 1015

48.0(1.8)

51.3 (0.6)

54.0(1.1)55.4 (1.5)

56.4 (1.8)

57.6 (2.2)

59.4 (2.2)

61.0 (2.3)

61.0 (2.5)

3.50 x 10]5

8.90x1014

1.31x1015

6.80 x 1014

7.30 x 1014

4.15 xlO' 4

3.14x1014

8.18x1014

2.03 x 1015

AP22 Kerogen Ramsey Crossing Kerogen Ohio Kerogen Kimmeridge Kerogen Phosphoria

2.99 x 1014

2.51 x 1014

3.97 x 1014

1.90x1014

1.27x1014

1.13x1014

1.23x1014

2.63 x 1014

2.68 x 1014

54.4 (3.4)

54.9 (1.5)

55.8 (0.4)

54.9 (0.7)54.5 (0.9)

54.4 (1.3)

54.5 (1.2)

55.7 (1.3)

59.3 (1.9)

6.07 x 1010

1.30x1014

5.89 x 1014

5.18x10144.79 x 1014

5.31 x 1014

7.32 x 1014

1.69x1015

1.80 xlQi6

42.9 (5.2)

54.0 (2.0)

56.5 (0.4)

56.5(0.1)56.5 (0.3)

56.8 (0.6)

57.4(1.0)

58.8(1.6)

62.8 (3.2)

1.96x1021

4.95 x 1015

4.85x1014

1.85x10141.46 x 1014

1.29xl0l 4

2.84 x 1014

6.73 x 1014

1.24 xlO1 4

74.3 (43.5)

59.2 (4.3)

56.4(1.8)

55.1 (0.5)54.8 (0.5)

54.6 (0.7)

55.9(1.5)

57.5(1.0)

56.0 (3.4)

1.37x1019

2.83 x 1015

6.50x1014

4.64x10143.96 x 1014

4,93 x 1014

9.66x1014

3.59x1015

2.10x1015

67.4 (2.9)

57.0 (0.7)

55.3(1.1)

55.1 (1.4)55.1 (1.5)

55.6(1.9)

56.9 (2.4)

59.2 (3.3)

59.3 (2.8)

5.46x1018

1.78 x 1016

6.49x1015

5.75 x 10154.99 x 1015

7.05x1015

9.78 x 1015

6.56x1015

1.95x1015


19/26

Tabl e 3. Coats-Redfern Analyses for Selected Shales and Kerogens

A(l/sec) E(kcal/mol) A (1/sec) E(kcal/mol) A (1/sec) E(kcal/mol) A (1/sec) E(kcal/mol) A (1/scc)

AP22 Shale Ramsey Crossing Shale Ohio Shale Kimmeridge Shale

5.13 x 10"6.97 x 10

14

3.22 x 1014

2.15 xlO1.45 xlO

14

1.01 x 1014

6.94 x 10^34.66 x 10>3

4.27 x 10"

53.5 (6.5)53.1 (2.6)

53.4 (1.2)

53.9 (0.6)54.3 (0.2)54.7 (0.0)

55.1 (0.0)

55.6 (0.0)57.2 (0.5)

5.11x1015

3.62 x 10*5

1.75x10"

1.04 x 10"6.61 x 10

14

4.14 x 10

2.36 x 1014

1.25 xlO14

4.08 x 1014

54.0 (2.5)55.9 (2.5)56.3(1.6)

56.6(1.1)57.0 (0.8)57.2 (0.5)57.5 (0.3)57.8 (0.0)

58.1 (0.4)

8.55 x

4.02 x2.89 x

2.86 x3.56 x1.05 x4.72 x

2.90 x2.16 x

100

10251018

10*10"

10"

10*4

1014

1014

9.8 (133.5)85.6 (7.3)65.7(1.5)

60.8 (0.9)59.0 (0.9)58.3(1.2)58.3 (1.6)58.9(2.1)

60.5 (4.7)

1.11 x 1014

6.87x10"9.20xlO!3

1.32 xlOl41.67 x 10

14

1.74 xlOl4

2.22 x IOI4

2,76 xlO14

1.97 x 1014

48.4 (4.6)49.4 (2.5)

50.9 (1,8)

52.4(1.7)53.6 (1.7)54.6(1.9)

56.0 (1.9)57.7 (2.3)59.3(1.8)

Phosphoria

8.44x10162.47 x 10

]6

9.16x10"

2 .85x10"1.60x1015

3.91 x 1014

1.84 xlOl4

9.12 x 10138.08x10"

AP22 Kerogen Ramsey Crossing Kerogen Ohio Kerogen Kimmeridge Kerogen Phosporia K

1.24x1017

4.03x1015

1.53X10"

7.16 xlOl4

3.09 x 10l4

1.34 xlOl4

6.02 x 1013

2.76 x 1013

1.34x1013

57.2 (6.4)

