Generation and accumulation of hydrocarbons in the Gippsland basin, southeastern Australia

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5497821

Yin, P

Clastic diagenesis of the reservoir rocks and organic geochemistry of the source rocks were studied in the offshore Central Deep of the Gippsland Basin. Pyrolysis, elemental analysis, and vitrinite reflectance data documented that the brown coal and dark shale of the Late Cretaceous-Eocene Latrobe Group served as the source rocks in the basin. The source rocks contain Type III kerogen with high organic carbon content (5 to 60%) and a genetic potential of 10 to 100 kg of hydrocarbon per ton of source rock. Hydrogen indices indicate that the Latrobe source rocks are both gas- and oil-prone. The zone of major hydrocarbon generation is located in the Upper Cretaceous; the Tertiary source rocks are still immature. Nuclear magnetic resonance, chemical extraction, and oxidative degradation analysis demonstrate that abundant organic acids have been released from the source rocks prior to major hydrocarbon generation. This study suggests that the porosity in the Latrobe sandstones has been modified by mechanical compaction. Dolomite cement distributed around paleo-channels was probably precipitated by the mixing of fresh water with sea water. Dissolution of the framework grains and cement, occurring predominantly in the temperature interval between 80 and 120 C, is believed to be caused by water-soluble organic acids. Burial history reconstructions, thermal modeling, and the calculation of transformation ratio suggest that the generation of hydrocarbons from the Latrobe source rocks started 90 Ma ago and is still occurring. A knowledge of the timing of hydrocarbon generation, porosity modification, hydrocarbon seal formation, and structure evolution is essential to the further exploration for hydrocarbon in the Gippsland Basin.

• Research Organization: Wyoming Univ., Laramie, WY (USA)
• OSTI ID: 5497821
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
011000 -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
04 OIL SHALES AND TAR SANDS
040201 -- Oil Shales & Tar Sands-- Site Geology-- (-1989)
ABUNDANCE
ALKALINE EARTH METAL COMPOUNDS
AUSTRALASIA
AUSTRALIA
BITUMINOUS MATERIALS
BLACK SHALES
BROWN COAL
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE MINERALS
CARBONATES
CHATTANOOGA FORMATION
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COAL
DIAGENESIS
DOLOMITE
ENERGY SOURCES
EXPLORATION
EXTRACTION
FOSSIL FUELS
FUELS
GEOCHEMICAL SURVEYS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC MODELS
KEROGEN
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MAGNETIC RESONANCE
MATERIALS
MINERAL RESOURCES
MINERALS
NATURAL GAS DEPOSITS
NUCLEAR MAGNETIC RESONANCE
OFFSHORE SITES
OIL SHALES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC MATTER
OXIDATION
OXYGEN COMPOUNDS
PENNSYLVANIAN PERIOD
PETROLEUM DEPOSITS
POROSITY
RESONANCE
RESOURCE POTENTIAL
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SEPARATION PROCESSES
SOURCE ROCKS
SURVEYS