Conventional AVO inversion utilizes the trace amplitudes of CMP gathers. There are three main factors affecting the accuracy of the inversion. First, CMP gathers are based on the hypothesis of horizontal layers but mo...Conventional AVO inversion utilizes the trace amplitudes of CMP gathers. There are three main factors affecting the accuracy of the inversion. First, CMP gathers are based on the hypothesis of horizontal layers but most real layers are not horizontal. Greater layer dip results in a greater difference between the observed CMP gathers and their real location. Second, conventional processing flows such as NMO, DMO, and deconvolution will distort amplitudes. Third, the formulation of reflection coefficient is related to incidence angles and it is difficult to get the relationship between amplitude and incidence angle. Wave equation prestack depth migration has the ability of imaging complex media and steeply dipping layers. It can reduce the errors of conventional processing and move amplitudes back to their real location. With true amplitude migration, common angle gathers abstraction, and AVO inversion, we suggest a method of AVO inversion from common shot gathers in order to reduce the effect of the above factors and improve the accuracy of AVO inversion.展开更多
利用AVO(Amplitude Versus Offset)属性分析技术,对南海北部测线B进行了AVO属性处理,结合BSR(Bottom Simulating Reflector),振幅空白带以及波形极性反转等多种水合物赋存信息,对水合物成矿带及游离气带的AVO属性特征进行了综合研究。...利用AVO(Amplitude Versus Offset)属性分析技术,对南海北部测线B进行了AVO属性处理,结合BSR(Bottom Simulating Reflector),振幅空白带以及波形极性反转等多种水合物赋存信息,对水合物成矿带及游离气带的AVO属性特征进行了综合研究。结果表明:①AVO1和AVO9可用于检测BSR和水合物成矿带;②AVO4、AVO6、AVO9用于游离气带的检测;③AVO1高截距值表示上、下层P波速度差值大,弱反射或空白反射表示水合物分布均匀,是水合物富集和稳定的表现;④AVO4高值表示有游离气存在,强反射特征为游离气顶的反射;⑤AVO6正值,表示有游离气存在,强反射的发育厚度代表游离气的发育厚度;⑥AVO9低幅值表示水合物成矿带,正值表示游离气带。研究结果表明,高精度AVO分析不仅可以帮助寻找水合物矿点,还可以进一步判定水合物的富集层位。展开更多
基金This project is sponsored by the "Pre-Cenozoic Marine Oil and Gas Resource Research around the Bohai Area" of the Knowledge Innovation Project of The Chinese Academy of Sciences (No. KZCX1-SW-18)
文摘Conventional AVO inversion utilizes the trace amplitudes of CMP gathers. There are three main factors affecting the accuracy of the inversion. First, CMP gathers are based on the hypothesis of horizontal layers but most real layers are not horizontal. Greater layer dip results in a greater difference between the observed CMP gathers and their real location. Second, conventional processing flows such as NMO, DMO, and deconvolution will distort amplitudes. Third, the formulation of reflection coefficient is related to incidence angles and it is difficult to get the relationship between amplitude and incidence angle. Wave equation prestack depth migration has the ability of imaging complex media and steeply dipping layers. It can reduce the errors of conventional processing and move amplitudes back to their real location. With true amplitude migration, common angle gathers abstraction, and AVO inversion, we suggest a method of AVO inversion from common shot gathers in order to reduce the effect of the above factors and improve the accuracy of AVO inversion.
文摘利用AVO(Amplitude Versus Offset)属性分析技术,对南海北部测线B进行了AVO属性处理,结合BSR(Bottom Simulating Reflector),振幅空白带以及波形极性反转等多种水合物赋存信息,对水合物成矿带及游离气带的AVO属性特征进行了综合研究。结果表明:①AVO1和AVO9可用于检测BSR和水合物成矿带;②AVO4、AVO6、AVO9用于游离气带的检测;③AVO1高截距值表示上、下层P波速度差值大,弱反射或空白反射表示水合物分布均匀,是水合物富集和稳定的表现;④AVO4高值表示有游离气存在,强反射特征为游离气顶的反射;⑤AVO6正值,表示有游离气存在,强反射的发育厚度代表游离气的发育厚度;⑥AVO9低幅值表示水合物成矿带,正值表示游离气带。研究结果表明,高精度AVO分析不仅可以帮助寻找水合物矿点,还可以进一步判定水合物的富集层位。
