摘要
The reservoirs discovered in the Turpan Depression are mainly distributed in the Middle Jurassic, some distributed in the Upper Jurassic, Cretaceous and Tertiary. The characteristics of the mudstone overpressure are studied to reveal the relationship between reservoir distribution and mudstone overpressure. There are several overpressure mudstone cap-rocks in the depression, of which the most steady and the best one is in the Middle Jurassic Qiketai Formation. The distribution of reservoirs in the Jurassic and above sequences is controlled dominantly by mudstone overpressure. In the regions without mudstone overpressure, reservoirs are often destroyed because of frequent fault activities. Reservoirs have different dependence on the overpressure mudstone sealing. Overpressure mudstone seals oil reservoirs indirectly, while it seals gas reservoirs and gas-cap reservoirs directly. For the areas without rock salt or gypsum in the multi-cycle basins in West China, mudstone overpressure will play an important role in the hydrocarbon accumulation and reservoir preservation.