盐间页岩油韵律层地震响应模拟及页岩薄储层厚度预测  

Seismic Responses Simulation of Inter-Salt Shale Oil Rhythm Formation and Prediction of Layer Thickness of Thin Shale Reservoirs

作　　者：仉涛 郭智奇[1] 刘财[1] 刘喜武 刘宇巍[2,3,4] Zhang Tao;Guo Zhiqi;Liu Cai;Liu Xiwu;Liu Yuwei(College of GeoExploration Science and Technology,Jilin University,Changchun 130026,China;National Key Laboratory of Corporation of Shale Oil/Gas Enrichment Eechanism and Effective Development,SinoPEC,Beijing 100083,China;SinoPEC Key Laboratory of Shale Oil/Gas Exploration and Production Technology,Beijing 100083,China;SinoPEC Petroleum Exploration and Production Research Institute,Beijing 100083,China)

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]页岩油气富集机理与有效开发国家重点实验室,北京100083 [3]中国石化页岩油气勘探开发重点实验室,北京100083 [4]中国石化石油勘探开发研究院,北京100083

出　　处：《吉林大学学报（地球科学版）》2022年第1期281-291,共11页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(42074153)。

摘　　要：江汉盆地潜江凹陷潜江组页岩油储层的地质结构为韵律背景下的页岩薄层,由于地震分辨率的限制,常规地震勘探方法难以精确描述盐间页岩油薄储层厚度的空间展布。因此,应用现有地震资料,探索适用于韵律结构中页岩薄层的地震预测方法具有重要意义。本文通过地震传播矩阵方法计算并分析研究区目标韵律层的地震响应特征,系统模拟并分析非均匀薄互层结构中页岩薄层的厚度、纵波速度等变化时地震波的反射动力学特征,发现地震反射波形的振幅和相位随非均匀页岩薄层的纵波速度和厚度的变化产生明显的变化,这些变化是本文页岩薄层厚度预测的基础。结合测井分析构建韵律层地质地球物理模型,模型空间考虑了页岩薄层纵波速度和厚度共99种组合变化的情况。通过求取目标层实际地震反射波形与构建的模型空间中地震波形的最佳匹配,提出基于反射波形的页岩薄储层厚度的地震预测方法,预测研究区页岩薄层厚度变化范围为5~20 m,并且由西南向东北呈增加趋势。预测页岩薄层厚度与测井解释具有较高的一致性,验证了本文地震预测方法的有效性。The geological structure of shale oil reservoir of the Qianjiang Formation in the Qianjiang sag of the Jianghan basin is thin-layer shale under the background of rhythmic layers.It is difficult to accurately describe the spatial distribution of the thin inter-salt shale oil reservoir thickness by the conventional seismic exploration methods due to the limitation of seismic resolution.This study is based on the existing seismic data to explore the method of thin-layer seismic prediction suitable for shale thin layers in rhythmic structure.In this paper,the seismic propagation matrix method is used to calculate and analyze the seismic response characteristics of the target rhythmic layer in the study area and the dynamic characteristics of seismic reflection when the thickness and velocity of the target shale thin layer change in the non-uniform thin inter-bedded structure.It is found that the amplitude and phase of seismic reflection waveform change obviously with the velocity and thickness of the non-uniform shale thin layer.On this basis,combined with logging analysis,a rhythmic geological and geophysical model is constructed,with 99 combinations of shale thin layer velocity and thickness being considered in the model space.Through finding the best match between the actual seismic reflection waveform of the target layer and the seismic waveform in the constructed model space,a seismic prediction method of the thin shale reservoir thickness is established,and by which,the thickness of the thin shale reservoir in the study area is predicted:The thickness varies from 5-20 m,showing an increasing trend from southwest to northeast.There is a high consistency between the thickness of the predicted shale thin layer and that of the logging interpretation,which verifies the effectiveness of this seismic prediction method and provides important information for the identification and evaluation of shale oil reservoirs.

关 键 词：潜江凹陷 盐间页岩油 韵律层 地震响应 薄层厚度 地震预测 

分 类 号：P631.4[天文地球—地质矿产勘探]