GEOTHERMAL EVOLUTION OF GAS HYDRATE DEPOSITS: BULGARIAN EXCLUSIVE ECONOMIC ZONE IN THE BLACK SEA

Cruise MSM34 measurements at 11 heat flow (HF) stations in the Bulgarian Exclusive Economic Zone are the first purposefully conducted for gas hydrates (GH) study in the Black Sea (German project SUGAR, January 15, 2014). A 2D conductive heat transfer model was created to study the changes of temperature (T) and HF in sediments, resulting from GH deposit formation. The depths of the boundaries between sediments with different physical parameters are determined by a 2D seismic record. Three hypotheses are verified: 1) GH deposits grow laterally; 2) the geothermal evolution of the cyclic growing process is described by 7 stages; 3) hypotheses 1 and 2 explain the diversity of anomalous geothermal fields over GH deposits. Results include a 7-stage geothermal evolution of a GH deposit associated with variations of T and HF. The times are determined when every stage process becomes stationary. This work provided a basis for a new quantitative study of GH by methods of marine geothermy.