Environmental Factor Correction（EFC）

Like static corrections in seismic to overcome various surface interferences, Environmental factor correction is critical in GMHD to compensate for differences in soil properties (PH, Salinity, etc.), and differences in ecological and environmental conditions (bio-facies, seasonal change, etc). A common EFC is salinity correction, which compensates for slow growth of microbes and low microbial population in soils with high salinity.

Example：

Microbial measurement was totally overprinted by salinity effect (low salinity, high microbial values) before EFC. It is only after environmental correction that the microbial anomalies can truly reflect the hydrocarbon microseepage intensity.