海上宽频地震勘探技术在琼东南盆地深水区的应用

Broadband marine seismic exploration in Qiongdongnan Basin deepwater areas

南海北部琼东南盆地深水区是中国近海极具潜力的油气勘探领域。该区具有水深变化大、海底崎岖、断裂发育等特点,造成中深层地震资料信噪比较低、地震反射能量弱、同相轴连续性差、断层及基底成像不清晰等,影响了勘探目标的综合解释研究及凹陷的资源评价。本文介绍了在该区采用的宽频地震勘探—检震空变采集、处理技术及其细节,在地震波的激发和接收等地震数据采集环节及资料处理过程中采用不同于常规海上地震勘探的各项技术,增强了地震资料的低频能量、拓宽了频带,尤其是中深层地震资料品质明显改善,取得了令人满意的地质效果。

Deepwater areas in Qiongdongnan Basin are one of the most important areas for China offshore oil and gas exploration.But low signal-to-noise ratio,weak energy at low frequency,event discontinuity and fuzzy basement are always shown in seismic data,especially in the middle and deep parts due to varying water depth,rugged ocean floor and complicated geology.This makes seismic interpretation more difficult.We present in this article a broadband marine seismic method with spatial-varying sources and receivers in data acquisition.More details of this method in data acquisition and processing are also discussed in the article.Better quality seismic data obtained by this method especially in the middle and deep parts.This may suggest in the future an effective way for seismic exploration in the region.