近程波场成像蓝色滤波高分辨率地震资料处理技术在提高川西北双鱼石地区栖霞组储层分辨率中的应用

High resolution seismic data processing technology based on blue filtering for near range lateral propagating compression wavefield imaging which is applied to increase the reservoir resolution in the Qixia Formation in the Shuangyushi of Northwest Sichuan

川西北下二叠系栖霞组储层薄、非均质性强,常规地震资料储层纵横向分辨率低.提高地震资料频率是增强储层识别能力的有效途径之一.首先,分析了共反射点道集地震响应机理,进而研究了川西北双鱼石栖霞组目的层共反射点道集不同传播路径波场地震响应的频率变化特征即法向或近于法向传播的地震波逐渐横向向远处传播时,其固有高频频率成份损失越来越多,法向或接近于法向传播的地震波固有高频成份损失最少,故而称之为“保持了固有高频频率”,简称“保频”;然后,叠加求和得到不同传播路径的叠加波场,进而研究其叠加均化效应频率变化特征即叠加求和具有降频的特性,随着偏移距增加,部分叠加地震数据的频率是降低的.二者研究结果都表明近程路径传播波场的地震频率最高,随着横向传播路径增加地震频率下降.在此基础上,选取共反射点道集近程传播波场数据进行叠加成像,得到近路程传播波场共反射点道集叠加原始高分辨率数据,对之做2次迭代蓝色滤波处理,进一步提高了地震数据分辨率,得到最终的高分辨率数据.川西北双鱼石工区实际应用效果较好,提高了栖霞组白云岩储层分辨率.

Lower Permian Qixia Formation reservoir in northwest Sichuan is thin and highly heterogeneous,and the resolution of conventional seismic data reservoir is low.Increasing the frequency of seismic data is one of the effective ways to enhance the ability of reservoir identification.Firstly,the seismic response mechanism of common reflection point gather is analyzed,and then the frequency variation characteristics of the different lateral propagating range seismic response of the common reflection point gather of the Qixia Formation in the Shuangyushi of Northwest Sichuan are studied.i.e,when a normal or nearly normal seismic wave gradually travels laterally to a far distance,the loss of natural high frequency components of normal propagation seismic wave field is gradually increased,however the natural high frequency components of seismic waves travelling in or near the normal direction is lost least,so it’s called“preserving the natural high frequency”,for short“preserving frequency”;then,the superposition sum gives the superposition wave field seismic data with different propagation path range,and then the frequency variation characteristics of the superposition homogenization effect are studied,i.e.,the summation of superposition has the characteristic of decreasing frequency,as the offset increases,the main frequency of partially stacked seismic data is reduced.The results of both studies above show that the seismic main frequency of the short-path propagation wave field is highest,the main frequency of seismic data decreases as the lateral travel path increases.Based on this study,the short-range propagated wave field data on the common reflection point seismic gather is selected for stacking imaging,obtained the original stacked high-resolution data of the short-distance propagated wave field common reflection point gather,then two times of iterative blue filtering are done for it,the resolution of seismic data is further improved,get the final high-resolution data.The application effect of Shuangyushi survey in northwest Sichuan is good,which improves the resolution of dolomite reservoir of Qixia Formation.