Petroleum Generation
Petroleum Geology Class 745
Spring 2002
Istvan Csato
University of South Carolina
Department of Geological Sciences
I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
Sequence Stratigraphy
Controls on total organic matter
• Productivity
• Grain size
• Sedimentation rate
• Oxidation/Reduction
Preservation of Organic Matter
Demaison and Moore, 1980
Conversion of Organic Matter
• biopolymers
• bitumen
• biomarkers
Barker, 1996
I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
Conversion of Kerogen
Organic matter: 1%
• Kerogen 90%
• Bitumen 10%
Barker, 1996
Kerogen Evolution Paths
Tissot et al., 1974
Variation of the HC/TOC, Los Angeles and Ventura Basins
Philippi, 1965
Depths and Temperatures for Onset of Oil Generation
Tissot et al., 1975
General Scheme for Hydrocarbon Formation
Tissot et al., 1974
I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
Questions for exploration geologist:
1. Does the the rock have sufficient organic matter?
2. Is the organic matter capable of generating?
3. Has this organic matter generated petroleum?
4. Has the generated petroleum migrated out?
5. Is the rock oil-prone or gas-prone?
Quantity of Organic Matter:
TOC must be greater than 0.5%
Type of Organic Matter:
Maturity
Thermal Alteration Index, Paris Basin
Correia, 1971
Maturity
Kerogen Maturation Profile, Louisiana Gulf Coast
Vitrinite: woody, Type III kerogen
Barker, 1996
Maturity
Vitrinite Reflectance Data
Dow and O’Connor, 1982
Maturity
Vitrinite Reflectance Profile, Elmsworth Field, Canada
Welte et al., 1984
Disturbing of Vitrinite Reflectance
Barker, 1996
Elemental Data For Kerogen
Peters, 1986
Pyrolysis Increase of S1 with Depth
S2
S1
Tmax
Barker, 1996
Pyrolysis Yield of Hydrocarbons with Increasing Temperature
S2
S1
S2/TOC = HI
S3/TOC = OI
S1 S2
Tmax
Barker, 1974
Changes in TR and Tmax
Espitalie et al., 1977
HI versus OI
Peters, 1986
Evaluation of Geochemical Parameters
Peters, 1986
I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
Kinetics of Chemical Reactions
KER = BIT + RESIDUE
At t=0
KER= Vo, BIT=0
At t>0
KER=Vo-Vt, BIT=Vt
dV/dt= k(Vo-Vt)
k=A*e[-E/RT] Arrhenius equation
R =Gas constant (0.008314 KJ/mol0K)
T=absolute temperature
E=activation energy
A=frequency factor
Activation Energy
Barker, 1996
Bond Energies
March, 1985
Increasing Reaction Rate with Temperature
Barker, 1996
Bitumen Release Curves with Different Activation Energies
Barker, 1996
Bitumen Release Curves with Different Frequency Factors
Barker, 1996
Increase in Reaction Rate
Barker, 1996
Bitumen Release Curves for 8 Parallel Reactions
Juntgen and Klein, 1975
Distribution of Activation Energies, Paris Basin
Tissot et al., 1987
Temperature Factors used by Lopatin
Dmaturity = (Dti)(rni) TTI (Time-Temperature Index)
Barker, 1996
Burial History Plot
Barker, 1996
Calculated TTI
Barker, 1996
Calibration of TTI
Waples, 1980
Time-Temperature Reconstruction, Big Horn Basin, Montana
Hagen and Surdam, 1984
Kinetic Model of Tissot and Espitalie, 1975
Tissot and Espitalie, 1975
Kinetic Model of Sweeney et al., 1987
Sweeney et al., 1987