Next generation focused transmitter for deep hydrocarbon reservoir detection in shallow water environment

Marine Controlled Source Electromagnetic (MCSEM) method has been widely accepted by the oil and gas industry to identify the high resistive hydrocarbon targets in the offshore environment. The given name of the method, Seabed Logging (SBL) recently uses a Horizontal Electric Dipole (HED) antenna that transmits low-frequency electromagnetic waves. While producing successful results in deep waters, the shallow water environment posed ambiguities in the received signals due to the waves reflected back from the sea water-air interface, called airwaves. In shallow water, the conventional omnidirectional HED transmits the signal in equal magnitude of the up and down going directions, welcomes the airwaves in larger magnitude thus masking the accurate prediction of hydrocarbon reservoir information. Therefore, there is a pervasive need to modify the conventional antenna that can disperse the airwaves and increase the resolution of the downgoing waves for the higher delineation of the hydrocarbon presence. This research work concerns with the novel design of the antenna given the name High Performance Antenna (HPA), that is capable of the higher resolution of the downgoing waves and decreased airwaves using dispersion. The attributes are achieved by making the straight HED curve. A number of curvatures were simulated in the specified SBL model in model where conventional HED showed its failure with the allocated resistivity contrast of 1:100. The curvature ratio 0.3 provided the best resolution among the other curvatures with the applied current of 1250A, oscillating at 0.125 Hz frequency. To test the specimen, for the first time the lab scale experiment is conducted with most of the elements from the real offshore environment. Thus, with the selection of scale factor 2500, the lab scale curve antenna is designed, simulated and tested in the stratified scale tank.