Prospects for the gas and condensate production from the South Hrabyne zone of the Precarpathian foredeep

Abstract

The main problems of prospecting and exploration of gas and gas condensate fields in the lithological and stratigraphic strata of the southwestern and central parts of the Bilche-Volytsia zone are due to the complex tectonic and lithological and stratigraphic conditions for the hydrocarbon deposits formation. The objective factors include the complex geological structure of reservoir rocks due to tectonic disturbances in the process of trap formation, the presence of various types of voids and clay material, as well as flooding of productive formations at the final stage of development. In addition, it is necessary to note the decrease in the information content and efficiency of both ground and borehole electrical exploration. At the same time, lithotypes with a complex petrographic and petrophysical thin layer structure of the rock matrix are observed in the Neogene deposits. Thus, in order to increase the information content of the results of geophysical well surveys (GWS) and the efficiency of hydrocarbon prospecting, it is necessary to form an optimal set of the latest geophysical methods, in particular: high-frequency induction logging with isoparametric sounding (HFILIS), nuclear magnetic logging (NML), as well as acoustic and radioactive studies. The introduction of this type of innovation will increase the information content of geological and geophysical studies. The main basis of this approach is the petrographic and petrophysical base for specific territories and prospecting areas. In view of the foregoing, we identified gas-saturated reservoir rocks, established the structure of their seal rocks, as well as determined the effective thicknesses of rocks and developed correlation schemes for their distribution within the Sarmatian, Badenian, and Helvetian deposits.