关键词: 盐岩, 生物礁, 油气分布规律, 勘探潜力, 滨里海盆地

Abstract: Precaspian Basin in CentralAsia, rich in oil and gas resources, is noted for the Kungurian significant thickness of salt bed. The structural evolution of Precaspian Basin mainly experienced three stages: inception of rifting, passive continental margin, and compression of rifting phases. The start of exploration in the Precaspian Basin dates back to the late 19th century, and the whole courses can be divided into two parts including early post-salt exploration and late pre-salt exploration. With large number, wide distribution and small scale, the quantity of post-salt reservoirs accounts for over 80% of the total. But due to good development of carbonate platform and reef complex, nine giant oil-gas fields (total recoverable Mmboe ≥ 500) have been found in the pre-salt reservoirs, where there are plenty of other large oil-gas fields. The most effective source rocks are the Middle Devonian-Middle Carboniferous relatively thin pelagic calcareous, siliceous, and argillaceous basinal facies rich in organic matter which accumulated on the slopes of the starved central deep. The Carboniferous bioherm and bioclastic limestone are the most favorable reservoirs. Besides, the most important regional seal is the Lower Permian Kungurian salt sequence. Furthermore, there are a great many Stratigraphic-Structural traps along Precaspian Basin?s verges. Focus of discovering giant oil-gas fields, hydrocarbon exploration orientation is based on òPre-salt first considering Post-saltó, and priority area is Astrakhan-Aktjubinsk Uplift Zone.

Key words: salt rock, organic reef, oil-gas distribution law, exploration potential, Precaspian Basin