Photo from UNIAN Natural gas reserves in Ukraine&#39;s underground storage facilities (USFs) have increased by 2.27 times, or by 9.47 billion cubic meters (bcm), to 16.9 bcm since April 9, when Ukraine started building up its gas stocks. Some 680 million cubic meters (mcm) of gas was injected into the USFs on October 1-20, 2018, according to the state-run gas transport system operator Ukrtransgaz. Natural gas reserves in Ukraine&#39;s USFs as of October 20, 2018, were estimated at 16.9 bcm, which was 0.15% down from 16.93 bcm reported as of October 20, 2017. Ukrainian gas imports on October 1-20, 2018, totaled 645 mcm, including 355.5 mcm via Slovakia, 244.5 mcm via Hungary, and 45 mcm via Poland. Domestic gas output over the period under review stood at 1.17 bcm, while gas transit shipments totaled 4.29 bcm, it said. Read alsoPM Groysman: 90% of Naftogaz profits to be returned to state budget The country&#39;s USFs were filled by 54.62% as of Saturday, September 20. As UNIAN reported, the National Joint-Stock Company Naftogaz of Ukraine earlier said that there were enough natural gas reserves in Ukrainian underground storage facilities to enter the 2018 2019 heating season. Ukraine entered 2018 with 14.7 bcm of gas in its USFs, which was the largest gas stock as of the beginning of the year in the past five years.