高分辨率地震资料在沉积微相与储层研究中的应用

Sedimentary microfacies and reservoir prediction from high resolution seismic data.

高分辨率地震资料的反射结构在一定程度上反映了沉积体的沉积结构和几何特征,结合区域沉积背景、波阻抗反演和层速度分析等可以有效地预测储层发育区。为此,在江汉盆地潜江凹陷新沟嘴组利用这一研究思路进行了储层预测和储集性能评价。①对高分辨率地震资料的采集和处理因素进行了分析；②利用去砂试验和合成记录进行了高精度地震地质层位的标定；③利用正演模拟和地震反射结构分析进行了沉积微相识别；④利用波阻抗反演和速度分析方法进行了储集体储集性能评价。在新沟嘴组下段发现了2个前积式反射结构和1个透镜状反射特征的分布区,分析认为,它们分别是水下分流河道侧向加积和河口坝沉积微相的地震响应。分别在2个砂体上部署了探井,均在新沟嘴组发现了油层,并获得了工业油气流。

High-resolution seismic data can be used to predict the distributions of microfacies and reservoir,complemented by sedimentary settings,impedance inversion and interval ve- locity analysis,because the reflection architecture demon- strates the sedimentary architecture and geometry of sand body.The process can be divided into four steps:1)Get- ting High-resolution seismic data including seismic data ac- quisition and processing;2)Calibrating horizon on seismic section,including creating synthetic seismogram using pri- mary well logging and creating well logging replaced the bearing reservoir by non-bearing reservoir parameters;3) Identifying the sedimentary microfacies,i.e.making the seismic data from 2-D geological model and analyzing the architecture of seismic reflection;4)Evaluating the reser- voir,including impedance inversion or interval velocity a- nalysis.Two progradation and one lenticular reflection sets had been recognized from the seismic data in Qianjiang de- pression of Jianghan basin,which were defined as two sub- aqueous channels and water-lain mouth bar deposits.Two progradation reflection set bodies had been drilling and sev- eral oil intervals had been found on the basis of impedance inversion and interval velocity analysis.