Seabed Logging (SBL) is a method developed to detect the location of hydrocarbon reservoir below the seabed. This method, which uses Electromagnetic (EM) wave of low frequency, has shown highly promising results in the detection of hydrocarbon up to 1000 m deep below the seafloor. However, the method is not as successful in the detection of deeper target (>1000 m) due to the attenuation of EM wave. The objective of this research is to study the Magnetic Versus Offset (MVO) in the detection of deep hydrocarbon targets. CST software was used to simulate the environment and SBL setup and it was able to show the magnitude of electric field at various offsets. The MVO at various offsets was studied for targets from 500 m to 4000 m using EM of frequencies 0.125 and 0.0625 Hz. The results showed that the MVO at intermediate offset which ranges between -3000 m until -6000 m from the antenna demonstrated distinctive differences between the environments with hydrocarbon from the one without hydrocarbon in detection of deep reservoir. © 2012 American Institute of Physics.