Sandy collector of В-25-26 horizon, Berezivsk gas condensate field, based on core study

Abstract

The aim of this work is to study the petrographic and petrophysics methods of sandstones samples in the borehole 150 of Berezivsky deposit and compare them with sandstone of horizon B-25-26 Kotelevsky and horizon C-5 Berezivsky fields to establish the identity of their petrographic type, as well as prospects for the proliferation of this type of sandstone at lateral within adjacent structures.

Despite the proven productivity of horizon В-25-26 in Berezivsky deposit and the drilling of six exploration wells on the horizon, the actual composition, structure and properties of reservoir rock core was unknown, as neither of the horizon was supported by the core material. Only after coring in estimated operating well 150 it became possible to come to certain conclusions. In the neighboring Kotelevsky field it has been established that the collectors of this horizon are specific, virtually single mineral quartz sandstones with regeneration of quartz cement, which could keep a good capacitive-filtration properties under intensive catagenetic transformations. In the preparation of the horizon exploration projects in Berezivsky deposit it was found out that the sandstones characteristic of the Kotelevskaya Deposit can be developed here, however, it was confirmed only now.

It has been confirmed that high debit collectors of horizon В-25-26 in Berezivsky deposit are the same quartz sandstones, which form the horizon on Kotelevsky field. Where they disappear, the flow rates decrease like in the sandstones of horizon C-5 of the Berezivsky Deposit. It can be argued that these sandstones belong to a single petrographic type of rocks, fairly widespread in the lower Carboniferous. A feature of this species is atypical behavior in the catagenesis compared to the sandstones with clay cement, for which a scheme of catagenetic transformations was developed. Rocks of this type are significantly better resisant to external influences and can keep good capacitive-filtration properties at great depths.