Here the Cretaceous and Paleogene flysh of the Duklya-Chornohora, Burkut, Magura, Marmarosh and Pieniny covers was studied that in the north-western sector of the Ukrainian Carpathians near the border of Poland and Slovakia (Lemkivsky segment) distinguish themselves by very inclined thrusts. Spatially the given tectonic units are within the limits of so called hydrothermal field unfavourable as a whole, as to the presence of hydrocarbons on a large scale here. But there were distinguished small plots with prevalence of hydrocarbons in the gas composition. Prospects of the potential for gas presence in the region should be connected with the areas that spatially gravitate towards Transcarpathian deep. Studied area consists of several tectonic units of the first order. These are covers located farther south-west of Krosno cover: Duklya-Chornohora, Burkut (Porkulets), Magura, Marmarosh and Pieniny covers, in the south-west the studied terrane is limited by the Transcarpathian deep, and farther west – by the state border of Ukraine and Slovakia, in the south-east – by the Rika Rriver, in the north-east – by the zone of joining of Duklya-Chornohora and Krosno covers. Prospects of the potential for oil end gas presence in the given area, as in the Folded Carpathians on the whole, should be determined by the complex of all accompanying parameters: structural, collecting and covering, hadrochemical and geochemical. For the given area of the Carpathians the geochemical factor is the most important.

In the paper a model of the formation of the folded-covering-block structure of the Carpathians at a time interval that envelops Late-Hercynian and Alpine events is substantiated. Moreover, this concerns the Outer Carpathians, but the whole Carpathians arch was characterized without going into details, a critical estimate is expressed for application of such terms as terrains, accretion prism, suture, subduction and Transcarpathian fault. It is shown that formation of the Carpathians occurred through several stages under the influence of different-directed, manly horizontal, movements, as a result of which was destruction of early formed Hercynian continental crust, laying of geosynclinals troughs, formation and further transformation of the basement of the Flysch Carpathians, its collision with Eurasian continental edge, underling of the latter under flysh complex. After completion of these processes mainly vertical movements took place that lineally formed the structure of the Carpathians as folded-covering-block one. As a result of the last event (Pliocene-Pleistocene), a differential development of intensive fracturing occurred with the influx of hydrocarbons and filling traps formed up.

The paper gives a critical appreciation of a number of principles containing in materials of the State geological map at a scale of 1 : 200 000 (Carpathian series of sheets) published in 2003–2009. Its scientific and practical value is recognized as a source of knowledge of the structure and natural resources of the Carpathians. At the same time, numerous inaccuracies are noted in the sphere of stratigraphy and tectonics, but revealed in the reviewed work. This was negatively depicted on the quality of geological and tectonical maps of the Folded Carpathians, presented in it, that in its turn may have an influence on the appreciation of the prospects of oil and gas presence in the region, may be not for the best. On the basis of the analysis of considerable amount of factual material, including that one received after the publication of State geological map – 200, the authors have corrected revealed defects. The attention was paid to the possibility to create the latest, more perfect map of the Outer Carpathians at a scale of 1 : 100 000. Its base version is already existent.

We have studied the Cretaceous and Paleogene flysch of the Duklya-Chornohora, Burkut, Rakhiv, Marmarosh and Pieniny covers that in the south-eastern sector of the Ukrainian Carpathians near the Romanian border (Hutsulian segment) distinguish themselves by very inclined overthrust. Spatially the given tectonic units are in so-called hydrothermal fluid, unfavourable on the whole as to the presence of hydrocarbons in it on a large scale. But, within its limits the plots, small in area, with hydrocarbon prevalence in the gas composition are distinguished. Prospects for gas presence in the region should be connected with those of them that spatially are drown to the Transcarpathian trough. One such section is the Velikobychkovk sector of the Monastyretsky sub-cover, where it is proposed to lay a parametric well 1-Velikiy Bychkov, in order to reveal the possible para-autochthon of the Vezhany sub-cover and the Paleogene of the Dilovetsky sub-cover. In addition, according to seismic data, a significant rise in the pre-flysch base is forecast in this section of the Carpathians under the Marmarosh cover. The roof of this foundation at the location of the recommended well 1-Velikiy Bychkov may be at a depth of 5000–5500 m. It may be represented by the youngest deposits of the pre-Alpine complex – the Triassic strata, industrially oil and gas saturated in the neighboring countries.

In the south-western part of the Krosno cover in the terrain of the Ukraine, that is called jednostka Szląska (Silesia Unit) in the adjoining Polish territory, two tectonic structures Tykhiy and Vetlina composed of flysh of the Cretaceous-Paleogene age, are correspondingly present. They are in the same scale and represent preserved anticlinal fold of the north-western strike. The Tykhiy and Vetlina structures were defined according to results of drilling. In consequence of executed drilling works the commercial gas presence of both structures was determined. Maximum gas discharges from the deposits of Oligocene at both structures are estimated to be approximately 60th m3/day. The production reserves of the Vetlina structure are estimated at 73 million m3 of gas. The deposit is not being developed due to localization in the area within the Beskydy National Park. The authors don’t recommend to carry out exploratory drilling within the limits of the structure, in located further north-east of the Tykhiy structure the Volosianka–Pidpolozzia and Husne–Bukovets scales as the ineffective drilling because of the absence of perspective objects in their composition. There are prerequisites to suppose the presence of just one more gas-saturated fold, Liuta, further south-west of the Tykhiy structure, under the Duklya–Chornohora cover. It is located within the hydrocarbon field, favourable for the search for hydrocarbons. The potential industrial gas potential of the forecasted promising structure is evidenced by the inflows of oil and gas in the mapping wells of Liuta Square. Significant manifestations of hydrocarbons were observed in well 18-Liuta. From a depth of 40 m, and then 190 m recorded oil manifestations – oil films on the surface of the clay solution (d 20 – 0.843 g/cm3; viscosity in 0E – 1.92; S – 0.22 %, the beginning of boiling – 97 °C, up to 350 °C – 56 %). Intense gas manifestations were noted from a depth of 167 m (CH4 – 95.36 %; CO2 – 1.01 %; N2 – 3.63 %). To check this supposition, it is expedient to conduct seismic survey.