基于声波方程转换的三参数递进式全波形反演

为提高基于声波方程的多参数反演精度,研究了基于波动方程转换的多参数全波形反演方法,实现了基于声波方程的速度、密度、阻抗三参数全波形反演。首先利用阻抗速度方程实现低波数速度模型和阻抗模型的全波形反演建模;将该低波数速度模型作为初始速度模型,经过声波方程转换再利用速度密度方程实现从低波数到高波数的递进式速度反演和密度反演。同时通过加德纳经验公式的约束提高了密度反演的稳定性和精度。利用Overthrust模型数据进行测试,分别实现了主频10Hz和30Hz地震数据三参数全波形反演,结果表明主频30Hz地震数据全波形反演结果能够精细刻画起伏构造形态,且断层边界清晰,断面干脆,为精细地震勘探提供了更加可靠的速度和阻抗。

A multi-parameter full waveform inversion method utilizing wave equation transformation was developed,which realized the full waveform inversion of velocity,density,and impedance using the acoustic equation.The method was developed in order to improve the accuracy of multi-parameter inversion based on the acoustic equation.First,the full waveform inversion based on the impedance-velocity wave equation was used to obtain the low-wavenumber velocity and impedance.Subsequently,the low-wavenumber velocity was used as the initial velocity in the model,and the velocity-density full waveform inversion was implemented to realize a progressive velocity inversion from low wavenumber to high wavenumber,and the density inversion.Meanwhile,Gardner empirical constraints were utilized to improve the stability and accuracy of the density inversion.A three-parameter full waveform inversion was implemented on 10Hz and 30Hz seismic data from an overthrust model.The inversion results showed that the full waveform inversion using 30Hz data is able to delineate structural undulations,with clear fault boundaries and sections.Finally,it can be concluded that the proposed method can provide more accurate velocity and impedance data for fine seismic exploration.

国家重大研发计划(2017YFB0202904)资助。