55.2 (3.0)

55.3(1.9)

55.4(1.3)

55.3(1.1)

55.1(1.1)54.9(1.2)

55.0(1.2)

55.7 (0.5)

8.23 x 109

1.19x 10"

1.74 xlO14

2.94 x 10M

2.84 xl0i 4

2.18 xlO14

1.47 x 1014

9.67 x 1013

8.30x1013

35

47

52

54

55^

5556

57,

58,

5 (8.0)

.3 (5.2)

.3 (3.0)

3(1.8)

2(1.1)

8 (0.6)3 (0.1)

0(0.4)

6(1.4)

3.38 x 1026

2.74 x 1020

1.85 x 1017

1.08 x 1016

2.02 x 10"

5.06 xlO1.84 xlOl

4

8.19 xlO1 3

2.95 x 1013

84.0 (74.9)

70.0(12.0)

62.1 (5.5)

59.4 (3.3)

58.1(2.2)

57.1 (1.6)56.7(1.4)

56.7(1.4)

57.3 (0.4)

2.38 x 1025

3.19 x 1018

5.34 x 1016

6.41 x 1015

1.60x1015

5.89 xlOl4

2.84 x IOI4

1.90 xlOl4

1.25 xlO

80.4 (5.2)

62.9 (0.2)

59.0 (0.8)

57.3(1.0)

56.4(1.2)

56.1 (1.3)56.2(1.6)

57.0 (2.1)

58.4 (2.7)

3.55 x 1022

1.58 xlO1 8

1.04 xlO1 7

2.57 x 1016

9.80 x 1Q15

5.22x10"

3 .26x10"

1.70x10"

3.24 x 1014


20/26

Table 4. Summary of activation energy values for shales and kerogens determined by th shift-in-Tmax (Eapprox) / discrete distribution


21/26

FIGURE LEGENDS

Figure 1. Activation energy (determined by the Friedman

method) as a function of extent of reaction for: AP22 shale

- i AP22 kerogen , Ramsey Crossing shale ,

Ramsey Crossing kerogen y Ohio shale , Ohio

kerogen , Kimmeridge shale --, Kimmeridge kerogen

Phosphoria shale , Phosphoria kerogen .

Figure 2, Kinetic parameters determined by discrete

distribution and shift-in-Tmax methods, comparing shales and

kerogens.

Figure 3. Experimental data at selected heating rates andcalculated fits (determined by discrete distribution method)

comparing shales and kerogens. (Nominal heating rates for

Kimmeridge and Phosphoria shales: 1, 4, 15, and 50C/min; all

others: 1, 7, and 50C/min.)

Figure 4. Calculated oil generation curves (using discrete

distribution kinetic parameters) for shales (solid lines) and

kerogens (dotted lines) at the laboratory heating rate of

lC/min, and geological heating rate of 3C/m.y.


22/26

Figure 1

o

e

< 5

cLUc

oCO>o-.^y=^Vf:X-

/

0.2 0.4 0.6

Fraction Reacted

0.8


23/26

Figure 2

8 0 -

6 0 -

4 0 -

2 0 -

AP22Oil Shale

2.1 X1014

I/Sec

0 - r

Eapprox =

53.7 (1.0) kcal/mol

Aapprox=

7.5 X1013

1/sec

a ' 0 . 0 % of Eapprox

6 0 -

4 0 -

2 0 -

T T

AP22Kerogen

Atfscrele-

9.7Xl013

1/sec

""11

3 =-

Eapprox=

53.5 (0.9) kcal/mol

^approx "

6.2 X1013

1/sec

0 = 1.4% Of Eapprox

_ _

1 1 1 1

4 0 -

3 0 -

2 0 -

Ramsey CrossingOil Shale

^discrete =

8.1 X1014

1/sec

Eapprox*56.8 (0.8) kcal/mol

appro* ~

5.1 X1014

1/sec

.a

5 0 -cul 4 0 -

*Z 3 0 -o

5s

2 0 -

1 0 -

0 -

Ramsey CrossingKerogen

Adtscretes

4.4 X 10t 4

i/sec

OhioKerogen

Adiscrele

2.1 X1 014

1/sec

4 0 -

3 0 -

2 0 -

1 0 -

KimmeridgeKerogen

^discrete =

2.6X1014

1/sec

I S -_ PhosphoriaKerogen

1 0 -

5 -

Adiscwte-

3.0X1015

1ftec

eapprox *

56.3 (0.0) kcal/mol

Aapprox=

4.2 X1014

1/sec


24/26

Figure 3

200 250 300 350 4O0 450 500 550 600 200 250 300 350 400 450 500 550 600T*mp*raiurft, *C


25/26

Figure 4

250 350Tempefa'jj'*. C

550


26/26

Documents

Comparison of Kinetic Analysis of Source Rocks and Kerogen Concentrates by Burhan andn Reynolds