The oil generation maturity limits for a type I kerogen as determined by hydrous pyrolysis

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7078079

Schiefelbein, C ^[1]; Ho, T ^[2]

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1. Core Labs., Carrollton, TX (United States)
2. Conoco Inc., Ponca City, OK (United States)

Changes in the physical properties (measured in terms of vitrinite reflectance, elemental analysis, and C-13 nuclear magnetic resonance) of an immature coal (0.46% R{sub o}) from Craig County, Colorado, that was thermally altered using hydrous pyrolysis were used to establish a correspondence between hydrous pyrolysis time/temperature reaction conditions and relative maturity (expressed in terms of vitrinite reflectance). This correspondence was used to determine the oil generation maturity limits for an immature hydrogen-rich (Type I fluorescing amorphous oil-prone kerogen) source rock from an offshore Congo well that was thermally altered using the same reaction conditions as applied to the immature coal. The resulting changes in the physical properties of the altered source rock, measured in terms of decreasing reactive carbon content (from Rock-Eval pyrolysis), were used to construct a hydrocarbon yield curve from which the relative maturity associated with the onset, main phase, and peak of oil generation was determined. Results, substantiated by anhydrous pyrolysis techniques, indicate that the source rock from Congo has a late onset of appreciable ({gt}10% transformation) oil generation (0.9% R{sub o} {plus minus} 0.1%), generates maximum quantities of oil from about 1.1 to 1.3% R{sub o}, and reaches the end (or peak) of the primary oil generating window at approximately 1.4% R{sub o} ({plus minus}0.1%) when secondary cracking reactions become important. However, the bottom of the oil window can be extended to about 1.6% R{sub o} because the heavy molecular weight degradation by-products (asphaltenes) that are not efficiently expelled from source rocks continue to degrade into progressively lower molecular weight hydrocarbons.

• OSTI ID: 7078079
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
01 COAL, LIGNITE, AND PEAT
COLORADO
PETROLEUM DEPOSITS
KEROGEN
MATURATION
SOURCE ROCKS
ZAIRE REPUBLIC
COAL
PETROLEUM
PYROLYSIS
REFLECTIVITY
TEMPERATURE EFFECTS
THERMAL DEGRADATION
VITRINITE
AFRICA
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DECOMPOSITION
DEVELOPED COUNTRIES
DEVELOPING COUNTRIES
ENERGY SOURCES
FEDERAL REGION VIII
FOSSIL FUELS
FUELS
GEOLOGIC DEPOSITS
MACERALS
MATERIALS
MATTER
MINERAL RESOURCES
NORTH AMERICA
OPTICAL PROPERTIES
ORGANIC MATTER
PHYSICAL PROPERTIES
RESOURCES
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
USA
023000* - Petroleum- Properties & Composition
010600 - Coal
Lignite
& Peat- Properties & Composition
020200 - Petroleum- Reserves
Geology
& Exploration