Benthic nodal time-frequency dual-domain electromagnetic acquisition system and test

The 13th Five-Year Plan for scientific and technological innovation clearly requires the establishment of a technical system to safeguard national energy security and strategic interests, and the strengthening of strategic high-tech deployment in such fields as Deep Sea, Deep Earth, Deep Space and Deep Blue. Also it is of great significance to research and develop controllable source electromagnetic system for accelerating the research and development of offshore exploration technology. This paper introduces the working principle of the time-frequency dual-domain electromagnetic acquisition system with seabed nodes, describes the electromagnetic sensor, data acquisition station, acoustic unit and framework, analyzes the overall acquisition performance of the system, and finally demonstrates the performances and characteristics of the key links, such as data delivery, signal acquisition, release and recovery of seabed nodes. The interpretation result of the test section is consistent with the transverse change of the electrical property of the known gas-bearing reservoir, proving the system applicable. The system is suitable for industrial application and lays a foundation for promoting the industrial application of marine electromagnetic exploration technology in China. © 2021, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.