地震反射振幅随偏移距的变化隐含着反射界面两侧岩石物性及所合流体的信息．1985年Shuey等人把Zoeppriz方程简化后发现了AVO（Amplitude Versus Offset）分析方法并进入实用阶段，把振幅随偏移距增大作为识别真假“亮点”确定含气层的...地震反射振幅随偏移距的变化隐含着反射界面两侧岩石物性及所合流体的信息．1985年Shuey等人把Zoeppriz方程简化后发现了AVO（Amplitude Versus Offset）分析方法并进入实用阶段，把振幅随偏移距增大作为识别真假“亮点”确定含气层的标志．1988年美国一些研究人员根据墨西哥湾岩石纵横波波阻抗特性提出了对AVO分析的修改，纠正了“Rising means pay”的观点，使AVO分析方法向前发展了一步．本文在常规AVO分析的基础上，进一步在拟纵波和横嫂的反射系数之上计算纵波和横波的相对波阻抗．根据一定的砂岩和页岩的速度模式，研究相对纵波波阻抗和横波波阻抗的关系（其实质是纵波和谐带横波的速度函数），确定砂岩是否含有油气，从理论分析可知。油气显示并不绝对取决于AVO现象。
通过对潭口浅层气和西北、华北某些地区资料试验说明该方法对提高气蒇预测准确度有重要作用，效果良好．展开更多
The shear-wave velocity is a very important parameter in oil and gas seismic exploration, and vital in prestack elastic-parameters inversion and seismic attribute analysis. However, sheafing-velocity logging is seldom...The shear-wave velocity is a very important parameter in oil and gas seismic exploration, and vital in prestack elastic-parameters inversion and seismic attribute analysis. However, sheafing-velocity logging is seldom carried out because it is expensive. This paper presents a simple method for predicting S-wave velocity which covers the basic factors that influence seismic wave propagation velocity in rocks. The elastic modulus of a rock is expressed here as a weighted arithmetic average between Voigt and Reuss bounds, where the weighting factor, w, is a measurement of the geometric details of the pore space and mineral grains. The S-wave velocity can be estimated from w, which is derived from the P-wave modulus. The method is applied to process well-logging data for a carbonate reservoir in Sichuan Basin, and shows the predicted S-wave velocities agree well with the measured S-wave velocities.展开更多
For the complicated reservoir description of the GD oilfield, P-wave and S-wave elastic impedance inversion was carried out using pre-stack seismic data to accurately identify the lithology of the reservoir. The joint...For the complicated reservoir description of the GD oilfield, P-wave and S-wave elastic impedance inversion was carried out using pre-stack seismic data to accurately identify the lithology of the reservoir. The joint inversion was performed using three or more partial stacks to overcome the singularity of post-stack seismic inversion that can not satisfy the requirements of complex reservoir description and to avoid the instability of the inversion result caused by low signal-noise ratio in the pre-stack gather. The basic theory of prestack elastic impedance inversion is briefly described in this paper and, using real data of the GD oilfield, the key steps of angle gather wavelet extraction, horizon calibration, S-wave velocity prediction, and elastic parameter extraction were analyzed and studied. The comprehensive interpretation of multiple elastic parameters determined from log analysis is a key to improving the effect ofprestack seismic inversion.展开更多
基金supported by CNPC key scientific and technological project(2020B-4019)CNPC basic and prospective scientific and technological project(2021DJ4203)CNPC Engineering Technology R&D Company Limited scientific and technological project(CPET2022-12S).
文摘地震反射振幅随偏移距的变化隐含着反射界面两侧岩石物性及所合流体的信息．1985年Shuey等人把Zoeppriz方程简化后发现了AVO（Amplitude Versus Offset）分析方法并进入实用阶段，把振幅随偏移距增大作为识别真假“亮点”确定含气层的标志．1988年美国一些研究人员根据墨西哥湾岩石纵横波波阻抗特性提出了对AVO分析的修改，纠正了“Rising means pay”的观点，使AVO分析方法向前发展了一步．本文在常规AVO分析的基础上，进一步在拟纵波和横嫂的反射系数之上计算纵波和横波的相对波阻抗．根据一定的砂岩和页岩的速度模式，研究相对纵波波阻抗和横波波阻抗的关系（其实质是纵波和谐带横波的速度函数），确定砂岩是否含有油气，从理论分析可知。油气显示并不绝对取决于AVO现象。
通过对潭口浅层气和西北、华北某些地区资料试验说明该方法对提高气蒇预测准确度有重要作用，效果良好．
基金supported by the High-Tech Research and Development Program of China(Grant No.2008AA093001)China Petroleum & Chemical Corporation(Grant No.YPH08006)
文摘The shear-wave velocity is a very important parameter in oil and gas seismic exploration, and vital in prestack elastic-parameters inversion and seismic attribute analysis. However, sheafing-velocity logging is seldom carried out because it is expensive. This paper presents a simple method for predicting S-wave velocity which covers the basic factors that influence seismic wave propagation velocity in rocks. The elastic modulus of a rock is expressed here as a weighted arithmetic average between Voigt and Reuss bounds, where the weighting factor, w, is a measurement of the geometric details of the pore space and mineral grains. The S-wave velocity can be estimated from w, which is derived from the P-wave modulus. The method is applied to process well-logging data for a carbonate reservoir in Sichuan Basin, and shows the predicted S-wave velocities agree well with the measured S-wave velocities.
文摘For the complicated reservoir description of the GD oilfield, P-wave and S-wave elastic impedance inversion was carried out using pre-stack seismic data to accurately identify the lithology of the reservoir. The joint inversion was performed using three or more partial stacks to overcome the singularity of post-stack seismic inversion that can not satisfy the requirements of complex reservoir description and to avoid the instability of the inversion result caused by low signal-noise ratio in the pre-stack gather. The basic theory of prestack elastic impedance inversion is briefly described in this paper and, using real data of the GD oilfield, the key steps of angle gather wavelet extraction, horizon calibration, S-wave velocity prediction, and elastic parameter extraction were analyzed and studied. The comprehensive interpretation of multiple elastic parameters determined from log analysis is a key to improving the effect ofprestack seismic inversion.
