【作者】 陆娜；

【导师】 印兴耀；

【作者基本信息】 中国石油大学 ， 地球探测与信息技术， 2008， 硕士

【摘要】 叠后波阻抗反演使用全角度叠加的地震资料,削弱了反映储层特征的敏感性;叠前AVO分析和反演能够提供丰富的岩性参数,但受噪音的影响较大。弹性阻抗反演克服了二者的缺点,既保留了叠前资料丰富的信息,又受噪音影响较小。但弹性阻抗是一个计算出来的量,其物理意义不明确,因而,需要开展从弹性阻抗中提取岩石物性参数的研究。流体识别是储层预测的重要内容,流体因子方法的研究对流体识别具有重要的意义。本文首先阐述了不同弹性阻抗方程的基本理论,并对多种弹性阻抗方程的精度进行了对比分析;继而,阐述了弹性阻抗反演的基本理论和关键技术;接下来,根据实际地震资料的特点,分别就两种情况下从弹性阻抗中提取岩性参数的方法进行了研究。(1)在大角度入射情况下,通过对弹性阻抗方程进行线性变换,可以从三个弹性阻抗体中直接提取纵、横波速度和密度;在对参数提取方程做适当的变换后,推导出了直接从弹性阻抗中提取纵、横波阻抗和密度的方法。(2)在小角度入射情况下,如果无法得到三个角度叠加数据,通过合理的近似,简化参数求解方程,给出了直接从两个角度弹性阻抗数据体中提取纵、横波阻抗或者直接提取横波阻抗的方法。之后,通过不同岩性参数之间的关系计算得到其他参数。得到各种岩性参数后,对流体因子方法进行分析研究,结合井资料的分析进行流体识别。基于AVO分析的流体识别方法可以很好的区分含气储层;泊松阻抗方法和基于Gassmann方法的流体识别方法通过选择合理的参数,可以有效区分不同流体。最后,将本文研究的各种方法在垦东北地区和永新地区实际资料中进行了检验和应用。应用效果表明,文中讨论的方法是可行和有效的。更多还原

【Abstract】 As poststack acoustic impedance inversion use the seismic data of full angle multiple stack, it weakens the reflection sensitivity of reservoir character. AVO analysis and inversion provides various lithology parameters, but it can be easily affected by many kinds of noise. Elastic impedance inversion approach overcomes the limitations of acoustic impedance inversion and AVO method, which preserves the information of prestack data, also avoids the effects of noise. However, elastic impedance is a parameter that can only be calculated out, therefore it has no clear physical meanings. So that it is quite valuable to carry out research on extracting lithology parameters from elastic impedance. Fluid identification is one of the most main contents of reservoir predication, so it is very important to analyze the fluid factors for the fluid discrimination.This paper introduces the basic theory of elastic impedance function firstly, and analyzes the precision of different kinds of elastic impedance equations. Then, introduces the basic theory and pivotal technology for the elastic impedance inversion. After that, I study the methods of extracting lithology parameters from elastic impedance under two situations according to the characteristic of real seismic data: first, when the incidence is big, by linear transforming to the elastic equations, the compressional and shear wave velocity and density can be extracted directly; in addition, I rewrite the equation for parameter extraction and derive an equation that can be used as extracting compressional and shear wave impedance and density directly from elastic impedance. Secondly, when the incidence is small, it is hardly to get three angle gather stack datum, I simplify the solution equation by using reasonable approximation, and then present the approach for estimating compressional and shear wave impedance or only shear wave impedance directly from elastic impedance. Whereafter, according to the relationship of different lithology parameters, the other parameters can be calculated. Besides, after getting the litholoty parameters, I analyzes the fluid factor methods, which can discriminate the different fluids with well log data analysis. The methods of fluid factor based on AVO analysis can discriminate gas sand. The methods of fluid factor based on Gassmann equation and Poission impedance can discriminate different fluids effectively by choosing different parameters. At last, I tests and applies those approaches discussed before into the exploration of Keneast and Yongxin oil field. The result shows that discussed methods in this paper are feasible and effective.更多还原