Regal said audited results from the year ending Dec. 31 revealed a production rate of barely 7,000 cubic feet per day.
The company added that it posted a profit from continued operations of $13 million, a $3.3 million loss from 2011.
Ukraine is struggling to improve its image as a natural gas transit area following disagreements with Russian gas monopoly Gazprom. Ukraine hasn't been able to secure financial support to revamp its gas transit system but is reviewing gas deposits, particularly shale gas reserves, in the interim.
Regal said this month that reserves were lower than expected from its Mekhediviska-Golotvshinska and Svyrydivske gas and condensate fields in Ukraine.
A third-party assessment found a "material reduction" in proved and proved-plus-probable reserves at the company's natural gas fields.
Nevertheless, the company said its outlook for the year included "continued development of Ukrainian assets through new wells, workovers and compression installation."
The Ukrainian government expects there may be enough natural gas in shale plays to meet the country's needs without imports.