减小OVT片尺度的技术及应用

Technology and application of reducing OVT bin

OVT域处理技术是当前地震资料处理和解释的研究热点之一,OVT域的处理效果与OVT片尺度息息相关,而OVT片尺度取决于炮线距和检波线距。但现阶段地震资料,特别是老地震资料,其炮线距和接收线距较大(300~400 m),导致OVT片尺度较大,使得单片OVT数据的偏移距方位角属性一致性降低,从而影响了最终OVT域的处理效果。研究了减小OVT片尺度的处理技术,首先采用基于五维插值的检波线加密技术,加密一倍检波线,将炮线方向的尺度减小一半;然后在OVT片划分阶段,基于OVT域数据的互换原理,采用对折法优化OVT片划分,将检波线方向的尺度减小一半,最终达到将OVT片尺度减小一倍的目的。OVT道集内偏移距和方位角范围的减小,提高了OVT道集偏移距和方位角属性的一致性,改善了OVT域处理效果。实际应用结果表明:通过减小OVT片的尺度,达到减小OVT片的偏移距和方位角范围的目的,使叠前时间偏移效果得到有效改善,剖面的方位各向异性校正效果得到明显提升。

The wide-azimuth high-density offset vector tile(OVT)seismic processing method has received significant attention.Current seismic data are usually characterized by a low spatial density as the distance between source and receiver lines(300~400 m)is relatively large.This results in large OVT bins and a wide offset range of the OVT gather.As such,these seismic data are insufficient for OVT domain processing and hinder its utilization.Reducing the size of the OVT bin—thereby improving the effects of OVT processing—is extremely important for the popularization and application of this method.By analyzing the spatial characteristics of data in the OVT domain,a method to reduce the bin size was proposed.First,the receiver line interval was shortened using a five-dimensional interpolation technique,the OVT bin size in the source line direction was reduced by half.Second,the OVT bin size in the receiver line direction was shortened by adopting the fold method,based on the reciprocal of the OVT domain data.Test on field data showed that by reducing OVT bin size,the offset and azimuth range of OVT bin were reduced,the pre-stack time migration was improved,and the correction effect of azimuth anisotropy was also improved.