The theory of the geochemical field, based on the phenomenon of sub-vertical fluid migration from oil and gas accumulations and formation of anomalous geochemical, geophysical, and biogeochemical fields in the sedimentary section, is the fundamental basis of direct geochemical methods.
The concept of application of geochemical prospecting, adopted at Sibgeocom LLC, is based on a systemic, complex study of the geophysical and geochemical parameters of the sedimentary section, based on the interconnection and interdependence of geochemical and geophysical fields in space and time, and most manifested in the phenomenon of paragenesis of zonal-annular anomalies in geochemical and geophysical fields over hydrocarbon deposits.
The repeated fact of the existence of dispersion halos of hydrocarbon gases (bitumen) and secondarily altered rocks over oil and gas deposits fixed in near-surface sediments, in water and air in the form of gas-hydrogeochemical, lithogeochemical, phytogeochemical, bitumen, and other anomalies is the methodological basis of geochemical methods. In a generalized form, the geological-geochemical model of the hydrocarbon deposit and dispersion halos, according to A.V. Petukhov (1993), is represented in the form of zonal-annular anomalies of geochemical indicators. In practice, various dispersion halos are observed, depending on the geologic-tectonic structure of the sedimentary section, the type of reservoirs, and the nature of their saturation.
The company applies a scientifically justified forecast of oil and gas habitat based on a comprehensive study of geophysical and geochemical indicators, based on their interrelationship and interdependence in space and time. The need for compulsory application of geochemical researches in complex with geophysical works lies in the fact that the material composition of rocks and their fluids, as well as their features, predetermine anomalous physical properties of the sedimentary section.
Geological and geochemical model of dispersion halos of the Bratsk gas condensate field 
Physicochemical model of oil and gas deposit