Petroleum Generation

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Petroleum Generation
Petroleum Geology Class 745 Spring 2002
Istvan Csato University of South
Carolina Department of Geological Sciences
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I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
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Sequence Stratigraphy
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Controls on total organic matter

• Productivity
• Grain size
• Sedimentation rate
• Oxidation/Reduction

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Preservation of Organic Matter
Demaison and Moore, 1980
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Conversion of Organic Matter

• biopolymers
• bitumen
• biomarkers

Barker, 1996
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I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
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Conversion of Kerogen
Organic matter 1

• Kerogen 90
• Bitumen 10

Barker, 1996
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Kerogen Evolution Paths
Tissot et al., 1974
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Variation of the HC/TOC, Los Angeles and Ventura
Basins
Philippi, 1965
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Depths and Temperatures for Onset of Oil
Generation
Tissot et al., 1975
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General Scheme for Hydrocarbon Formation
Tissot et al., 1974
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I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
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Questions for exploration geologist

• Does the the rock have sufficient organic matter?
• Is the organic matter capable of generating?
• Has this organic matter generated petroleum?
• Has the generated petroleum migrated out?
• Is the rock oil-prone or gas-prone?

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Quantity of Organic Matter TOC must be greater
than 0.5
Type of Organic Matter
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Maturity
Thermal Alteration Index, Paris Basin
Correia, 1971
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Maturity
Kerogen Maturation Profile, Louisiana Gulf Coast
Vitrinite woody, Type III kerogen
Barker, 1996
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Maturity
Vitrinite Reflectance Data
Dow and OConnor, 1982
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Maturity
Vitrinite Reflectance Profile, Elmsworth Field,
Canada
Welte et al., 1984
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Disturbing of Vitrinite Reflectance
Barker, 1996
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Elemental Data For Kerogen
Peters, 1986
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Pyrolysis
Increase of S1 with Depth
S2
S1
Tmax
Barker, 1996
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Pyrolysis
Yield of Hydrocarbons with Increasing Temperature
S2
S1
S2/TOC HI S3/TOC OI
S1
S2
Tmax
Barker, 1974
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Changes in TR and Tmax
Espitalie et al., 1977
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HI versus OI
Peters, 1986
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Evaluation of Geochemical Parameters
Peters, 1986
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I. Organic Matter
II. Petroleum Generation
III. Source Rock Evaluation
IV. Thermal Maturation Models
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Kinetics of Chemical Reactions
KER BIT RESIDUE
At t0 KER Vo, BIT0 At tgt0 KERVo-Vt,
BITVt dV/dt k(Vo-Vt) kAe-E/RT
Arrhenius equation
R Gas constant (0.008314 KJ/mol0K) Tabsolute
temperature Eactivation energy Afrequency factor
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Activation Energy
Barker, 1996
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Bond Energies
March, 1985
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Increasing Reaction Rate with Temperature
Barker, 1996
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Bitumen Release Curves with Different Activation
Energies
Barker, 1996
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Bitumen Release Curves with Different Frequency
Factors
Barker, 1996
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Increase in Reaction Rate
Barker, 1996
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Bitumen Release Curves for 8 Parallel Reactions
Juntgen and Klein, 1975
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Distribution of Activation Energies, Paris Basin
Tissot et al., 1987
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Temperature Factors used by Lopatin
Dmaturity (Dti)(rni)
TTI (Time-Temperature Index)
Barker, 1996
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Burial History Plot
Barker, 1996
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Calculated TTI
Barker, 1996
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Calibration of TTI
Waples, 1980
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Time-Temperature Reconstruction, Big Horn Basin,
Montana
Hagen and Surdam, 1984
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Kinetic Model of Tissot and Espitalie, 1975
Tissot and Espitalie, 1975
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Kinetic Model of Sweeney et al., 1987
Sweeney et al., 1987