【摘要】 玛湖凹陷西斜坡云质岩致密油是准噶尔盆地近年来的重要勘探领域。通过对乌夏地区风城组云质岩特征分析,对云质岩致密油发育的主控因素进行总结,认为风城组地层发育优质烃源岩,其岩性、物性以及裂缝发育程度共同决定了致密油"甜点"分布。根据基质孔隙与裂缝的配置关系,将致密油"甜点"类型分为孔隙型、裂缝型及孔隙-裂缝型。通过地震岩石物理分析和正演模拟进行地震敏感参数分析,确定"甜点"的岩性、物性、厚度及围岩特征对地震响应的影响,在此基础上选择有效的致密油"甜点"预测方法,运用地震多属性分析技术,预测云质岩分布有利区;利用波阻抗反演以及随机模拟反演技术对储层物性参数进行反演,预测孔隙发育有利区;以矿物成分脆性指数评价法和蚂蚁追踪技术,预测裂缝发育有利区。综合岩性、物性、裂缝预测成果,划分Ⅰ类、Ⅱ类和Ⅲ类"甜点"有利区,为该地区下一步致密油勘探提供依据。更多还原

【Abstract】 Dolomitic tight oil reservoir in west slope of the Mahu Sag has become an important exploration domain in the Junggar Basin in recent years.Based on characteristic analysis of the dolomitic rock of the Fengcheng Formation in Wuxia area,we summarized the controlling factors of dolomitic tight oil reservoir development,and concluded that high quality source rocks occur in the Fengcheng Formation,and the distribution of‘sweet spot’was jointly determined by lithology,porosity and fracture development.According to the association of matrix porosity and fracture,the ‘sweet spots’ were divided into porosity type,fracture type and porosity-fracture type.The influences of lithology,porosity,thickness,surrounding rock of ‘sweet spot ’to seismic responses were studied through seismic petrophysical analysis and seismic forward modeling on sensitive parameters.On this basis,effective tight oi ‘sweet spot’prediction methods were selected and seismic multi-attribute analysis technique was used to predict the distribution of favorable dolomitic rocks.The distribution of favorable porosity was predicted by using acoustic impedance inversion and stochastic simulation inversion technique.The distribution of favorable fractures was predicted by using mineral composition brittleness index evaluation method and ant tracking technology.The‘sweet spots’ of type-Ⅰ,type-Ⅱand type-Ⅲ were identified based on integration of lithology,porosity,fracture prediction results.These study results provide the basis for further tight oil exploration in the region.更多还原