数据品质对叠前时间偏移成像的影响

目前，叠前时间偏移处理技术广泛应用于油气田的地震勘探资料处理中，影响叠前时间偏移成像的最主要因素就是数据品质。四川盆地东部地区由于地表条件复杂，资料噪声较重，野外采集通常采用变化的观测系统施工，部分地段炮检距分布非常不均匀，造成资料品质不能满足叠前时间偏移的需要。通过对川东地区一条二维测线叠前时间偏移成像效果的试处理分析，总结出一套提高叠前时间偏移成像质量的技术方法，即利用偏移前道集去噪技术，提高道集资料信噪比；运用道内插技术，改变由于野外施工造成数据分布不均的现象。最终使得数据品质能够满足叠前偏移处理的条件。

Influences of data quality on pre-stack time migration

The technique of pre-stack time migration has been widely applied in seismic processing in oil and gas fields. Data quality is the major factor influencing pre-stack time migration. Surface conditions are complex in eastern Sichuan Basin and the noise level of the seismic data is high, so variable observation system is usually applied in field acquisition. The uneven distribu-tion of offsets in some areas may result in data quality being too low to meet the requirements of pre-stack time migration. Based on an analysis of trial pre-staeking time migration processing of a 2D seismic line in eastern Sichuan Basin, a set of meth-ods is are developed to improve pre-stack time migration, including the noise-remove technique for enhancing signal-to-npise ra-tio of the gather and the trace interpolation technique for eliminating uneven distribution of data. These techniques can make the seismic data qualified for pre-stack time migration.