摘要
基于VTI介质的假设,通过结合单程波方程与VTI介质的时间偏移频散关系,发展了一种基于波动方程的VTI介质各向异性叠前时间偏移方法,给出了由均方根动校正速度与均方根各向异性参数确定的走时和幅值解析表达式。同时,综合分析速度与各向异性参数对CRP道集走时的影响,通过CRP道集内同相轴剩余动校时差的迭代拾取,实现了在偏移过程中偏移速度与各向异性参数的建模。理论模型试算和南海某深水区二维地震数据成像结果表明,应用VTI介质各向异性叠前时间偏移方法可以实现大角度倾斜界面更为准确的成像归位,同时能够保证剖面的能量聚焦效果。
On an assumption of VTI （vertical transverse isotropy） media,a wave-equation-based method of anisotropic prestack time migration in VTI media was developed by including the dispersion relation between one-way wave equation and time migration in VTI media,and the analytical expressions of travel time and amplitude were determined by the dynamic correction velocity of root mean square and the anisotropic parameter of root mean square.Meanwhile,the impacts of velocity and anisotropic parameter on CRP-gather travel time were comprehensively analyzed,and building models for migration velocity and anisotropic parameter was realized during migration by the iterative pickup of residual dynamic correction moveout in the events within CRP gathers.A testing of theoretical model calculation and the 2D seismic imaging in a deep water area,South China Sea,have shown that applying the method of anisotropic prestack time migration in VTI media can result in more accurate imaging of steep angled reflections and ensure energy focusing on seismic sections.
出处
《中国海上油气》
CAS
CSCD
北大核心
2014年第5期36-41,共6页
China Offshore Oil and Gas
基金
"十二五"国家科技重大专项"海上开发地震关键技术及应用研究(编号:2011ZX05024-001)"部分研究成果
关键词
各向异性参数
频散关系
VTI介质
叠前时间偏移
anisotropic parameters
dispersion relation
VTI media
prestack time migration
