松辽盆地徐家围子断陷安达次洼火山岩气藏的主要特征

徐家围子断陷是由徐西、徐中和徐东3条断裂控制的复式箕状断陷，安达次洼位于该断陷北部，火山岩岩性复杂，储层发育受控于多种因素.综合地震、地质、钻井、测井、岩心、测试及岩屑、气-水的物理化学资料，对该区营城组火山岩气藏的构造、储层和成藏特征进行了系统的研究.火山岩气藏的流体分布总体上遵循重力分异原则，以上气下水为主，说明构造位置对含气性具有一定的控制作用.火山岩相带展布、各井的试气成果及测井资料表明：本区营城组气藏没有统一的气-水界面，区内预测火山岩地层连续分布，储层错叠分布，横向连通性差，含气范围覆盖全区，气藏主要受岩性和岩相控制，为构造-岩性气藏.

Main features of volcanic gas pool in the Anda Sag, Xujiaweizi Fault-Depression of Songliao Basin

The Xujiaweizi Fault-Depression was a composite half-graben controlled by three fractures, namely, the Xuxi, Xuzhong and Xudong fractures.The Anda Sag was located in the northern part of the fault-depression.The types of volcanic rocks in this area were diversified, and reservoir development was controlled by multiple factors.A synthetic research of seismic section, geology, drilling, logging, core chemical analysis, and gas-water testing was applied to study thoroughly the structure, characteristics and formation of volcanic reservoirs.The distribution of fluid of volcanic reservoir bution of upper gas and lower water followed the principle of gravity differentiation.The distri-demonstrated that the structural position controlled the accumulation of gas.In terms of information of volcanic phase, well testing and logging, the gas reservoir in Yingcheng Formation was considered without unified water-gas interface.The volcanic formation was distributed continuously, but the lateral connectivity of reservoirs was not well.Gas reservoirs of volcanic rocks in the Anda Sag should be mainly structural-lithologic reservoirs controlled by lithology and lithofacies.