双相介质薄砂层的地震反射特征分析  

Characteristic analysis of seismic reflections from a thin sand reservoir in two-phase media

作　　者：杨春[1] 王赟[1] 陈业全 张秉铭[3] YANG Chun;WANG Yun;CHEN Yequan;ZHANG Bingming(MWMC Research Group,State Key Laboratory of Geological Processes and Mineral Resources,School of Geophysics and Information Technology,China University of Geosciences,Beijing 100083,China;Research Institute of Petroleum Exploration and Development,SINOPEC,Beijing 100083,China;Oilfield Exploration and Development Department of SINOPEC,Beijing 100728,China)

机构地区：[1]中国地质大学(北京)地球物理与信息技术学院,地质过程与矿产资源国家重点实验室MWMC研究组,北京100083 [2]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [3]中国石油化工股份有限公司油田勘探开发事业部,北京100728

出　　处：《石油物探》2018年第2期186-197,共12页Geophysical Prospecting For Petroleum

基　　金：国家自然科学基金项目(41604119,41425017,41374131,41574126,41504107)以及国家科技重大专项“薄层地震波场特征与反演研究”(2016ZX05002005-008)联合资助。

摘　　要：针对含油气砂岩储层大多为双相介质薄储层的特点,利用薄层反射透射系数矩阵方程并结合Gassmann方程获得薄砂体储层的弹性参数、PP波及PS波地震响应,用以对比分析入射波频率、孔隙度、流体类型及流体饱和度对地震反射的影响。模拟分析结果表明:在薄层极性固定的情况下,薄砂层反射振幅随着频率的增大、孔隙度的减小而增大;中、低孔隙度下流体类型及饱和度的不同在地震响应上差异较小,高孔隙度下反射PP波振幅会显示出含气异常;相同孔隙度下,含气储层的泊松比较不含气储层的泊松比低,而在含油与含水情况下的泊松比相近。说明对于薄砂岩储层,利用反演泊松比的方法判别储层是否含气是可靠的,而区分油水层则缺乏足够的地震异常。Based on the fact that hydrocarbon-bearing sand reservoirs are mostly thin beds in two-phase media,the elastic parameters,PP-wave and PS-wave seismic responses from a thin sand model are simulated using thin-bed reflection/transmission coefficient matrix equations and the Gassmann equation.The influences of incident-wave frequency,porosity,fluid type,and saturation on seismic reflections are analyzed.Simulation and analysis results show that,a higher frequency and a lower porosity result in higher amplitudes of thin-bed reflected PP-and PS-waves for fixed thin-bed polarity.In cases of low and medium porosities,the difference in seismic responses from the thin sand reservoir with different fluid types and saturations is very small.For high porosities,PP-wave amplitude shows an obvious gas-bearing anomaly.With the same porosity,the Poisson s ratio of gas-bearing sand reservoirs is smaller than that of non-gas-bearing sand reservoirs,and the Poisson s ratio of oil-bearing sand reservoirs is very similar to that of water-bearing reservoirs.This means that for the thin sand reservoir,it is reliable to distinguish whether the reservoir has gas or not using Poisson s ratio inversion,but there are not enough seismic anomalies to discern the oil-bearing case from the water-bearing case.

关 键 词：砂岩储层 薄层 双相介质 流体替换 地震反射 

分 类 号：P631[天文地球—地质矿产勘探]