徐家围子汪深1区块火山岩岩相特征及识别标志研究

火山岩储层岩性类型多样,岩相变化快,因而对火山岩储层评价和预测难度较大.以松辽盆地北部汪深1区块为例,对该区火山岩岩性岩相特征及识别标志进行了深入分析,探讨火山岩岩相类型与储层发育特征的关系.研究表明汪深1区块营城组火山岩分为火山通道相、爆发相、溢流相、火山沉积相等4种岩相类型,以爆发相和溢流相为主,有利的储层主要分布在喷溢相上部亚相角砾状熔岩以及爆发相空落亚相的普通火山角砾岩带中.

Characteristics and recognition marks of the volcanic lithofacies in Wangshen 1 block of Xujiaweizi area in the north of Songliao Basin

Since Wangshen 1 block is explored in 1994,its predicted geological reserves of natural gas is 249.56×108 m3,and of this,the geological reserves of natural gas in the volcanic rock reservoir of Yingcheng Formation is 190.7×108 m3,which shows the good exploration and development prospects of Wangjiatun volcanic reservoir.But the variety of the litholotic types and the quick change of the lithofacies of the volcanic reservoir make the evaluation and prediction of the reservoir more difficult.Taking the Wangshen 1 block as an example,the lithofacies characteristics of the volcanic rock in this area and their recognition marks are analyzed,and relationship between the types of the volcanic lithofacies and the characteristics of the reservoir development is discussed.It is shown that,there are four lithofacies types of the volcanic rock of Wangshen 1 block:volcanic channel facies,eruption facies,effusive facies and volcanic sedimentary facies.The main lithofacies are eruption facies and effusive facies.The favorable reservoirs mainly distribute in the autoclastic lava band in the upper subfacies of the effusive facies and the common volcanic breccia band in the air fall subfacies of the eruption facies.