三塘湖盆地火山岩岩性识别方法

火山岩岩性识别是火山岩储层评价的基础和关键。以三塘湖盆地火山岩为例,石炭系卡拉岗组火山岩岩性复杂多样,发育熔岩、火山碎屑岩及过渡岩类。针对岩性识别难点,在区域重磁资料圈定火山岩岩体范围的基础上,优选对岩性反应敏感的自然伽马、电阻率、补偿密度及声波时差等测井物理量,并对其进行岩心、薄片资料精细刻度,采用交会图方法,建立火山岩的测井响应识别模板,实现了对火山岩的测井岩性识别,进而对地质录井岩性进行准确的校正,为深入开展三塘湖盆地火山岩勘探奠定良好的基础。

Methods for Lithology Discrimination of Volcanics in Santanghu Basin

Lithology discrimination of volcanics is the basis and key to volcanic reservoir evaluation.Taking the volcanics in Santanghu Basin as example,the volcanics lithology in Carboniferous Kalagang Formation is complicated;lava,volcanoclastic rock,and transition rock developed in the Formation.Aimed at the difficulties in lithology discrimination,on the basis of delinating the rock mass range of volcanics based on regional gravity and magnetic data,physical quantity including gama,resistivity,compensated density,and interval transit time sensitive to lithology is selected;detailed calibration is conducted on core and thin section data.Crossplot is used to set up the log response discrimination mask of volcanics,realizing log lithology discrimination of volcanics and then correcting geological logging lithology precisely.This provides solid basis for volcanics exploration in Santanghu Basin.