基于叠前时间偏移资料的AVO处理技术

AVO processing technique based on prestack time migration data

与国外的处理流程相比,国内AVO资料处理过程中一般不作归位处理,这使AVO资料在应用上受到一定限制。针对这一问题,在胜利油田永安地区的AVO资料处理过程中,使用克希霍夫叠前时间偏移技术对常规CMP道集进行归位,得到了CRP道集。在此基础上进行AVO分析,不但较好地解决了AVO异常的归位问题,而且叠前时间偏移使绕射能量归位,削弱了随机噪音的干扰,使AVO响应更清晰,提高了AVO资料的分析质量。介绍了AVO资料处理过程中叠前时间偏移的实现步骤,包括数据准备、偏移速度场的建立、偏移实现过程和偏移后CRP道集处理等,并结合实际资料进行了效果分析。

The AVO data processing workflow commonly used in China does not include migration, this makes the application of AVO data confined to some extent. To cope with this problem, the author applied Kirchoff pres-tack time migration method to the conventional CMP gather during the AVO processing on data from YA area of Shengli Oilfield. Prestack time migration makes diffraction energy convergent, reducing random noises. The AVO analysis performed on the migrated data does not suffer from the incorrect migration of AVO abnormalies, making AVO responses clear and reliable. This paper discusses the key steps of applying prestack time migration in the AVO data processing such as data preparation, construction of migration-velocity field, migration procedure and CRP gather processing after migration. The processing effects are demonstrated with real data.