Surface Helium survey can be carried out at various stages of field development and be successfully applied in order to map drained/undrained areas of hydrocarbon-saturated reservoirs and  to locate residual oil reserves, which have not yet been involved in field development.


Correctly interpreted Helium data over a mature field shows:

- positive Helium anomalies as projections of undrained parts of the reservoir with active residual hydrocarbon reserves, sweet-spots and bypassed zones;

- negative Helium anomalies as the drained parts of the reservoir, low-pressure zones (including pressure cones) or flushed zones.