强环噪地区可控震源高效混叠采集应用效果

随着高密度以及深层地震勘探的发展和普及,采集数据量随之急剧增加,常规采集方法已经不能有效地适应这些大数据量的勘探项目需求,高效地震采集方法成为必然.近几年来,混叠采集是较新发展的一种高效采集方法.本文在调研目前常用的混合源和同时源方法的基础上,总结提出了混叠采集的新概念.根据概念建立起理论正演模型进行模拟,模拟混叠采集方法与常规采集方法的区别、不同参数对混叠效果的影响等,得出相关的结论.在华北东部廊固凹陷进行了验证性试验.廊固凹陷地处华北平原,交通发达,村庄密集,存在较大的空炮率和超强的环境噪声,对资料品质有较大的影响,野外试验与模拟试验结果大致相同,也有一定的差异.与以往规则型的混叠方式不同,本研究在试验中创新性引入了任意随机与不同激发信号的混叠方式方法,取得了一些新的认识.研究结果表明:混叠采集方法能显著地提高生产效率;混叠带来的噪声可以通过不同域来去除;混叠采集需要一定的合适的空间间隔;混叠采集数据品质略差于常规方法,但可以通过提高采集密度和生产效率来弥补;混叠参数选取要考虑平衡施工效率、噪声水平和资料品质.

Application effect of vibroseis blending acquisition in strong noise area

With the development and popularization of high density and deep seismic exploration,seismic data has increased dramatically,the routine acquisition methods cannot adapt to the needs of these large data exploration projects any longer,so these high efficient seismic acquisition methods have become inevitable.Blending acquisition is one lasted high efficient acquisition method in recent years.Based on the investigation of the multi-sources and simultaneous source methods,this paper summarizes the concept of blending acquisition method.We established forward modeling to analyze the difference between blending acquisition and routine acquisition,and the influence of different parameters on the blending acquisition method etc.For comparison,field test were done in Lang-Gu depression,North China,where exists the strong ambient noise because of the dense village and busy traffic.The strong ambient noise has a greater impact on the quality of the data.Different from other regular blended methods,this research introduced innovatively two blended methods include absolutely random and different signals in field test,and got some new understanding.Finally,this research indicates these conclusions:the blending acquisition method can improve the production efficiency obviously;the blending noise can be removed in different domain;the suitable space spacing is necessary for blending acquisition;blending data is little weak than conventional method,but it can be strengthened by improving source density and production efficiency;the efficiency,noise level and data quality are the three functions should be considered while selecting blending parameters.