海洋矿产调查中的海空联合电磁勘探模式研究

Study on the Mode of Marine and Airborne Electromagnetic Exploration In Marine Mineral Resources Investigation

快速高效的勘探方法对海洋地质和矿产资源保护意义重大,结合航空电磁和海洋电磁两种方法的优势以及海洋磁测的特点,提出海空联合电磁勘探模式,水中固定或拖拽大电流水平电偶极子激发源,空中采用无人或有人操纵飞行器承载磁传感器接收三分量磁场。采用海洋电磁一维频率域数值模拟程序,对空中三分量磁场与测线布置、发射频率、海水深度、储层埋深、储层厚度、储层电阻率及飞行器飞行高度等几个重要因素之间的关系进行了研究。结果显示,海空联合电磁勘探模式对浅海金属矿产等低阻异常的发现有明显效果,磁异常归一化幅度变化为-10%~80%,为海洋矿产资源的高效大面积调查提供了一条有效的途径。

It is of great and profound significance to protect marine geology and mineral resources by fast and efficient means of exploration. In this paper, joint of marine and airborne electromagnetic exploration mode was presented, which combined the advantages of marine electromagnetic method, airborne Electromagnetic method, and characteristics of airborne magnetic survey. With it, three-component magnetic field was received through magnetic sensor carried by drones or other manned aircrafts, while a heavy current electric dipole source was fixed or dragged in the water. By numerical simulation program of marine electromagnetic onefrequency domain, analysis was carried out on the relationship between magnetic fields of three-component in the air and several important factors such as survey line layout, launch frequency, depth of water, buried depths of reservoirs, reservoir thickness, reservoir resistivity, and flight altitude. The results showed that magnetic field of the mode had a strong response when met low-resistivity layer, with normalized abnormal magnitude changes of about 80%, which provided an effective way of large-area mineral resources survey. 10% marine