Controlled-source electromagnetics is a strongly efficient technique to explore deep-water marine hydrocarbon reservoirs. However, the shallow-water unsolved limitations of electromagnetic shooting methods still exist. In this regard, this work aims to alter the existing conventional electromagnetic source such that it can converge the down-going electromagnetic wave while simultaneously dispersing the up-going electromagnetic energy to minimise the airwave in shallow water. This work presents computed electric current distribution inside a modified transmitter, using a method of moments. Simulation and an experiment-based methodology are applied to this work. Finite element simulation of the response of the modified transmitter displayed the capability of the new transmitter in dispersing the airwave, by 15%. The experimental setup confirmed a better performance of the new transmitter, showing hydrocarbon delineation of up to 48%, compared to the existing conventional transmitter, with 25% oil delineation at the same depths in the same environment. Modification of the electromagnetic source to unbalance the up-down signals may have the potential to enhance the delineation magnitude of the target signal and, as a result, significantly improve oil detection capability.

中文翻译：

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提高海洋可控源电磁法效率的源修改

可控源电磁学是探索深水海洋油气藏的一种非常有效的技术。然而，电磁射击方法的浅水尚未解决的局限性仍然存在。在这方面，这项工作旨在改变现有的常规电磁源，使其可以汇聚下行电磁波，同时分散上行电磁能，以最大限度地减少浅水中的气波。这项工作使用矩量法展示了修改后的发射器内部计算出的电流分布。模拟和基于实验的方法应用于这项工作。修改后的发射机响应的有限元模拟显示新发射机的电波分散能力提高了 15%。实验装置证实了新变送器的更好性能，与现有的传统变送器相比，在相同深度的相同环境下，油气分离度高达 25%，油气分离度高达 48%。修改电磁源以不平衡上下信号可能有可能增强目标信号的描绘幅度，从而显着提高油液检测能力。