New prospects in Cambrian platform orthoquartzites in Poland

Conference · Thu Aug 01 00:00:00 EDT 1991 · Geobyte; (United States)

OSTI ID:5680788

Labecki, J; Weil, W ^[1]; Schleicher, M; Kulke, H; Koester, J ^[2]

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1. Polish Oil and Gas Co., Warsaw (Poland)
2. Univ. of Clausthal, Clausthal-Zellerfeld (West Germany)

Middle Cambrian orthoquartzites produce oil in two small fields northwest of Gdansk, Poland; few developed offshore discoveries exist in the southeastern Baltic Sea. This joint Polish-German study on these poorly porous sandstones is aimed at delineating areas of better reservoir quality development and thus of future prospects. In the Polish part of the East European platform, Cambrian deposits exist in four geologic provinces (Lublin slope, Podiassle depression, Warsaw synclinorium, Baltic syneclise). In these areas, the Cambrian, which in part is more than 500 m thick, has been buried to depths between 300 and approximately 6000 m. The Middle Cambrian orthoquartzitic sandstones represent a shallow-marine sequences with interbedded claystones. Their porosities range form 2 to 8%, and oil production is improved by natural fractures. A major source rock for the oil accumulations is represented by Upper Cambrian black shales (TOC values, 3-13%; thickness approximately 1-10 m in northern onshore Baltic syneclise, up to 50 m in southern Scania, Sweden). The Middle Cambrian shales show low TOC contents (average, 0.3-0.6%) and a thickness of approximately 200 m. Despite their low organic content, they also could have been contributed to the reservoired oil because both black shales show maturities within the oil window and both contain an oil-prone algal kerogen. Therefore, in the northeast Polish oil province the restricted pore volume of the orthoquartzites and not the source rock parameters represents the major limiting factor for larger oil accumulations. Future prospects will be difficult to predict because the occurrence of traps might be much more controlled by diagenesis than by (tectonic) structures.

• OSTI ID: 5680788
• Report Number(s): CONF-910978-; CODEN: GEOBE
• Journal Information: Geobyte; (United States), Vol. 75:8; Conference: International conference and exhibition of the American Association of Petroleum Geologists (AAPG): the way ahead-hydrocarbons for the 1990s, London (United Kingdom), 29 Sep - 3 Oct 1991; ISSN 0885-6362
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
NATURAL GAS DEPOSITS
PETROLEUM GEOLOGY
STRATIGRAPHY
PETROLEUM DEPOSITS
POLAND
SOURCE ROCKS
GEOCHEMISTRY
BLACK SHALES
CAMBRIAN PERIOD
CEMENTS
DEPOSITION
DIAGENESIS
GEOLOGIC HISTORY
POROSITY
RESERVOIR ROCK
SANDSTONES
BUILDING MATERIALS
CHEMISTRY
DEVELOPING COUNTRIES
EUROPE
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
MATERIALS
MINERAL RESOURCES
PALEOZOIC ERA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SHALES
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration