地震多属性分析在徐西地区营城组砂体识别中的应用

Application of seismic multi-attributes analysis in identifying sand bodies from Yingcheng Formation in Xuxi area

徐家围子断陷徐西地区营城组营四段砂砾岩储层发育、砂泥岩组合关系复杂、且横向变化快,单一属性描述该区砂岩发育状况比较困难。为了解决这一问题,首先对该区35口井的岩性、测井以及地震相特征综合分析,总结出了该区岩性发育的4种模式为厚砂(砂砾)岩、砂泥互层(砂岩厚度大)、砂泥互层(泥岩厚度大)及厚泥岩夹薄砂岩。在精细构造解释和属性提取的基础上,优选了频率带宽、均方根振幅及相对波阻抗等3种能对该区几种砂岩发育模式进行全面描述的敏感属性。并运用属性雕刻的方式,通过多属性分析对研究区营城组营四段砂岩发育区进行了预测。

The glutenite reservoirs are well developed in 4th member of Yingcheng Formation in western area of Xujiaweizi fault depression.The prediction of development of sand bodies with a single attribute is difficult due to the complex lithological combination and rapid horizontal variation.To solve this problem,4 patterns of lithologic development(thick sandstone or glutenite,interbeds of relatively thick sandstone and mudstone,interbeds of sandstone and relatively thick mudstone,and thick mudstone interbed with a few sand or siltstone)are summed up through analysis of lithologic characteristics,well logging information and seismic facies of 35 wells in Xuxi area.Based on the fine seismic interpretation,multiple seismic attributes have been extracted,finally the most sensitive attributes such as frequency bandwidth,RMS amplitude and relative wave impedance are optimized,which can comprehensively describe the sandstone development.The goal of predicting development of sand bodies in 4th member of Yingcheng Formation in Xuxi area is achieved by calculating strata slices and attribute engraving.