消除厚度调谐影响的高阻抗储层孔隙度预测方法——以莺歌海盆地乐东10区为例

Porosity Prediction Method of High Impedance Reservoir by Eliminating the Influence of Thickness Tuning——A Case Study of Ledong Block 10 of Yinggehai Basin

莺歌海盆地乐东区深层主要发育高阻抗储层,在地震资料上储层顶面表现出明显的波峰型亮点特征。随着储层孔隙度增大,储层阻抗逐渐降低,地震波峰逐渐减弱,这一特征与地层减薄引起的变化规律一致。受资料频带限制,在利用常规波阻抗反演进行孔隙度预测时,薄层位置阻抗反演结果不能反映其调谐真实的阻抗值,储层孔隙度预测精度不高。针对这一问题,在区域岩石物理分析的基础上,提出消除厚度调谐影响的高阻抗储层孔隙度预测新方法。实际应用表明,新方法能有效去除厚度干扰,孔隙度预测准确率明显提高,利用新方法预测的储层孔隙度展布特征更加符合沉积规律。

In Ledong area of Yinggehai Basin,high impedance reservoirs are mainly developed in the deep layer and the top surface of the reservoir shows obvious wave peak type bright spot characteristics.With the increase of reservoir porosity,the impedance of the reservoir decreases and the peak energy of seismic wave decreases gradually,which is consistent with the variation law caused by the thinning of the formation.Limited by the frequency band of data,when using inversion impedance to predict porosity,the impedance of thin layer position inversion cannot reflect its true impedance value,and the accuracy of reservoir porosity prediction is not high.In order to solve this problem,a new porosity prediction method of high impedance reservoir is established to eliminate the influence of thickness tuning on the basis of regional petrophysical analysis.Practical application shows that this method can effectively eliminate the influence of stratigraphic tuning effect and improve the accuracy of porosity prediction.And the predicted porosity distribution characteristics are more in line with the sedimentary law.