DEEP NATURE OF HYDROCARBON FLUID WITHIN THE BLACK SEASHELF BASED ON INCLUSIONS IN AUTHIGENIC MINERALS
The promising Pra-Dnieper (Pradniprovska) area on the outer Black Sea shelf has been selected for the processing of the rank geological information and its correlation.
Based on previous geophysical work and parametric wells drilling, we carried out the interpretation and obtained geological and geophysical sections from fragments of a number of regional geophysical profiles made by the Western Geophysical. The profiles clearly show areas of disturbance in the passage of seismic waves, which referred by us to as degassing pipes. Carried out by us in 2017-2018 gas survey of the bottom surface confirmed this assumption.
Evidence of vertical migration of deep hydrocarbon fluids on the north-western Black Sea shelf has been obtained using thermobaric geochemical parameters. In particular, within the detected degassing pipes on the Pradniprovska structure that is promising for oil and gas, methane and its homologues (over 85 vol. %) dominate in the inclusions in authigenic minerals from Jurassic limestone and veinlets, with rather high relative gas saturation (up to 1.0 Pa). These data, together with other oil and gas indicators for a number of geological structures, can be interpreted as important indicators of the deep nature of hydrocarbon fluids as well as deep hydrocarbon saturation of the bowels.