1D modeling of controlled-source electromagnetic (CSEM) data using finite element method for hydrocarbon detection in shallow water

The utilization of controlled-source electromagnetic (CSEM) method has gained tremendous interest among the offshore exploration community in these recent years. This application is especially significant in detecting hydrocarbon in shallow waters. The success of this method in the search of oil and gas reservoirs is due to the fact that hydrocarbon-saturated-reservoirs are characterized by very high resistivity, while the surrounding saline water formations are very conductive. Through these characteristics, the resistivity of the sea subsurface could be mapped via the electric and magnetic field data collected in CSEM survey. Modeling is done using finite element method, which is a flexible computational method that utilizes unstructured grids that can readily conform to irregular boundaries such as seafloor topography. This paper highlights the application of the finite element method in processing the CSEM data to produce the 1D model of hydrocarbon reservoir. The CSEM data is gathered through experiments using a 90-cm deep water tank that has been designed to represent the actual system of seabed logging. The obtained results show that the modeling method is capable to become an alternative solution in hydrocarbon detection.