基于地震沉积学的沉积相精细刻画:以山西寺家庄矿15号煤层聚煤前后为例

Sedimentary Facies Fine Depiction Based on Seismic Sedimentology——A Case Study of Coal No.15 before and after Accumulation in Sijiazhuang Coalmine,Shanxi

基于地震沉积学的理论方法,以山西寺家庄矿太原组15号煤层为例,采用合成记录、井震联合标定、层位追踪、地层切片、属性提取等关键技术,建立岩性及沉积相与地震属性的对应关系,对15号煤层聚煤前后沉积相进行精细刻画。研究结果表明:平均振幅属性和高阶累量方差属性经属性融合后可用来预测目标地层砂地比以及沉积相平面展布特征;山西寺家庄矿太原组15号煤层聚煤前为障壁岛—潮坪—潟湖—潮坪沉积环境,聚煤后为潮坪沉积环境,并在潮坪沉积相中识别出了混合坪和泥炭坪两种沉积亚相。相较于沉积学,地震沉积学对研究区太原组15号煤层聚煤前后沉积相的刻画更为精细。

Based on seismic sedimentology theory and methods,taking the Taiyuan Formation coal No.15 in Sijiazhuang coalmine,Shanxi as an example,using synthetic seismogram,well-seismic combined calibration,horizon tracing,stratum slicing,attribute extraction etc key techniques have established corresponding relationship between lithology,sedimentary facies and seismic attribute,carried out fine depiction for coal No.15 sedimentary facies before and after accumulation.The result has shown that mean amplitude attribute and higher order cumulative variance attribute after attribute synthesis can be used to predict target strata total sandstone thickness to strata thickness ratio and sedimentary facies planar extension features.Sijiazhuang coalmine Taiyuan Formation strata before coal No.15 accumulation belong to barrier island-tidal flat-lagoon-tidal flat sedimentary environment,after coal accumulation belong to tidal flat environment,in which has identified mixed flat and peat flat two subfacies.Comparing to sedimentology,the seismic sedimentology depiction for sedimentary faces of Taiyuan Formation strata before and after coal No.15 accumulation is finer.