一种叠前地震多属性反演方法

介绍了一种借助于地震波弹性阻抗提高常规叠前地震反演的精度和可靠性,进而同时提取多种地层弹性属性参数的地震多属性反演方法。利用全波测井资料确定声波阻抗(AI)和弹性波阻抗(射线路径弹性阻抗)(REI);将共中心点(CMP)道集变换成角道集并进行部分角度叠加;利用常规叠前弹性阻抗反演流程分别对小角度叠加数据及中等入射角的部分叠加数据进行声波阻抗和弹性波阻抗(射线路径弹性阻抗)反演;对反演得到的声波阻抗和弹性波阻抗(射线路径弹性阻抗)数据进行道运算,得到与弹性密度比、储层岩性变化和孔隙流体成分密切相关的地震属性;确定储层岩性和孔隙流体性质。该方法仅需要近、中角度的地震数据,其他弹性属性参数是由弹性密度比与声波阻抗之间的关系通过道运算获得,提高了计算效率,可用于绝大多数采集条件下获得的地震数据叠前反演。

A method of prestack seismic multi attribute inversion

This paper put forward a seismic multi attribute inversion which is to improve the accuracy and reliability of conventional prestack seismic inversion and to extract a variety of elastic attribute parameters using seismic elastic wave impedance.The steps are as follows:Firstly,determine acoustic impedance(AI)and elastic wave impedance(raypath elastic impedance REI)from full wave logging data.Secondly,convert CMP(common middle point)gathers into angle gathers and then implement partial stack on angle gathers.Thirdly,carry out AI and REI on small and medium angle stack data using conventional prestack elastic impedance inversion technique.Fourthly,calculate elastic density ratio and other seismic attributes that are closely related to lithology and pore fluid on AI and REI data.Finally,determine reservoir lithology and pore fluid properties.This method requires only small and medium angle seismic data,and all other elastic parameters are from the elastic density ratio and acoustic impedance.