Prospects for Determination of Hydrocarbon Deposits in a Platform Autochthone under Thrust of the Pokuttya-Bukovyna Carpathians.

Abstract

Substantiation of prospects for oil and gas presence in the platform autochthone under the thrust of the Pokuttya-Bukovynian Carpathians. Complex analysis of drilling materials, seismic prospecting, information on the properties of reservoir rocks, oil and gas presence in nearby deposits, hydrocarbon outcrops, geochemicales criteria for oil and gas presence. 125 oil and gas deposits have been opened in Western Ukraine, of which 117 million tonnes of condensed oil and 309 billion m3 of gas have already been extracted. However, scientists estimate they compose only 36% of the initial total hydrocarbon resources. One of the most perspective sites in Western Ukraine is the autochthonous complex of the Neogene, Paleogene, Cretaceous and Jurassic of the Pokuttya-Bukovyna Carpathians, overlapped by the overthruts of the Boryslav-Pokuttya zone and Folder Carpathians. The Lopushnya oil deposit has already been discovered here. According to seismic data, fifteen promising objects have been discovered in the platform autochthone at a depth of more than 6 km. These are brachyanthiclines dislocated by faults, the area of which varies from 15 to 45 km2. They are grouped into several structural lines of the subcarpathian extension. By analogy with the Lopushnya field, deposits of Neogene, Paleogene, Cretaceous and Jurassic can be presence. Reasonable perspectives for oil and gas prospectiv of the identified objects, were grounded and their resource base was estimated by volumetric method. According to the results of structural-tectonic analysis of autochthone formations, study of the parameters of rock-reservoirs and oil and gas presence of the Lopushnya structure, with consideration of the surface oil-gas manifestations and aureoles of sulfide mineralization, as well as information on the oil and gas presence of the border areas of Romania and Poland, refined geological structure of the platform autochthone of the Pokuttya-Bukovyna Carpathians, reasonable hydrocarbon potential of the autochthonous complex in the amount of 268.1 million tons of oil. The complex of geophysical works and drilling of the first parametric well on the Yablunytska or Dychtynetska structures is proposed to clarify the geological structure and to estimate the industrial oil and gas content of the platform autochthone.