Logging Response Characteristics of Subaqueous Eruptive Volcanic Facies of Huoshiling Formation in Chaganhua Subdepression,Changling Fault Depression
There are subaqueous eruptive volcanic rocks in Huoshiling Formation of Chaganhua subdepression,Songliao basin,which are divided into two types of lithofacies and four types of subfacies.It is difficult to identify the subaqueous eruptive volcanic facies in actual production when there are few well cores.Taken the subaqueous eruptive volcanic facies of Chaganhua area as the research object,the logging characteristics of four subfacies of two types of lithofacies are analyzed and summarized in this paper:The undeveloped section of volcanic ash ball of the gas-carried subaqueous pyroclastic flow subtacies is high natural gamma and high resistivity,the curve is in the shape of medium-high amplitude finger,and the imaging logging shows high resistivity bright color.The developed section of volcanic ash ball is low natural gamma and low resistivity,the curve is flat with low amplitude,and the imaging logging shows low resistivity dark color.The water-carried volcanic high density flow subfacies is high natural gamma and high resistivity,the curve is in the shape of high amplitude finger,and the imaging logging shows high resistance bright color.The subaqueous landing subfacies is high natural gamma and low resistivity,the curve is low amplitude flat or in the shape of high amplitude finger,and the imaging logging shows low resistivity dark.The exoclastic pyroclastic sedimentary rock subfacies is low natural gamma and high resistivity,the curve is in the shape of high amplitude finger,and the imaging logging shows high resistivity bright color.The lithology logging recognition chart is established and the subaqueous eruptive volcanic lithology logging recognition is achieved.