Marine Time Domain CSEM - The First Two Years of Experience

The CSEM method can measure and understand the fluid content and its changes in a pore space. The method is based on detecting the resistivity contrast of the resistive reservoir fluid to its conductive surrounding media. Recent advances in electronics now make it possible to reliably collect marine time domain electromagnetic data, or tCSEM™. As the tCSEM™ method records only the Earth’s response and is collected in a style similar to seismic, it can be robustly integrated with seismic data. By recording in the absence of the active source, the airwave phenomena also can potentially be isolated from the subsurface response in shallow water. Commercially available nodal systems have successfully collected marine tCSEM™ data and examples are discussed. New cable based systems are under development which contain densely spaced sensors for recording both the electric and magnetic fields. Combining cable and nodal systems will provide for more robust integration with seismic and borehole measurements.