Precambrian Reservoirs Sealed by Western Carpathian Nappes, Southeast Slope of the Bohemian Massif, Moravia, Czechoslovakia

KREJCI, J. J., Moravian Petroleum Company, Hodonin, Czechoslovakia

The West Carpathian overthrust in Moravia, Czechoslovakia, overlies Proterozoic crystalline basement productive from buried topographic ridges and hills. The Neogene thrust belt forms the seal for oil and gas trapped in the Precambrian crystalline rocks which have been disaggregated by joints, fractures, and weathering. The reservoir rocks include granite, granodiorite, and quartz diorite.

Five oil and gas fields have been discovered in this unusual setting. Zdanice-Krystalinikum field is the largest of this type of field in Czechoslovakia (its cumulative production is 66,000 tons of oil), and the ultimate potential is unknown as development is still in process. Three separate pools have been discovered in this field, with differing oil/water contacts and sometimes different oil gravities. These pools appear to be separated by fault zones that have sealed and become impermeable. Other Precambrian reservoir production in Moravia includes East and West Kostelany, West Zdanice, and Korycany fields.

Zdanice-Krystalinikum field was discovered using refraction and reflection seismic lines and correlations with previously drilled dry holes which had encouraging shows.

AAPG Search and Discovery Article #91007© 1991 AAPG International Conference, London, England, September 29-October 2, 1991 (2009)