Petroleum exploration of shallow marine deposit Carboniferous volcanic tuff reservoir in the western margin of Junggar Basin
摘要
In 2011,petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir realized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pai 61 well,with 855.7 ~ 949.6 m section,in the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa· s (50 °C). The marine deposit of Carboniferous are deep oil source rocks and high-quality reservoir. Magma volcanic activity provides the basis for volcanic reservoir development and distribution. The weathering crust and secondary cracks developed volcanic tuff by strong rock weathering and dissolution of organic acids which has become top quality reservoir. Deep Permian oilgas migrated and accumulated to high parts along HongChe fault belt and stratigraphic unconformity stripping. Permian and Triassic volcanic rocks or dense mudstone sedimentary cover as a regional seal for the late Carboniferous oil-gas to save critically. The seismic pre-stack time migration processing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obvious. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.