LITHOLOGIC IDENTIFICATION MODE OF IGNEOUS ROCKS AND ITS APPLICATION IN THE CHANGLING FAULT DEPRESSION,SONGLIAO BASIN

Volcanic rock facies is key to analyze volcanic edifices,identify volcanic lithology and predict potential reservoir.Based on geological,seismic and drilling data from the Changling fault depression in Songliao basin,this paper probes into the formation mechanism and recognition features of explosive facies,overflow facies,volcanic sediment facies,volcanic vent facies,and extrusive facies,reveals that explosive facies and overflow facies are favorable facies belts for oil and gas concentration.A volcanic edifice lithological facies change rules is summarized according to the identification mode of igneous rocks.This paper,combined with geological setting such as deep faults and lithofacies changes,identifies many volcanic units in Cha'ganhua structure zone in eastern Changling fault depression,expands the distribution of explosive facies and overflow facies,which gives an achievement in natural gas exploration.