浅海磁性源瞬变电磁探测技术及其应用研究

Technology of shallow sea magnetic sources TEM detection and its application

我国海洋资源开发与空间利用的力度逐年增强,为了实现更加高效率、低成本、广覆盖的地球物理探测,基于移动平台的瞬变电磁软硬件技术发展迅速,为浅海拖曳式磁性源瞬变电磁探测技术发展提供了有利条件.本文以浅海拖曳式磁性源瞬变电磁探测系统为研究对象,通过三维正演模拟分析了浅海磁性源瞬变电磁传播规律及响应特征,在此基础上给出适用于任意发射波形条件下的全域视电阻率定义方法.接着,采用OCCAM方法对浅海瞬变电磁数据进行反演,并通过数值模拟考察了该方法的适用性与稳定性.最后,设计浅海拖曳式磁性源瞬变电磁探测系统并采用该系统开展浅海试验研究.理论数值分析和海上试验结果表明,拖曳式磁性源瞬变电磁系统能够快速、准确获得水下异常体的信息.未来将浅海拖曳式磁性源瞬变电磁系统应用于海底管道探测、水下残骸搜寻及资源勘探等领域将具有可观的应用前景.

The development of marine resources and space utilization in China has been increasing every year,in order to achieve high efficiency,low cost and wide coverage of geophysical exploration,the software and hardware technology of transient electromagnetic detection based on mobile platform has developed rapidly.All these provide favorable conditions for the development of shallow sea towed magnetic source Transient Electromagnetic(TEM)detection technology.In this paper,we focus on the shallow sea towed magnetic sources TEM system.The propagation law and response characteristics of shallow sea magnetic sources TEM are analyzed by three-dimensional forward modeling.On this basis,the definition method of the full domain apparent resistivity is given under the condition of arbitrary emission waveform.Then,OCCAM method is used to retrieve shallow sea TEM data,the applicability and stability of this method is investigated by numerical simulation.Finally,a shallow sea towed magnetic source TEM detection system is designed and used to carry out shallow sea test.Theoretical analysis and shallow sea experiment results show that the towed magnetic TEM system can quickly and accurately obtain the information of underwater anomalous bodies,and the detection results are in good agreement with the practice.In the future,the towed magnetic source TEM system in shallow sea will have considerable application prospects in the fields of underwater pipeline detection,underwater debris search and resource exploration.