准西海相浅层石炭系火山凝灰岩油气发现的意义

Petroleum exploration of marine deposit,shallow,Carboniferous and volcanic tuff reservoir in the western margin of Junggar Basin

2011年,准西海相浅层石炭系火山凝灰岩油气勘探取得了突破,见到了良好的油气显示,特别是排61井在855.7～949.6 m井段,常规试油获得日产6 t的工业油流,50℃地面脱气原油黏度为390 mPa.s。排61地区石炭系稳定的海相沉积层既是深部油源岩,又是优质储集层。岩浆活动提供了火山岩储层发育和分布的基础。火山凝灰岩经受了强烈的风化作用和有机酸溶蚀作用,风化壳及次生裂缝很发育,成为优质储层。深部二叠系油气沿红车断裂带和地层超剥带不整合面向高部位运聚成藏。二叠系和三叠系致密的火山岩或泥岩沉积覆盖作为区域性盖层对石炭系油气后期保存至关重要。针对石炭系储层成像较差的难题发展了地震叠前时间偏移处理技术,火山岩地震和测井响应特征比较明显,应用成像测井和核磁共振技术实现了裂缝的定性识别和定量描述。

In 2011, petroleum exploration of marine deposit,shallow,Carboniferous,and volcanic tuff res- ervoir realized breakthroughs at Chepaizi slope in the western margin of Junggar Basin, Pal 61 well,with 855.7 ~ 949.6 m section, and the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa ·s （50℃ ）. The marine sediments of Carboniferous are both deep oil source rocks and high-quality reser- voir. 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 and became top quality reservoir. Deep Permian oil-gas migrated and accumulated to high parts along Hong-Che 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 critical. The seismic pre-stack time migration pro- cessing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obviously. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.