While seismic itself is mainly conducted using AS350'S, I assume the 212 might be better suited due to its higher load capacity.
I strongly recommend using Agrarflug-i work for them part time, and they are THE specialists when it comes to utility work in Europe...
I have done those projects for oil and gas before (e.g. for Rio Tinto in Congo and CAR), so let me know if you need someone for this project...