CSEM Data Sensitivity for Shallow Resistivity Anomaly

In this study, we explore some features of marine controlled-source electro-magnetic (CSEM) data with a particular focus on shallow resistivity anomaly’s sensitivity. CSEM application to exploration purpose is related normally to rather deep (typically >1km) resistivity targets. A shallow resistivity target may screen out the sensitivity of deep resistivity targets. In the context of monitoring, particularly for offshore geohazards in overburden, the shallow resistivity targets (e.g. shallow gas, CO2 leakage) are of main interest. Through this study, we find out interesting features in the interaction between shallow and deep resistivity targets, which may help us to improve marine CSEM data interpretation. The study is based on a set of CSEM data resulting from 3D simple synthetic models.