基于标准差统计的窄方位角叠前裂缝预测方法

发布时间：2018-11-21 07:45

【摘要】：适用于宽方位角地震数据的常规叠前裂缝检测方法,对大多数窄方位角地震数据难以奏效。为此,本文提出一种基于标准差统计的叠前裂缝预测新方法。该方法的理论基础是地震波在各向异性介质与各向同性介质中传播时会出现一定的AVO差异效应,该差异可细分为两部分:1相同方位角条件下,随入射角变化的AVO曲线间差异;2相同入射角条件下,随方位角变化的AVO曲线间差异。首先利用测井资料和岩石物理模型分析构建研究区背景模型;再对区内窄方位角地震数据进行叠加,得到叠加后的方位角道集数据;然后统计目的层段内各个时间采样点的AVO曲线与背景模型的AVO曲线的差值,并以此差值的标准差表征该时间采样点的裂缝发育强度。渤海M区实际资料的应用效果表明,利用该方法取得的裂缝检测结果与研究区内测井资料解释结果的符合率超过80%。
[Abstract]:The conventional prestack fracture detection method suitable for wide azimuth seismic data is difficult to work for most narrow azimuth seismic data. In this paper, a new method of prestack fracture prediction based on standard deviation statistics is proposed. The theoretical basis of this method is that there is a certain AVO difference effect when seismic waves propagate in anisotropic medium and isotropic medium. The difference can be subdivided into two parts: (1) under the same azimuth condition, the difference between AVO curves varying with incident angle; 2 the difference of AVO curves with azimuth changes under the same incidence angle. Firstly, the background model of the study area is constructed by using log data and rock physical model, and then the seismic data of narrow azimuth angle are superposed to obtain the data of the stack azimuth trace. Then the difference between the AVO curve of each time sampling point in the target layer and the AVO curve of the background model is analyzed, and the standard deviation of the difference value is used to characterize the fracture development intensity of the time sampling point. The application results of the actual data in M area of Bohai Sea show that the coincidence rate between the fracture detection results obtained by this method and the interpretation results of the logging data in the study area is more than 80%.
【作者单位】：油气藏地质及开发工程国家重点实验室(成都理工大学);
【基金】：国家自然科学基金项目“Gassmann方程的关键技术研究及其应用”(41274130)资助
【分类号】：P631.44

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