Aquitaine Oil and Gas Bearing Basin

AQUITAINE OIL AND GAS BEARING BASIN is located in the lowlands of the same name in the south of France and in the water area of the Bay of Biscay. The area is 152 thousand square kilometres. The first gas field (Saint-Marcet) has been discovered in 1939; 7 gas fields and 14 oil fields have been discovered till 1982: the Lacq is the largest gas field, the Parentis is the largest oil field (with initial reserves of 30 million tonnes) (see the map).

AQUITAINE OIL AND GAS BEARING BASINAQUITAINE OIL AND GAS BEARING BASIN

  • The fields are numbered
  • 1 Parentis
  • 2 Lacq
  • 3 Saint-Marcet
  • 4 Cazaux
  • 5 Mimizan
  • 6 Vic-Bilh
  • L.A.Faingersh has developed the special content

The industrial reserves (1980) of all the fields of the gas are 80 billion cubic metres, of the oil are 4.5 million tonnes. It has been formed on the deeply sunk slope of the Epihercynian Western European platform, which transitions into the Pyrenean foreland basin at the south. It is limited at the north and east by the Caledonian structures of the Armorican and Central massifs, at the south by the thrust of the Pyrenees and their underwater extension. The western boundary coincides with the underwater Northern-Gascon ridge.

The sedimentary cover is represented by the four complexes: Jurassic-Neocomian carbonatic, Aptian-Albian-Cenomanian terrigenous-carbonatic, Upper Cretaceous carbonatic-terrigenous, and Cenozoic terrigenous. The greatest thickness of the cover is 10 kilometres. The reservoirs are confined to the anticlinal folds, which are sometimes broken by the ruptures. The limestones of the Jurassic-Neocomian and Aptian are oil and gas bearing. The depth of the laying of the productive horizons is 600-5300 metres. The density of the oils is 818-986 kilograms per cubic metre. The gases distinguish themselves by the high contents of the hydrogen sulfide (up 15.23%). In 1980, there have been extracted in the basin the 1.9 million tonnes of the oil with condensate, and 7.5 billion cubic metres of gas; the cumulative extraction is 40.8 million tonnes of oil, and 137 billion cubic metres of gas. There operate there the trunk gas pipeline Lacq-Paris and the oil pipeline Parentis-Bordeaux. The main centre of the extraction is the Pau city.