Results of Surface Geochemical Survey Integrated with Results of Seismic Survey in the Drzonowo, Biala Area, NW Poland

The paper reports on the surface geochemical studies with the free soil gas method in the area of Drzonowo and Biała structures located in the Pomeranian Synclinorium (northwestern Poland). The studies aimed to recognize relationships between the surface geochemical pattern and the geological model of the analyzed structures. Totally, 226 soil gas samples were collected from measurement sites located along the 3 seismics lines. The samples were analyzed with the gas chromatography for concentrations of methane, ethane, propane, i-butane, n-butane, and ethylene, propylene, and 1-butene. Methane concentrations varied from 1.1 ppm to about 13.7 vol%. Maximum concentration of total alkanes C2-C5 was 18.3 ppm and that of total alkenes C2-C4 was 0.555 ppm. The presence of anomalous concentrations of gaseous hydrocarbons in the soil gas evidences that in the study area subsurface oil and gas accumulations occur. The composition of the anomalies suggests that oil accumulations are dominant. Structures interesting for hydrocarbon exploration, above which the geochemical anomalies were recorded, should have well control. The presented results of surface geochemical survey integrated with results of seismic survey should improve the effectiveness of hydrocarbon exploration.