SIMULATION AND DESIGN TRANSMITTER FOR SEABED LOGGING (SBL)

Seabed logging (SBL) is an application of marine controlled source
electromagnetic (CSEM) method which is used to detect the location of oil reservoir.
A recently developed transmitter is using Horizontal Electric Dipole (HED)
transmitter based on electromagnetic (EM) surveying technique. The technique has
proven particularly useful for detecting thin and highly resistive layers of
hydrocarbon reservoirs. However, to detect the hydrocarbon reservoirs at very deep
seawater still remains a challenge. This project has come out with a new idea of
constructing twin curve antenna together with feeders which made from nickel zinc
ferrites to enhance the induced magnetic field. Aluminium is the best fit to this
project design since it has higher resistance corrosion, light, cheaper than copper and
also easy to fabricate. From the CST simulation, the shape of half ring antenna gives
greatest improvement on the amplification of EM wave as compared to the ring
shape. Later on, the investigation of the thickness and the curvature of the antenna
were observed. Three different diameters which is 0.38mm, I.OOmm and IO.OOmm
were tested and the results showed that the aluminium rod at a diameter of lO.OOmm
gives highest percentage of 12.79% improvement. The half ring shape gives better
result output with a slight increment of 16.80% as compared to the parabolic
curvature. The combination of magnetic feeders and the half ring antenna enhanced
the output of EM wave with 4 number of toroid gives the maximum amplification
signal of 7001%. Other method to amplify the input current signal is by using bridge
amplifier. Further improvement to the current design was done by combining two half
ring antennas with feeders and as mentioned earlier, it is called as twin curve antenna.
This antenna has been tested in a scaled tank filled with salt water and the
propagation of EM wave is improved at 388.53% comparing to the earlier design.