倾角导向的相干加强技术在改善复杂断块地震资料中的应用

Dip steering coherent-enhancing filtering and its application on seismic data of complex fault-block

断层的识别是断块型圈闭勘探开发的一项重要研究内容,尤其是到了油田开发阶段,需要对断层组合关系、小断层发育程度及储层连通性提出风险认识.然而地震资料中的随机噪声严重制约了断层的识别,无法满足开发阶段对小断层精细刻画的要求,需要对其进行衰减处理.常规的相干加强滤波方法在去噪过程中会损伤大量高陡地层的反射能量并造成断点模糊,为此本文提出了一种基于倾角导向的相干加强去噪方法,该方法首先运用平面波破坏滤波技术估算出地震体的倾角信息,然后将其作为倾角导向相干加强滤波的输入进行约束去噪.针对渤海KL油田在开发方案设计阶段的实际地震资料,利用本文提出的方法对其进行了处理,通过对比分析倾角导向滤波前后的剖面、方差切片以及振幅属性表明该方法在提高地震资料信噪比的同时很好地保护了断层等地震反射信息,对断块型油气藏中断层识别十分有利,展示了较好的实际应用价值.

The fault recognition is an important research content of fault-block trap prospecting and exploiting,especially in the stage of oil field development,and it is necessary to propose the risk of fault combination relationship, small fault development and the connectivity of different sands. However,the random noise restricts the fault identification seriously in seismic data,which can＇t meet the requirements of small fault identification,therefore we need an attenuation process. The conventional method of coherent enhancement filtering in the denoising process will cause loss to steep strata＇s reflection and make breakpoint fuzzy. So in this paper we put forward the method of dip steering coherent enhancement filtering. Firstly, the plane-wave destruction filter was used to estimate seismic body＇s dip information. Secondly, the dip information would be used as constraint during dip steering coherent enhancement filtering. We tested this method using an actual seismic data of KL oilfield,which is in the ODP design stage in Bohai Sea. Through contrasting the profile, variance slice and amplitude attribute before and after the dip steering filter,we find that the method could improve the signal to noise ratio of seismic data well,and protect the fault information well. This method is favorable for fault identification of fault- block trap,and shows good application value.