Stratigraphic implications of geochemistry of oils from Middle Magdalena Valley, Colombia

Conference · Tue Mar 01 04:00:00 EST 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6326185

Illich, H A

Seventeen oils from the Middle Magdalena Valley of Colombia were studied for the purpose of acquiring an improved view of the number and nature of hydrocarbon sources in the region. Examination of the chemistry of the oils and comparison of these data to oils from other basins lead to the conclusion that the Magdalena oils were derived from a single source or series of closely related sources. The sources for the oils are believed to be stratigraphic units deposited in marine environments. This conclusion is based mainly upon the isoprenoid, normal paraffin, and polycyclic alkane composition of the oils. A marine source virtually eliminates the possibility of the source occurring within the Tertiary section. Study of lithologic descriptions of the Cretaceous sediments stratigraphically underlying the Tertiary allows the nomination of several units that may have been the source for the oils: the La Luna, Simiti, and Paja formations. Each of these formations was deposited under anoxic marine conditions, and some of them contain enough organic debris to be described as carbonaceous. Differences in the bulk compositions of the oils are interpreted to be related to secondary alteration processes. The Middle Magdalena oils are derived from a single source or a series of closely related sources that are probably Cretaceous in age. Some of the oils have experienced secondary alteration that is believed to account for the range of bulk compositions observed in the region. The complicated source-reservoir relationships suggested by knowledge of the oil chemistry are undoubtedly contributory to protracted exploration history of the Magdalena.

• Research Organization: Sun Exploration Div., Dallas, TX
• OSTI ID: 6326185
• Report Number(s): CONF-8304200-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
CHEMISTRY
COLOMBIA
DATA ANALYSIS
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOCHEMISTRY
GEOLOGIC STRUCTURES
GEOLOGY
LATIN AMERICA
ORIGIN
PETROLEUM
PETROLEUM GEOLOGY
RESERVOIR ROCK
SEDIMENTARY BASINS
SOURCE ROCKS
SOUTH AMERICA
STRATIGRAPHY