PJSC “Mining Company "Ukrnaftoburinnya" is one of the leading private companies in Ukraine engaged in the production of gas and liquid hydrocarbons. By the production volume, UNB is the second among private oil and gas production companies in Ukraine.

Since 2010, UNB has been actively engaged in the development of the Sakhalin oil and gas condensate field, which is classified as a medium-size field with a complex geological structure, located in Bohodukhiv region of Kharkiv Oblast (northern near edge zone of the Dnieper-Donets Rift).

As of the end of 2021, UNB operated 32 gas condensate and oil and gas wells with a depth of 3,800 to 5,750 m and 10 additional gas condensate wells under the terms of the joint activity agreements.


The company is implementing a large-scale program for the development of the Sakhalin field: in total, for the period from 2010 to 2021, the capital investments amounted to more than 5.6 billion hryvnias, 18 new wells were drilled, 46 wells were overhauled, and gas production at the Sakhalin field amounted to more than 5.5 billion m3). As a result, UNB has one of the highest reserve-to-production ratios in Ukraine.

Total for the period 1981 - 2021


The Sakhalin oil and gas condensate field is in the territory of the Bohodukhiv region of Kharkiv Oblast.

Tectonically, the Sakhalin field is in the northern edge part of the Dnieper-Donets Rift and is associated with the line of northwest folds of the Vysokopillia basement high.

In terms of workable hydrocarbon reserves, the Sakhalin deposit is classified as the small, and, in terms of the geological structure complexity, the hydrocarbon phases, the conditions of occurrence and the variability of properties of the productive pool, it is classified as the very complex one.

The field was opened in 1981 by well #4, where the commercial oil flow from the M-2a horizon was received. In the same year, the gas flow from the C-5 horizon was received from well 8.

The depth of hydrocarbon deposits ranges from 3,300 to 6,000 m, which significantly complicates all production processes of reserve development.


The development of the field began in 1984.

The peak of hydrocarbon production was in 2019. This year, natural gas production is 862 million cubic meters.

As of the end of 2021, the total number of producing wells was 32 units.


UNB received a special permit for the use of subsoil of the Sakhalin field and began commercial development.


As a result of workovers of 12 wells, UNB increased production volumes of natural gas by 80%, and volumes of oil by 45%. The volumes of hydrocarbon production of the Sakhalin deposit, including the implemented joint activity projects, increased by 3 times.


The company drilled 2 new deep wells and carried out workovers of 2 wells, and, as a result, the hydrocarbon production increased by 20%.

Number of wells at the end of 2014: 9 gas and 7 oil wells.

Reserve-to-production ratio: 20 years.


As a result of the commissioning of a new gas condensate well, UNB increased the natural gas production by 40%. The hydrocarbon production of the Sakhalin field increased by 35%, including the implemented joint projects. The company carried out a 3D seismic survey of the Sakhalin field to assess its potential.

The inhibitor-methanol facility was modified and expanded, and the oil and condensate processing line was upgraded.


As a result of drilling 3 new gas wells and workovers of 4 gas wells, the production growth in 2016 amounted to 66%. The company began active development of commercial operations, and the monthly volume of gas sales increased 3 times, namely from 20 to 60 million cubic meters.

The geological and technical team of UNB is strengthened by specialists with international experience.


Two new wells were completed and drilling of two more wells was started, and their completion was planned for 2018. Also, workovers of 7 wells were done.


4 wells drilled

3 well workovers were carried

Own pipeline commissioned.


Additional gas separation line was built and the capacity of OGP facilities was increased

3 wells were drilled

Drilling of 2 wells was ongoing

7 workovers of wells

Additional 3D seismic survey.


State-of-art propane cooling unit was put into operation

Modernization of the liquid hydrocarbon processing line was ongoing 

2 workovers of wells

Number of wells: 23 gas wells and 9 oil wells.

Number of wells at the end of 2020: 23 gas wells and 9 oil wells.

Reserve-to-production ratio: 6 years.


UNB resumed the drilling program after the industry crisis in 2020.

During 2021, the company developed 1 new well and carried out workovers of 9 wells.

One of the wells was converted from the gas lift method to the pump lift method of operation with setting the bottom-hole pump (BHP) at 3,251m depth, which is the biggest BHP running depth in Ukraine.

The implementation of a large investment project for the construction of the boosting compressor station, to the value of about 0.5 billion hryvnias, has begun at the Sakhalin field.

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