Perspectives of gas production from reservoir-rocks neogene of sand-clay thicknesses of the Transcarpathian depression

Abstract

Increase in natural gas demand makes the researchers to look for special approachers solutions to finding out
discover hydrocarbon deposits in the Neogene sediments of the Transcarpathian depression.
The commercial deposits of hydrocarbons have been discovered in a lot of oil and gas bearing regions of the
world which can be in the form cap rocks. As an example of it there are oil and gas condensate deposits in
Bazhenovsk suite of Jurassic sediments of Middle Priobye in Russia, in the sand-clay Oligocene thicknesses of
Middle and Upper Magdalena basin in Columbia, in Maikop sediments of Skif platform and also in laminated
sand – clay piles of the Outer zone of the Carpathian Foredeep in Ukraine.
The main criterion of oil & gas bearing perspectives is the availability of psamit fraction differentiation, which
was called “sandiness” and figured out by determining the change of the psamit disperce scattering according to
the well cross-section on the contrary to the “sandanity” when only monolith sand layers are been studied. Domestic
and world experience of horizontal well drilling testifies that their application allows to substantially increase
technological indices of developing low-permeable reservoir-rocks in thin-layered sand-clay piles. The experimental
drilling of X-Ardanivsk and X-Bushtyno deviation wells is suggested to be carried out with the further drilling in horizontal direction at the distance of 250 – 300m from the vertical borehole with the next application
of hydrofracturing.
The results of horizontal wells operation give us the possibility to support that the technology of oil and gas
bearing areas of Ukraine can give substantial economic result. It is possible only on the basis of storing sufficient
experience and special research works.