莺山凹陷营城组火山岩储层特征及成因

CHARACTERISTICS AND ORIGINS OF YINGCHENG FORMATION VOLCANIC RESERVOIRS IN YINGSHAN SAG

莺山凹陷火山岩资源潜力大,是松辽盆地深层天然气勘探重要接替领域.但由于莺山凹陷营城组火山岩储层致密,储层分布规律不清楚,制约了勘探部署工作.针对勘探难点,对比分析了徐家围子断陷、莺山凹陷的火山岩储层特征,并着重探讨了莺山凹陷火山岩储集空间演化规律和主控因素.研究认为：莺山凹陷火山岩储集空间类型以溶蚀孔隙、裂缝为主,为溶孔（缝）—构造缝—冷凝收缩缝组合类型,水下喷发造成了火山岩原生孔隙不发育,营城组沉积后形成的2期构造裂缝为储层的溶蚀改造提供了通道,登娄库组沉积后期的酸性流体的注入对储层进行了溶蚀改造。

There was great resources potentiality for the volcanic rocks in Yingshan Sag,therefore they are the important gas-exploration replacing field in the deep zone of Songliao Basin.However,the volcanic reservoirs in Yingcheng Formation are rather tight and their distribution laws are indistinct,so the exploration deploy is limited.Countering the above exploration difficulties,and moreover contrasting and analyzing the characteristics of the volcanic reservoirs in Xujiaweizi Fault Depression and Yingshan Sag,the accumulation space （AS） evolution laws and their controlling factors are explored emphatically in the volcanic rocks of the sag.The researches show that for the AS types,the above rocks take the dissolved pores and fractures as the main forms,the combined type is the dissolved holes （fracture） ＋ structure fractures ＋ condensation shrinkage fractures,the reason of the undeveloped primary pores is the subaquatic eruption,the two-stage structure fractures which are formed after Yingcheng Formation deposition offer the passageways for the reservoir corrosion and reformation,the filling of acidic fluid brings the corrosion and reconstruction of the reservoirs after Denglouku Formation deposition.