深海级分布式光纤地震系统的南海海试  

Field Trial of Deep-Sea Distributed Acoustic Sensing System in South China Sea

作　　者：邓棣珉 徐团伟[1,2] 张汉羽 于春亮 曹凯 姜英豪 谢亚宁 李芳 吴时国[3] Deng Dimin;Xu Tuanwei;Zhang Hanyu;Yu Chunliang;Cao Kai;Jiang Yinghao;Xie Yaning;Li Fang;Wu Shiguo(State Key Laboratory of Transducer Technology,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;Laboratory of Marine Geophysics&Geo-Resources,Institute of Deep-Sea Science and Engineering,Chinese Academy of Sciences,Sanya 572000,Hainan,China;Deep-Sea Engineering Technology Department,Institute of Deep-Sea Science and Engineering,Chinese Academy of Sciences,Sanya 572000,Hainan,China)

机构地区：[1]中国科学院半导体研究所传感技术国家重点实验室,北京100083 [2]中国科学院大学材料科学与光电技术学院,北京100049 [3]中国科学院深海科学与工程研究所深海地球物理与资源研究室,海南三亚572000 [4]中国科学院深海科学与工程研究所深海工程技术部,海南三亚572000

出　　处：《光学学报》2024年第1期367-375,共9页Acta Optica Sinica

基　　金：国家重点研发计划(2023YFC3010700);崖州湾科技城科研项目(SKJC-2020-01-009);中国科学院先导专项(XDA22040105)。

摘　　要：分布式光纤声传感(DAS)技术将单根光纤视为传感和传输介质,可实时探测光纤附近的振动/声波信号,具有环境适应性强、长距离、空间连续测量等优势。本文借助海底观测平台,将DAS解调仪与传感光纤一同布放于深海,展开了为期21天的深海原位测试试验。在1423 m的深海环境中,成功实现海底振动传感系统,其平均背景噪声约为0.464 mrad/√Hz。这一结果与实验室测量结果相近。海试的数据采集结果进一步验证了该系统的可行性,通过对不同工作状态(入水、着底、移动和抛载上浮)下采集到的振动信号的时频特性进行了分析,能够清晰识别出各工作状态下的信号特征。该深海级分布式光纤地震系统提供了一种新的工程方案,海底的原位布放可以实现在更远海域和更深海底的分布式光纤地震采集,对海洋地球物理研究具有重要意义。Objective Distributed acoustic sensing(DAS)technology regards the same optical fiber as both a sensing and transmission medium,enabling real-time capture of vibrations and acoustic signals in the vicinity of optical fibers.This technology features robust environmental adaptability,high sensitivity,and exceptional resistance to electromagnetic interference.DAS can transform optical cables spanning tens of kilometers into evenly distributed arrays for vibration and acoustic sensing,thus achieving spatial sampling resolutions of less than 1 m.Consequently,it has caught significant attention in fields such as oil and gas exploration and marine geophysics.However,the maximum sensing range of DAS is constrained by optical source bandwidth and stability,with the current maximum sensing range limited to approximately 100 km.Therefore,employing DAS for intercontinental undersea long-distance communication cables poses significant challenges.We introduce a DAS seabed in-situ monitoring system integrated with an underwater experiment platform,coupled with relevant offshore trials.This deployment extends DAS capabilities to more remote and deeper-sea areas.The analysis of offshore trial results validates the system feasibility.In the future,consideration can be given to combining submersible technologies for laying sensing optical cables on the seabed,which holds substantial significance for advancing marine geophysical research.Methods We employ pressure chamber technology to construct a deep-sea DAS system capable of withstanding pressure at depths of up to 10000 m and conduct rigorous pressure testing in the laboratory,subjecting the system to pressure of up to 110 MPa.Subsequently,the system is deployed on a deep-sea in-situ experimental platform equipped with autonomous underwater mobility capabilities and is placed at a depth of 1423 m for in-situ testing.Throughout the sea trial,the base station undergoes various operational states including submersion,landing,moving,and raising,with distinct vibration data generated

关 键 词：海底分布式光纤地震系统 分布式光纤声传感 海洋环境监测 海洋地球物理 

分 类 号：P315.62[天文地球—地震学] TP212.14[天文地球—固体地球物理学]