Silurian shale origin for light oil, condensate, and gas in Algeria and the Middle East

Conference · Mon Jan 01 00:00:00 EST 1996 · AAPG Bulletin

OSTI ID:6582129

Zumberge, J E ^[1]

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1. GeoMark Research Inc., Houston, TX (United States)

Two of the largest gas fields in the world, Hasi R'Mel, Algeria and North Dome, Qatar, also contain substantial condensate and light oil reserves. Gas to source rock geochemical correlation is difficult due to the paucity of molecular parameters in the former although stable isotope composition is invaluable. However, by correlating source rocks with light oils and condensates associated with gas production using traditional geochemical parameters such as biomarkers and isotopes, a better understanding of the origin of the gas is achieved. Much of the crude oil in the Ghadames/Illizi Basins of Algeria has long been thought to have been generated from Silurian shales. New light oil discoveries in Saudi Arabia have also been shown to originate in basal euxinic Silurian shales. Key sterane and terpane biomarkers as well as the stable carbon isotopic compositions of the C15+ saturate and aromatic hydrocarbon fractions allow for the typing of Silurian-sourced, thermally mature light oils in Algeria and the Middle East. Even though biomarkers are often absent due to advanced thermal maturity, condensates can be correlated to the light oils using (1) carbon isotopes of the residual heavy hydrocarbon fractions, (2) light hydrocarbon distributions (e.g., C7 composition), and (3) compound specific carbon isotopic composition of the light hydrocarbons. The carbon isotopes of the C2-C4 gas components ran then be compared to the associated condensate and light oil isotopic composition.

• OSTI ID: 6582129
• Report Number(s): CONF-960527-; CODEN: AABUD2
• Journal Information: AAPG Bulletin, Vol. 5; Conference: Annual convention of the American Association of Petroleum Geologists, Inc. and the Society for Sedimentary Geology: global exploration and geotechnology, San Diego, CA (United States), 19-22 May 1996; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
02 PETROLEUM
58 GEOSCIENCES
ALGERIA
GAS CONDENSATE FIELDS
NATURAL GAS FIELDS
GEOCHEMISTRY
QATAR
GAS CONDENSATES
PETROLEUM DEPOSITS
SILURIAN PERIOD
SOURCE ROCKS
AFRICA
ARAB COUNTRIES
ASIA
CHEMISTRY
CONDENSATES
DEVELOPING COUNTRIES
FLUIDS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
LIQUIDS
MIDDLE EAST
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NATURAL GAS LIQUIDS
PALEOZOIC ERA
RESOURCES
030200* - Natural Gas- Reserves
Geology
& Exploration
020200 - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences