论文详情
分布式光纤声波传感利用单根光纤作为传感单元,可实时捕捉光纤沿线的声波信号,是一种新型的空间连续声波采集技术。首次提出了基于分布式光纤传感技术的小道距海上光纤拖缆地震数据采集系统,拖缆中采用单根光纤依次缠绕在多个水听器骨架上进而形成水听器阵列,不需要添加额外的分离器件,大大简化了采集系统的复杂度和制造工艺。最终实现的光纤拖缆道间距为1m,系统的声压噪声本底优于-40dB ref Pa/Hz。驻波管标定结果表明,该技术实现的水听器具有较好的声压响应一致性,声压灵敏度约为-157.8dB ref rad/uPa。湖上测试结果进一步验证了该采集系统的性能,可以清晰地采集到初至波以及由于多种界面连续反射产生的续至波。该光纤拖缆地震数据采集系统为海上地震采集提供了一种新的技术方案,小道距可以实现更精细的海底矿体成像分辨率,促进了海域天然气水合物勘探开发技术的发展。
Distributed optical fiber acoustic sensors use a single optical cable as the sensing unit,which can capture the acoustic signal along an optical fiber in real time.This is a novel spatial-continuous acoustic acquisition technology.Combined with the distributed optical fiber acoustic sensing technology,an optical fiber marine towing cable seismic data acquisition system with a small trace interval was realized for the first time.In the cable,a single optical fiber was wrapped on multiple hydrophone skeletons to form a hydrophone array without adding additional separation devices,thereby greatly simplifying the complexity and manufacturing process of the system.The final trace interval of the optical fiber towing cable was 1 m,and the sound pressure noise floor of the system was better than -40dB ref Pa/Hz.The calibration results for the standing wave tube showed that the hydrophones realized by this technology have good consistency of sound pressure response,and the sensitivity was approximately -157.8dB ref rad/uPa.The lake test further verifies the performance of the towing cable system,which can clearly collect the preliminary wave and continuation waves generated by a variety of interface reflections.The optical fiber towing cable seismic data acquisition system provides a new technical method for marine seismic acquisition.The small trace interval can achieve finer imaging resolution of the seabed ore body,and then promote the development of marine gas hydrate exploration and development.
国家自然科学基金项目(6210030553)、广东省海洋经济发展(海洋六大产业)专项资金项目(粤自然资合［2020］045号)、中国博士后科学基金面上项目(2020M680228)和中国地质调查局国家专项(DD20190234)共同资助。