松辽盆地长岭断陷火山岩储层特征及有效储层分布规律

火山岩油气藏是松辽盆地重要的勘探对象，为定量分析火山喷发旋回、岩性、岩相与有效储层分布的关系，基于该盆地长岭断陷66口钻井地质与测井资料、1 495 km²三维地震资料、546套实测物性及试气产能等资料，并在19 384 m火山岩井段岩性校正的基础上，划分出火山喷发旋回和火山岩相及亚相，建立起岩性、岩相、旋回与储层物性、含油气情况之间的关系，分析了火山岩储层特征及有效储层的分布规律。结果表明：①该区共发育3段10个火山喷发旋回，有效储层集中发育在火山喷发序列的顶部旋回，其中营城组一段、三段的顶部旋回（旋回三）储集性能最好；②该区主要发育11种火山岩石类型，其中流纹岩、流纹质凝灰岩、流纹质凝灰熔岩和流纹质火山角砾岩为有效储层的优势岩性；③研究区主要发育4种火山岩相11种亚相，其中喷溢相上部亚相和爆发相热碎屑流亚相为有效储层的优势岩相；④火山岩储层物性条件与其有效储层发育程度有着显著的对应关系，储层物性控制了有效储层的分布，并且在物性特征中孔隙度较之于渗透率而言，对有效储层的形成具有更明显的影响。结论认为，该区深层火山岩勘探具有良好的前景。

Characteristics of volcanic reservoirs and distribution rules of effective reservoirs in the Changling fault depression,Songliao Basin

〗In the Songliao Basin, volcanic oil and gas reservoirs are important exploration domains. Based on drilling, logging, and 3D seismic (1 495 km2) data, 546 sets of measured physical properties and gas testing productivity of 66 wells in the Changling fault depression, Songliao Basin, eruptive cycles and sub-lithofacies were distinguished after lithologic correction of 19 384 m volcanic well interval, so that quantitative analysis was conducted on the relation between the eruptive cycles, lithologies and lithofacies and the distribution of effective reservoirs. After the relationship was established between lithologies/lithofacies/cycles and reservoir physical properties/oil and gas bearing situations, an analysis was conducted on the characteristics of volcanic reservoirs and the distribution rules of effective reservoirs. It is indicated that 10 eruptive cycles of 3 sections are totally developed in this area, and the effective reservoirs are mainly distributed at the top cycles of eruptive sequences, with those of the 1^st and 3^rd Members of Yingcheng Formations presenting the best reservoir properties. In this area, there are mainly 11 types of volcanic rocks, among which rhyolite, rhyolitic tuff, rhyolitic tuffolava and rhyolitic volcanic breccia are the dominant lithologies of effective reservoirs. In the target area are mainly developed 4 volcanic lithofacies (11 sub-lithofacies), among which upper sub-lithofacies of effusive facies and thermal clastic sub-lithofacies of explosion lithofacies are predominant in effective reservoirs. There is an obvious corresponding relationship between the physical properties of volcanic reservoirs and the development degree of effective reservoirs. The distribution of effective reservoirs is controlled by reservoir physical properties, and the formation of effective reservoirs is influenced more by porosity than by permeability. It is concluded that deep volcanic gas exploration presents a good prospect in this area.