东营凹陷浊积砂体叠后地震属性与储层物性相关性研究

Correlative analysis on post-stack seismic attributes and physical properties of reservoir in turbidite sandstone of Dongying Depression

东营凹陷牛庄洼陷沙河街组三段是典型的浊积砂体岩性油藏发育层段,地质构造相对简单。以一个钻探了20多口井的浊积砂体油藏为例,通过大量实测的砂层厚度、孔隙度、渗透率等物性参数和反射振幅、频率、能量等地震属性参数的统计分析,深入研究了该浊积砂体储层物性参数、地震属性及两者之间的相关性。研究结果表明:①孔隙度与渗透率、砂体厚度与砂层厚度、泥质含量与孔隙度等有较好的相关性;②振幅、能量类属性之间相关性较好,主频率与瞬时频率线性相关,但相关系数较低;③地震属性与储层物性之间存在一定的相关性,不同地震属性组合后与储层物性的相关性有很大变化;④样本的数量和分布对统计结果有较大的影响。基于这些认识,指导东营北带盐家-永安地区的岩性油气藏预测,计算的砂体孔隙度平均误差小于7%;史南地区浊积砂体储层物性的预测也取得良好效果。

The third member of the Shahejie Formation in Niuzhuang sag of Dongying Depression is typical for developing turbidite sandstone lithologic reservoirs with relatively simple structures.Take a turbidite sandstone reservoir with more than twenty wells as an example,we carried out statistical analysis on measured reservoir physical properties(sandstone thickness,porosity,permeability,etc) and post-stack seismic attributes(reflection amplitude,frequency,energy,etc) and their correlation.The results show that:①some pairs of physical properties has good correlation,such as porosity and permeability,sand-bodies thickness and sand-layer thickness,shale content and porosity;②the correlation between amplitude and energy is good,and dominant frequency and instantaneous frequency exist a linear relationship but the coefficient is low;③there are certain correlations between seismic attributes and the reservoir physical properties,but the correlation coefficients change greatly;④the number and distribution of samples have serious influence on statistic result.The above recognitions guided the prediction of lithologic reservoir in Yanjia-Yongan area of northern Dongying Depression.The average error of the achieved sand porosity is smaller than 7%.Meanwhile,the prediction result of physical properties of turbidite sandstone reservoir in Shinan area was remarkable.