Hydrocarbon Characteristics of North Bulgarian Black Sea Coastal Zone

The study area comprises the northern Black Sea coastal zone of Bulgaria. The main purpose is to analyze geological characteristics of discovered hydrocarbon fields in this zone. Totally 6 hydrocarbon fields have been found in the coastal zone – one oil-gas commercial field and 5 small gas semi-commercial fields. The study of main geological characteristics of discovered hydrocarbon fields is based on results of previous studies for Bulgarian petroleum systems, which have been considered, and on our analyses of results from drilling, well log surveys and tests, as well from seismic and gravity-magnetic surveys. The gas composition in the discovered fields is very similar - it is dry gas (presented by methane) with almost full lack of heavy homologues. This gas is biogenic and sin-genetic. The discovered only one oil accumulation in Tyulenovo field in contradistinction from the gas fields is located in older carbonate reservoir with Valanginian age.