摘要
常规的速度建模方法速度模型精度低,往往不能改善断层阴影带成像质量,通过采用混合域特征波全波形反演技术能加快全波形反演运算速度和收敛。同时提出成像剖面叠合分析、收敛性分析、测井速度与全波形反演速度对比分析、实际炮集与正演炮集波形对比分析、全波形反演模型与观测记录相似系数对比分析五步法全波形反演速度建模质控方法 ,并建立了目标泛函收敛是判断全波形反演是否收敛最直观的参数,目标函数不下降表明反演不收敛;全波形反演速度趋势与测井趋势要相吻合;正演炮集与实际炮集特征波对比越接近,目标泛函数值越小;正演炮集与实际炮集相似系数越大越一致,表明反演速度越精确等混合域特征波全波形反演速度建模质控主要标准。应用该质控方法,在较为准确的背景速度基础上应用构造约束混合域特征波全波形反演技术,引入较为准确的断层信息,建立精度更高的速度模型,提高了断层阴影带成像质量,有效改善了断层阴影带下盘构造成像畸变现象。
Conventional velocity modeling methods have insufficient accuracy to improve fault shadow zone imaging quality.Full waveform inversion technology of hybrid domain characteristic waves can accelerate the convergence and the inversion.We propose five-step quality control methods for full waveform inversion ve-locity modeling:imaging profile overlap analysis,convergenceanalysis,comparison analysis between logging ve-locity and full waveform inversion velocity,comparison analysis of waveform between actual shot gathers and forward shot gathers and comparison analysis of similarity coefficients between full waveform inversion models and observation records.The objective functional convergence is the most intuitive parameter of whether full waveform inversion converges.If the objective function does not decrease,it means that the inversion does not converge;the full waveform inversion velocity trend should be consistent with the logging trend;the closer the characteristic wave between the forward shot gathers and the real shot gathers,the smaller the objective func-tional value;the larger and more consistent the similarity coefficient between the forward shot gathers and the real shot gathers,the more accurate of the inversion velocityis.These above are the main quality control cri-teria for hybrid domain characteristic wave full waveform inversion velocity modeling.By using this quality control method,we applied the full waveform inversion technology of structural constraint hybrid domain char-acteristic wave based on relatively accurate backgroundvelocity,introduced relatively accurate fault informa-tion,established a higher precision velocity model,improved the imaging quality of the fault shadow zones,and effectively improved the imaging distortion phenomenon of the structure in the footwall of the fault shadow zones.
作者
李熙盛
胡光辉
Li Xisheng;Hu Guanghui(Shenzhen Branch,CNOOC China Limited,Shenzhen Guangdong 518054;SINOPEC Geophysical Research Institute,Nanjing Jiangsu 211103)
出处
《中外能源》
CAS
2024年第8期54-60,共7页
Sino-Global Energy
基金
中国海洋石油集团有限公司“十三五”科技重大项目“海相砂岩油田‘双特高’开发后期提高采收率技术”(编号:CNOOC-KJ135ZDXM22)。
关键词
全波形反演
混合域
速度建模
目标泛函
断层阴影
质控方法
full waveform inversion
hybrid domain
velocitymodeling
objective function
fault shadow
quality control method
