摘要
叠前深度偏移是获得地下构造映像的有效手段,而基于波动方程的叠前深度偏移方法对速度横向变化剧烈的地层有更好的适应性.分析基于单程波方程的相移法、相移加插值法、频率—空间域有限差分法、傅里叶有限差分法和基于双程波方程的逆时偏移方法,借助于地堑模型与盐丘模型,测试5种逆时偏移方法成像复杂构造的精度和适应性.结果表明,基于波动方程的叠前深度偏移方法可实现横向变速地下构造成像,相比于基于双程波方程的逆时偏移方法,单程波方程方法对垂直断层等高陡倾角构造成像有局限性;逆时偏移方法对垂直断层、盐丘下边界等复杂构造可以清晰成像,辅以精确的地层速度,逆时偏移方法在地震资料成像领域中有广阔的发展和应用前景.
Pre-stack depth migration is an effective approach to obtain the subsurface structures imaging,and pre-stack depth migration approach based on the wave equation has better adaptability to image formations with transverse velocity rapid changing.The paper investigates on phase shift(PS),phase shift plus interpolation(PSPI),finite difference(FD)in frequency-space domain,Fourier finite difference(FFD)based on one-way wave equation and reverse time migration based on two-way wave equation,explains its theoretical foundation and implementation,analysis advantages and disadvantages of each approach,tests its accuracy and adaptability by imaging complicated structure,such as graben model and Salt-2Dmodel.Result shows that,pre-stack depth migration based on wave equation can achieveimaging to transverse velocity changing structure,but compared to reverse time migration bases on twoway wave equation,one-way wave equation approaches have limitation for imaging high steep dip structure like vertical fault.While reverse time migration can clearly image complicated structure,like vertical fault and lower boundary of salt,supplemented by precise formation velocity,reverse time migration approach has broad prospects for development and application in the field of seismic imaging.
出处
《东北石油大学学报》
CAS
北大核心
2014年第4期39-44,96,共7页
Journal of Northeast Petroleum University
基金
黑龙江省教育厅科学技术研究项目(12511025)
关键词
叠前深度偏移
相移法
相移加插值
频率—空间域有限差分
傅里叶有限差分
逆时偏移
pre-stack depth migration
phase shift
phase shift plus interpolation
finite difference in frequency space domain
Fourier finite difference
reverse time migration
