Baltic petroleum-and-gas-bearing province

BALTIC PETROLEUM-AND-GAS-BEARING PROVINCE (RU: Балтийская нефтегазоносная область) is located at the west of the USSR (Lithuanian SSR, Latvian SSR, Kaliningrad province of the Russian Federation) and at the north-east of Poland, it covers also the water area of the Central and Southern Baltic sea (the coastal shelves of the USSR, Poland, and Sweden). The area is more than 170 thousand square kilometres. Of these, the water area is approximately 70 thousand square kilometres (see the map). The systematic exploration is performed since the 1946, the first petroleum field has been discovered within the limits of the USSR during the 1968, within Poland during the 1971. By the 1981, there have been identified within the limits of the Baltic petroleum-and-gas-bearing province the 27 petroleum fields; the extraction of petroleum is performed since the 1975.(Map) BALTIC PETROLEUM-AND-GAS-BEARING PROVINCE

Baltic petroleum-and-gas-bearing province is situated within the forest zone. There is available within its limits the well developed network of the automobile roads and railways, there is performed the marine and river navigation. The petroleum is transported by the railways. The centre of the extraction within the USSR is the Chernyakhovsk city, within Poland the Żarnowiec city. Baltic petroleum-and-gas-bearing province is confined to the Baltic syneclise of the East European tectonic plate. The basement of the syneclise is Archean - Middle Proterozoic, heterogeneous. The cover of the tectonic plate is represented by the complexes of the terrigenous, carbonatic and halogenous, continental and marine depositions of the Vendian - Lower Cambrian, Middle Cambrian - Lower Devonian, Middle Devonian - Lower Carboniferous, Upper Permian - Mesozoic-Cenozoic. There is prominent between the basement and the bottom complexes of the cover the series of the large depressions, which are bounded by the protrusions and elongated mounds. The thickness of the sedimentary cover of the Baltic petroleum-and-gas-bearing province is 6 kilometres. There are developed along the disjunctive dislocations within the sedimentary cover the elongated mounds, which are complicated by the local uplifts (with the sizes of 13-15 square kilometres and the amplitude of 30-100 metres). There are productive the depositions of the Middle Cambrian at the depth of 1.1-2.7 kilometres. The petroleum and gas manifestations have been identified also within the depositions of the Ordovician, Silurian, Devonian, and Permian. The reservoirs of petroleum are tabular vaulted and tectonically screened. The working yields of the petroleum drilled wells are average. There is characteristic the variability of the collecting properties of the rocks of the layer. The petroleums are low-sulfur, low-tar, with low content of paraffin wax, under-saturated with gas, the density is 810-860 kilograms per cubic metre.