基于波形分解的重构地震数据体技术在致密油薄储层预测中的应用  

Application of reconstructed seismic data volume technology based on waveform decomposition in prediction of thin tight oil reservoir

作　　者：李奎周[1,2] 郑绪瑭 赵海波 杨志会[1] 周磊[3] LI Kuizhou;ZHENG Xutang;ZHAO Haibo;YANG Zhihui;ZHOU Lei(Exploration and Development Research Institute of PetroChina Daqing Oilfield Co Ltd,Daqing 163712,China;College of the Earth Sciences,Northeast Petroleum University,Daqing 163318,China;No.6 Oil Production Company of PetroChina Daqing Oilfield Co Ltd,Daqing 163114,China)

机构地区：[1]中国石油大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [2]东北石油大学地球科学学院,黑龙江大庆163318 [3]中国石油大庆油田有限责任公司第六采油厂,黑龙江大庆163114

出　　处：《大庆石油地质与开发》2022年第4期131-137,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家自然科学基金项目“基于数据驱动的逆散射级数层间多次波压制方法”(41974116)。

摘　　要：扶余油层属典型的致密油层,砂、泥岩速度密度相近造成其地震反射特征较弱。在弱反射特征与T2反射轴强屏蔽的共同影响下导致FI1油层组储层预测十分困难。针对这一问题,利用基于波形分解重构地震数据体技术,按照顺次共同使用的原则分别从子波分解与重构和波形分解2个方面对提高扶余油层致密油薄储层预测精度方法进行研究。第一步,利用褶积模型的逆运算将目标层段的地震数据分解为不同主频的地震子波序列,然后将分解得到的子波序列在选定的频率范围内进行重新组合,得到新的重构数据体;第二步,将新的重构数据体利用矩阵分解法分解为多个能量不同的基本分量,将各基本分量分别在剖面上与已知井钻遇砂岩厚度进行对比,选用能量变化与砂岩厚度变化规律一致的分量作为最终的成果数据;最后,将成果数据与原始地震数据同时进行属性分析,可明显发现前者的平面预测符合率更高。研究结果表明,基于波形分解的重构地震数据体技术可有效突出强反射背景下的薄储层弱反射特征,在致密油薄储层预测领域有很好的应用前景。Fuyu reservoir is typical tight reservoir with similar velocity and density of sandstone and mudstone,resulting in weak seismic reflection characteristics. Under joint influence of weak reflection characteristics and strong shielding of T2reflection axis,it is difficult to predict FI1 reservoir group. In view of this problem,with the help of reconstructed seismic data volume technology based on waveform decomposition,the methods to improve prediction accuracy of thin tight oil reservoirs in Fuyu reservoir are studied from two aspects of wavelet decomposition and reconstruction and waveform decomposition on the basis of sequential common use principle. In the first step,by using inverse operation of convolution model,the seismic data of target interval are decomposed into seismic wavelet sequences with different dominant frequencies,and then the decomposed wavelet sequences are recombined in selected frequency range to obtain a new reconstructed data volume. In the second step,the new reconstructed data volume is decomposed into multiple basic components with different energies by matrix decomposing method. Each basic component is correlated with sandstone thickness encountered in known wells on sections,and the components with the same energy change and sandstone thickness change law are selected as final result data. Finally,attribute analysis between the result data and original seismic data at the same time can obviously find that the areal prediction coincidence rate of the former is higher. The research shows that seismic data volume reconstruction technology based on waveform decomposition can effectively highlight weak reflection characteristics of thin reservoirs in the background of strong reflections,and has a good application prospect in the prediction of thin tight oil reservoirs.

关 键 词：子波分解与重构 波形分解 强屏蔽 致密油 

分 类 号：P631[天文地球—地质矿产勘探]