关键词: 吐哈盆地, 台北凹陷, 成岩演化, 次生孔隙带, 成岩期, 原生孔隙带, 隐蔽岩性油气藏

Abstract: The observation of diagenetic evolution and pore types of sedimentary rock in Taibei Sag of Tuha Basin shows that the pores of reservoir in Taibei Sag can be defined vertically into six types of the primary pore zones,the primary-induced pore zones,the induced pore zones,the reduced induced pore zones,the secondary induced pore zones and the secondary reduced induced pore zones.The sequence-stratigraphic and comparative analysis show that the distributions of different pore zones are obvious in vertical and horizontal directions.The plane distribution of the induced pore zones,as a whole,showed deep in the west and south parts and shallow in the east and north parts.The effectiveness of reservoir pores correlated to the induced pore zones was determined.The main pores are distributed mostly under the induced pore zones.According to the controlling factors of the reservoir properties,buried history of sedimentary,oil and gas migration,and structure characteristics,the new favorable areas for oil and gas prospecting were predicted,and the controlling factors for lower limit of effective pores in reservoir was analyzed.The results can provide basis for exploration of lithologic oil pool and depression of risk for the deep exploration.

Key words: Tuha Basin, Taibei Sag, diagenetic evolution, induced pore zone, primary pore zone, lithologic oil pool