塔里木盆地三叠－侏罗系地震地层学研究

Seismic Stratigraphy of Triassic-Jurassic in Tarim Basin

塔里木盆地三叠－侏罗系储层主要是各类三角洲的分流河道、水下分流河道、河口坝、三角洲前缘席状砂及河道砂、滨浅湖砂坝等沉积环境的砂体。地震地质层位标定及合成记录分析的结果表明：三角洲前缘沉积表现为强振幅连续平行相（Ａ相）反射；辫状三角洲（夹扇二角洲）前缘、滨浅湖、曲流河沉积表现为弱振幅不连续发散相（Ｂ相）反射。在此基础上分析全区地震反射特征，‘可预测沉积环境和有利储层的展布：在塔里木盆地东部湖盆的北部（ＹＭ１井至ＬＮ１井附近地区），三叠系辫状三角洲前缘沉积较厚，该区以东的Ｂ地震相等时差的高值区代表了滨浅湖砂坝沉积厚度较大的区块，是良好储层的分布区；在塔里木盆地南部，分布有多块等时差高值区，表明这些区块的砂体沉积厚度较大，是勘探的有利区域。

The reservoirs of Triassic-Jurassic in the Tarim basin consist mainly of sand deposits of distributary channel, underwater distributary channel river mouth bar,delta frontal sheet sand of various delta factes,river channel and chott sand bar factes. The analysis of seismogeological horizons and seismic synthetic records indicates that the lowamplitude discontinuous factes(B)are caused by deposits of braided delta front (fan delta front),lake sand bar and river factes,while high-amplitude continuous factes(A)by delta front deposits. On the basis above,the distribution of depositional environment and the favorable reservoirs in Triassic-Jurassic of the Tarim basin are predicted by analysing seismic responses.