松辽盆地深层天然气成藏条件与勘探方向

松辽盆地深层天然气勘探除徐家围子、长岭和英台断陷外，其他断陷的勘探效果尚不明显。依据大量的地震、野外露头、岩心观察、分析化验等资料，对松辽盆地深层断陷结构、烃源岩、火山岩储层等天然气成藏条件进行系统研究后认为：该区深层天然气分布受断陷、火山岩、断裂与不整合面控制；深层主要断陷期为沙河子期，由34个大小不一、相互独立的断陷组成断陷群，天然气在各断陷中自成含气系统，主要分布于早盛继承型断陷中；烃源岩严格分布于各断陷中，烃源岩最好的区域位于断陷中部，地震反射特征为席状平行结构，成层性、连续性好；火山岩储层形成受岩相、岩性、顶面构造、喷发旋回等控制；以次级洼陷为评价单元对断陷进行了评价，提出成藏条件好的中小型断陷具有较大勘探潜力的新认识，指出双城（莺山）、林甸等为有利的接替断陷。

Gas pooling conditions and exploration direction in deep Songliao Basin

Gas exploration has not been very successful in deep Songliao Basin, except for the Xujiaweizi, Changling and Yingtai fault depressions. Seismic data, outcrop data, core observation and laboratory test results were integrated to study the gas pooling conditions in the basin, including the architectures of the deep fault depressions, source rocks and volcanic reservoirs. The following results were obtained: The distribution of deep gas reservoirs are controlled by fault depressions, volcanic rocks, faults and unconformities. The main stage of deep fault depressions was during the deposition of the Shahezi Formation, with 34 mutually independent clustering fault depressions of different sizes. Each depression has its own independent petroleum system and gas is mainly distributed in the inherited fault depressions. The source rocks are completely distributed in each fault depression, in the central part of which there are best source rocks featured by sheet like parallel reflection configuration, good stratification and continuity from the seismic reflection. The development of volcanic reservoirs is controlled by lithofacies, lithology, top structures and eruption cycles. The depressions were evaluated with sub depressions as appraisal unit. The medium to small fault depressions with good pooling conditions have relatively large exploration potential, and Shuangcheng (Yingshan) and Lindian depressions are believed to be favorable for future exploration.