Research On Volcanic Rock Lithofacies Of Yingcheng Formation In Xingcheng Area Of The Northern Songliao Basin

Several researches express that the distribution of volcanic reservoirs is dominated by volcanic lithofacies,so comprehensive research on volcanic rock lithofacies will be propitious to quicken the exploration and development of volcanic reservoirs.On the base of volcanic lithology classification,10 different styles of volcanic logging interpretation models in Xingcheng area are founded by utilizing conventional,FMI and density logging data,which can be determined the nature of volcanic lithology;The geologic and seismic symbol of 5 volcanic facies are demarcated by combining core,seismic and logging data, which can be determined the nature of volcanic lithofacies;The relation between effective volcanic reservoirs and lithology,lithofacies is established by contrasting the distribution of porosity, permeability, frequency and reservoirs'thickness,it is deduced that effective reservoirs mostly distribute in acidic volcanic rock included rhyolite, pore rhyolite,rhyolitic(clinkery)tuff lava,rhyolitic(clinkery)breccia lava and rhyolitic(clinkery)conglomerate lava;The favorable lithofacies exist the pyroclastic-bearing lava flow of explosive facies and the upper or mid of effusive facies;Volcanic lighofacies in Xingcheng area are characterized by small scale, bad connexity in the horizontal orientation and extremely low porosity , permeability and severe heterogeneity in the vertical orientation by coring long channel wells and arranging dense well pattern.The lithofacies distribution of three volcanic cycles in Yingcheng Formation in Xingcheng Area is predicted according as the correlation of seismic facies and lithofacies gained by the means of waveform clustering.