沙漠区地震资料层间多次波处理策略

在沙漠区勘探中, 由于复杂近地表和巨大沙丘的影响, 地震资料品质普遍较低, 且由于地下强反射层的存在, 目的层有效信号弱、多次波能量强, 现有的层间多次波预测和压制方法很难奏效, 特别是数据驱动的层间多次波压制方法对地震资料的品质要求更高。针对沙漠区地震资料特点, 提出了一种以逆散射级数法为核心的多方法联合多次波压制新策略。该策略首先提高沙漠区地震资料信噪比, 然后利用层位约束改进逆散射级数算法, 组建形成一套以逆散射级数法为核心的具有针对性的多方法分类、分域、逐级多次波压制处理流程。西部某工区实际资料的测试结果表明, 新策略不但能有效提高资料信噪比和分辨率, 还能有效压制目的层多次波, 保护有效波并改善断裂和储层成像质量, 从而为综合解释和目标评价提供更可靠的资料保障。

Due to the influence of complicated near-surface conditions and huge sand dunes, desert seismic data generally suffer from the problems of low quality and weak signals in the zones of interest.In addition, with the existence of subsurface strong reflectors, the internal multiples are extensively developed and they are difficult to predicted and attenuated using existing demultiple methods, especially for the data-driven demultiple methods which require higher data quality.To solve these problems, we propose a new strategy by combining the useful and effective demultiple methods with a horizion-constrained inverse scattering series algorithm as the key component.Field data in western China tests show that the new strategy improves the signal-to-noise ratio and resolution of seismic data by effectively suppressing internal multiples and protecting primaries in the target zone.Thus, it improves the imaging quality of faults and reservoirs, and provides a solid data foundation for subsequent interpretation and evaluation.