【摘要】 叠前同时反演是油气探测的一种有效工具.其理论基础是平面P波Zoeppritz方程计算的反射系数的近似,是入射角的函数.叠前同时反演可以利用三项或两项Fatti方程进行反演分析.本文针对实际油田的测井数据,利用反射率法模拟了仅包含P波一次反射记录,包含P波一次反射和P波层间多次波记录以及全波场地震记录,再利用叠前同时反演对合成地震记录进行反演研究.研究结果表明,在大偏移距处P波主要反射受到其它模式波的污染,从而影响了叠前同时反演结果的精度.对于薄互层介质当转换波影响严重时,使用小角度数据的两项AVO反演比使用大角度数据的三项AVO反演更合理可靠.更多还原

【Abstract】 Pre-stack simultaneous inversion is an effect tool in oil&gas detection.The theory of the method is based on an approximate plane P-wave reflection coefficient as a function of angle of incidence.Pre-stack simultaneous inversion can be used in a three-term or a two-term Fatti equation.In the paper,for well log data of real oil field,synthetic seismograms are computed by using reflectivity method and then the seismograms are inverted by simultaneous inversion.The studies show that P-wave primary reflection amplitudes are usually contaminated by interference from other wave modes at large offsets that can affect accuracy of the results of simultaneous inversion.For thin interbed layers,when converted wave affect primary reflection severely,a two-term AVO inversion using small angles is expected to be more robust than a three-trem AVO inversion that uses large angles.更多还原