Implementing a feasibility survey
Feasibility survey, at least conducted in 1D, is always performed before any survey acquisition to evaluate what could be the response of a hypothetic reservoir containing hydrocarbon.
Thickness and resistivity – or conductivity – of the modeled layers are first defined based on geological knowledge. A set of parameters (source frequencies, source-receivers offset, noise level) are then tested to understand how a HC bearing layer could lead to an electromagnetic anomaly, seen on different components of the electric field.

• 0’’ → 30’’: Model is tuned to fit geology and fluid content layer. Orange layer of the final model corresponds to the hydrocarbon bearing reservoir layer under scrutiny.
• 31’’ → 2’31’’: Response of the model on the inline component of the Electric field is tested by screening parameters such as frequency, resistivity of the layer of interest, Transmitter- receivers offset, noise level. Normalizing of the HC bearing case with a water case is made to highlight signal content induced by the HC bearing layer only.
• 2’32’’ → 3’12’’: Chosen model has resulted in noticeable anomalies at 0.5 Hz. Hence user fixed frequency to 0.5, leaving results shown as color-coded maps to curves. Subtle anomalies could be observed, including phase shifts.