Relationship between diagenesis and reservoir quality in sandstones of the Garn Formation, Haltenbanken, Mid-Norwegian Continental Shelf

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5894987

Ehrenberg, S N ^[1]

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1. Geologisk Lab., Stavanger (Norway)

A quantitative model is proposed for the dependence of porosity and permeability on diagenesis in subarkosic arenites of the Middle Jurassic Garn Formation. Porosity variation is controlled by the combined effects of compaction and quartz cementation. In general, more porosity has been lost by compaction than by quartz cementation, but compactional porosity loss appears to have occurred relatively early in the burial history (before burial below 2 km below the sea floor). Thus, progressive reduction of the total porosity with increasing burial below 2 km results mainly from quartz cementation. Permeability is a function of the abundance of intergranular macroporosity, which is interpreted to be a measure of effective porosity. At depths less than 3.5 km below the sea floor, intergranular macroporosity generally comprises more than 50% of the total porosity, but at greater depth, as total porosity decreases below about 16%, the ratio of effective to ineffective porosity drops below one. This depth corresponds to the onset of extensive illitization and grain dissolution, which results in major reorganization of the pore system. Generation of secondary porosity by feldspar dissolution appears not to have been beneficial to reservoir quality in the Garn Formation, but it is regarded as an intrinsic part of the overall process of porosity destruction with increasing diagenesis.

• OSTI ID: 5894987
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 74:10; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
CONTINENTAL MARGIN
CONTINENTAL SHELF
CRYSTAL STRUCTURE
DEVELOPED COUNTRIES
DIAGENESIS
EUROPE
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC MODELS
JURASSIC PERIOD
MESOZOIC ERA
MICROSTRUCTURE
MINERAL RESOURCES
NORWAY
PERMEABILITY
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SCANDINAVIA
SEDIMENTARY ROCKS