地震波形分类技术应用条件及其在葡北地区沉积微相研究中的应用

Application conditions of seismic waveform classification technique and its use in the study of sedimentary microfacies of Pubei area

江青春 王海 李丹 曹锋 李秋芬 孙作兴 周慧

Jiang Qingchun Wang Hai Li Dan Cao Feng Li Qiufen Sun Zuoxing Zhou Hui

在应用地震相分析软件Stratimagic对葡北地区七克台(Q)组进行地震相分析的过程中,对地震波形分类技术的应用条件进行了对比。分析发现,频率大于40 Hz、信噪比大于25 DB的地震资料可以较好地满足地震波形分类的研究。构造形态平缓、断裂不发育的地区运用波形分析效果较好。此外合适的地震时窗大小的选取和适当的波形分类数的设定也影响波形分类分析的运用效果。一般5~8种分类数是比较合适的,与沉积微相类型的匹配效果较好。在此基础上,运用该技术编制了葡北地区七克台组的沉积微相,对比单井沉积微相分析结果发现,有86%以上的单井相分析结果与预测的沉积微相图吻合,证实了地震波形分类技术预测沉积微相的可靠性。最后,运用该技术预测了该地区的砂体展布,为该地区下步隐蔽油气藏的勘探指明了方向。

During analyzing the seismic facies of Qiketai(Q) Formation in Pubei(Pb) area with Stratimagic software,we compared the application conditions of waveform classification technique.Seismic data with a frequence greater than 40 Hz and a signal-to-noise ratio greater than 25 DB are suitable for seismic waveform classification.The effect of waveform analysis is good in area with gentle structural attitude and under-developed fractures.Furthermore,the selection of suitable seismic time window and the setting of proper waveform classification number also affect the application effect of waveform classification technique.Generally,a waveform classification number of five to eight is reasonable,which match well with the sedimentary microfacies types.This technique is used to map the sedimentary microfacies of Q Group.Comparison with single well sedimentary microfacies identification shows that the coincidence rate is more than 86%,verifying the reliability of sedimentary microfacies prediction by using seismic waveform classification technique.Finally,this paper presents the sandstone distribution predicted by using this technique which can be used to guide future exploration of subtle reservoirs in the area.

10.11743/ogg20120117