逆散射级数和抛物线Radon变换联合的层间多次波压制策略

层间多次波给地震成像和解释带来极大挑战,单独使用基于波动方程预测或基于滤波的方法压制层间多次波效果都不理想,前者对数据的品质要求高且运算量大,而后者则很难处理规律性较差的层间多次波。基于此,提出了一种将逆散射级数法与抛物线Radon变换相结合的层间多次波压制新策略。首先在抛物线Radon域采用自适应非线性滤波对CRP数据中的一次波进行保护处理,将未受多次波干扰的一次波和含有部分一次波的多次波能量进行分离,然后在曲波域对滤波分离出的多次波能量和逆散射级数预测的层间多次波模型数据进行匹配相减,最后将相减得到的剩余一次波和滤波分离出的一次波相融合得到层间多次波压制后的结果。实际资料测试表明该策略能高效高精度压制层间多次波,使地层结构特征更为清楚,地震成像质量显著改善,从而为油藏解释提供更可靠的地震数据。

Suppression of internal multiples by combining inverse scattering series and the Radon transform

In seismic exploration,the signal from internal multiples is an undesired noise which cannot be easily suppressed through wave equation prediction or by a filter-based method alone.The former is computationally expensive and requires high data quality,while the latter is unable to process the internal multiples with poor periods.A new strategy is hence proposed which combines inverse scattering series and the parabolic Radon transform to attenuate the internal multiples in common reflection point gathers.In this strategy,an adaptive nonlinear filter in the parabolic Radon domain is first used to separate the primary waves from the multiples that containing primaries.Then,in the curvilinear domain,the multiples extracted by the filter and those predicted by the inverse scattering series are matched and adaptively subtracted.Finally the resulting residual primary waves and those extracted by the filter are fused together.Tests on field data showed that the proposed method can suppress the internal multiples efficiently and effectively,thereby significantly improving the seismic imaging.As a result,the stratigraphic structures could be highlighted more clearly,and more reliable seismic data for reservoir interpretation could be provided.