DDS-067 Chapter D [Back]

Comparison of Kinetic-Model Predictions of Deep Gas Generation

Contents
Introduction .
Acknowledgments
Methods

Basin Scenarios
Kinetic Models
Model/ Pyrolysis Terminology .
Extent of Reaction with Single Activation Energy and Frequency Factor
Extent of Reaction using Multiple Activation Energies or Frequency Factors
Amount of Gas Generated
Results
Kerogen to Gas
Source-Rock Oil to Gas
Reservoir Oil to Gas .
Discussion
Kerogen to Gas
Oil to Gas
Conclusions and Future Studies
References Cited .

Figures
1 - 7. Graphs showing:
1. Amount of C1-C5 gas generated from Type-I kerogen with increasing burial depth, according to open-pyrolysis and composite-pyrolysis at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y.
2. Amount of C1-C5 gas generated from Type-II kerogen with increasing burial depth, according to open-pyrolysis and composite-pyrolysis at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y.
3. Amount of C1-C55 gas generated from Type-IIS kerogen with increasing burial depth, according to open-pyrolysis and composite-pyrolysis at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y.
4. Amount of C1-C5 gas generated from Type-III kerogen with increasing burial depth, according to open-pyrolysis and composite-pyrolysis
at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y.
5. Amount of C1-C5 gas generated from Type-III kerogen with increasing burial depth, according to open-pyrolysis and composite-pyrolysis at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y.
6. Amount of C1-C5 gas generated from the cracking of oil in 16 different source rocks with increasing burial depth, according to anhydrous-pyrolysis model at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y
7. Amount of gas generated from the cracking of reservoir oil with increasing burial depth, according to anhydrous-pyrolysis and hydrous-pyrolysis models at geologic heating rates of 1 ° C/ m. y. and 10 ° C/ m. y

Tables
1. Summary of six gas-generation kinetic models considered in this study
2. Fractional gas yields assigned to discrete activation energies and single-frequency factors used by Behar and others ( 1997) to model gas generation from kerogen
3. Fractional C1-C4 gas yields assigned to discrete activation energies by Horsfield and others ( 1992) to model gas generation from the cracking of oil
4. Gaussian distributions and their calculated discrete distributions of activation energies ( a) with fractional C1-C5 gas yields from kerogens as predicted by the composite-pyrolysis model (Pepper and Corvi, 1995) ;
( b) with fractional C1-C5 gas yields from oil retained in mature source rocks as predicted by the anhydrous-pyrolysis model ( Pepper and Dodd, 1995) ; and
( c) with fractional methane ( C1) , ethane ( C2) , propane ( C3) , and butane ( C4) yields from Type-II kerogen in the New Albany Shale ( Devonian-Mississippian)
as predicted by the hydrous-pyrolysis model ( Knauss and others, 1997)
5. Maximum C1-C5 gas yields for different starting materials used in six kinetic models
6. Summary of gas generation curves for kerogens and oils ( figs. 1-6) with respect to yield, depth, time, and temperature for fraction of reaction values of 0.05, 0.25, 0.50, 0.75, and 0.99 at 1 ° and 10 ° C/ m. y. heating rates for each kinetic model
7. Amounts of gas generated from kerogen above and below deep gas depth of 15,000 feet/ 4,572 m
8. Amounts of gas generated from cracking of oil above and below deep gas depth of 15,000 feet/ 4,572 m
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