Hydrocarbon Discoveries in Paleozoic Solimoes Basin, Upper Amazon Region, Brazil

Neto Apoluceno, Amaro Ferreira, Kaoru Tsubone

The Solimoes basin, previously known as Upper Amazon basin, is located in northern Brazil and has a prospectable area of more than 300,000 km². The Purus arch, a regional positive feature, separates this basin from the Amazonas basin. As far as the basin geology is concerned, the Solimoes basin is strikingly different from its neighboring basin due to certain structural and stratigraphic peculiarities. Between the Late Jurassic and Early Cretaceous the basin was affected by regional compressional tectonics that generated a series of northeast-southwest-oriented trends. The exploration play in the basin is classic wrench tectonics--elongated dome structures on upthrown blocks of en echelon reverse faults. Despite the problems of working in a tropical forest, Pet obras has made a systematic exploration campaign in the basin since the early 1970s. This effort was compensated by the discovery of two important hydrocarbon-bearing areas: Jurua gas province in 1978 and the Urucu River oil, gas, and condensate province in 1986. The latter, whose commercial oil production was initiated in July 1988, is considered an important marker in the petroleum exploration history of Brazil, particularly with respect to the Paleozoic basins, which total more than 3 million km² of the country's territory.

AAPG Search and Discovery Article #91022©1989 AAPG Annual Convention, April 23-26, 1989, San Antonio, Texas.