Lithofacies and reservoir characteristics of volcanic rocks in Wangshen 1 block in northern Songliao Basin

The volcanic lithofacies and reservoir characteristics in Wangshen 1 block in northern Songliao Basin are analyzed. The volcanic lithofacies of Yingcheng Formation in Wangshen 1 block can be divided into volcanic vent facies, eruptive facies, overflow facies and volcanic sedimentary facies. The main lithofacies are eruptive facies and overflow facies. Based on this division, the volcanic eruption model is established. There are six types of volcanic reservoir space in this area. The volcanic reservoir is mainly controlled by lithology, lithofacies and postdiagenesis. The favorable reservoir mainly distributed in the band of autoclastic lava in the upper subfacies of effusion and in the common volcanic breccia in eruption air fall subfacies. Condensation, effusion of residual liquid,dissolution and tectogenesis are the main advantageous diagenesis for the formation and conservation of pore and seam. The volcanic reservoir in this area is evaluated, and it can be mainlydivided intotypeⅡ and type Ⅲ reservoir.