火山岩岩相-地震相响应关系及其应用——以三塘湖盆地马朗凹陷哈尔加乌组为例

摘要

In order to study the distribution characteristics and define the exploration direction of volcanic reservoirs of Haerjiawu Formation in Malang Sag of Santanghu Basin,it is necessary to establish the response relation between volcanic lithofacies and seismic facies,and carry out the identification and prediction of volcanic rocks.The cores and casting thin sections were used to define the lithologies and lithofacies characteristics of volcanic rocks.Combined detailed logging-seismic calibration and seismic response characteristics,this paper summarized the response relation between volcanic lithofacies and seismic facies,and then predicted the volcanic reservoirs.The study result shows that overflow facies and volcanic sedimentary facies are the main lithofacies of Haerjiawu Formation,and the seismic reflection characteristics mainly are weak swing and blank lenticular pattern,middle-weak swing and weakly continuous moundy pattern,middle-strong swing and moderate continuous lamellar phase.According to the prediction,it is considered that the volcanic rocks of Haerjiawu Formation has the characteristics of central type eruption,there are mostly layered volcanos or konides,and subaerial eruption and subaquatic eruption both can be found in the sag.The distributed area of mandelstone in mid-range crater is favorable for oil-gas exploration.%研究三塘湖盆地马朗凹陷哈尔加乌组火山岩地层油气藏的分布特征,明确勘探方向,有必要建立火山岩岩相与地震相响应关系并进行火山岩识别和预测。从钻井岩心和铸体薄片研究入手,在明确研究区火山岩岩性和岩相特征基础上,通过详细的井震标定,结合目的层的地震反射特征,归纳出岩相与地震相的响应关系,进而开展了火山岩储层预测。研究表明：哈尔加乌组火山岩岩相以溢流相、火山岩沉积相为主;地震反射主要表现为弱振幅空白透镜状反射相、中—弱振幅弱连续丘状反射相、中—强振幅中连续层状反射相;岩相识别和预测认为哈尔加乌组火山岩具中心式喷发特征,火山体呈层状或锥状,且具陆上和水下喷发并存的特征。结合成藏条件,认为中距火山口的杏仁状熔岩分布区是有利勘探区带。