Sensitivity Analysis of Marine CSEM Surveys

Marine controlled-source electromagnetic method (MCSEM) is widely used now for offshore hydrocarbon exploration. In this paper we examine the sensitivity MCSEM surveys. We introduce a technique of electromagnetic (EM) data sensitivity analysis based on integrated sensitivity calculations for a survey formed by multiple transmitters and receivers. We use this technique to study the sensitivity of typical EM surveys to local inhomogeneities. We map the spatial distribution of a survey sensitivity with respect to the local anomalies of the conductivity of a geological formation. The calculated sensitivity values provide useful information for designing MCSEM surveys.