Electromagnetic (EM) techniques can be used to perform surveys of subterranean structures for identifying elements of interest. Examples of elements of interest in a subterranean structure include hydrocarbon-bearing reservoirs, gas injection zones, thin carbonate or salt layers, and fresh-water aquifers.
One type of EM survey technique is the controlled source electromagnetic (CSEM) survey technique, in which an EM transmitter, called a “source,” is used to generate EM signals. Surveying units, called “receivers,” are deployed within an area of interest to make measurements from which information about the subterranean structure can be derived. The EM receivers may include a number of sensing elements for detecting any combination of electric fields, electric currents, and/or magnetic fields.
Traditionally, an EM source is implemented with two electrodes, one mounted on the front and one mounted on the aft of an antenna. The two electrodes of the EM source are connected to the “+” and “−” terminals of a power source system. However, this traditional arrangement of an EM source does not provide flexibility, particularly in marine survey applications.