地震多属性分析在混积环境砂体识别中的应用——以桑塔木南地区石炭系Ⅳ砂组油为例

Application of seismic multi-attribute analysis in sand body identification of mixed sedimentation environment:A case study of Carboniferous sand group Ⅳ in the south of Sangtamu area

地震多属性分析是储层预测的重要手段之一。以塔河油田桑塔木南地区石炭系Ⅳ砂组油为例,在单井沉积相分析的基础上,优选振幅属性信息,进行AVF分频反演,建立振幅属性与砂体之间的耦合关系及砂体识别模式,刻画沉积相平面分布。将地震反射结构类型细分为4种类型;以Ⅳ砂组油层顶面为基准,上下浮动10ms进行平均波峰振幅属性提取,对灰质含量重的西南地区进行AVF分频反演;振幅属性与砂体之间总体存在正相关关系,砂含量越高,振幅值越大。水下分流河道主要分布在S1072井区及研究区西北缘;砂坪主要分布在AT10及S111井区,呈片状展布;潮砂脊主要分布在南部,可作为研究区岩性圈闭的重点目标区。

Aiming at the actual situation that the amplitude may be distorted in a mixed sedimentation environment,by using the example of CarboniferousⅣsand group in the south of Sangtamu area,based on the analysis of the single well sedimentary facies,we select the useful amplitude information in sandstone to perform AVF frequency-divided inversion,combine the results with attributes,establish coupling relationship between the amplitude attribute and the sand body,establish the sand body recognition mode,and characterize the plane distribution of the sedimentary facies.The seismic reflection structure type is subdivided into four types.Based on the top surface of theⅣsand group,the average crest amplitude attribute extraction was carried out 10 ms above and below,AVF frequency-divided inversion was carried out in the southwest with heavy gray matter content.There is a positive correlation between the amplitude attribute and the sand body,and the higher the sand content,the larger the amplitude.Underwater distributary channel are mainly distributed in the S1072 well area and the northwest margin of the study area.Sand flat are mainly distributed in the AT10 and S111 well areas,exhibiting a sheet.Tidal sand ridge are mainly distributed in the south,and can be used as a research area to find the key areas of lithologic traps.