REUTERS National Joint-Stock Company Naftogaz of Ukraine says the country boosted natural gas stocks in its underground storage facilities (USFs) by 4.4 billion cubic meters (bcm) as of October 13, 2019, to 21 bcm from October 13, 2018, having reached a record high natural gas stock over the past 10 years. "Ukraine has increased gas volumes in its underground storage facilities (USFs) to 21 bcm, which is 4.4 bcm up from last year&#39;s figure on the same date. Such gas reserves in storage facilities are record high over the past 10 years. They ensure a smooth heating season. Gas injection into the USFs is under way," the Naftogaz press service said on October 15. According to Naftogas, Ukraine needs to accumulate at least 20 bcm of gas in its USFs to pass the forthcoming heating season. Read alsoUkraine hopes for successful gas transit talks, but prepares for worst-case scenario – Gerus As UNIAN reported earlier, Ukraine on April 5 started the season of pumping natural gas into its underground storage facilities. By the start of the 2018-2019 heating season, Ukraine had accumulated 17.2 bcm of gas in its underground storage facilities, which was a record high natural gas stock over the past six years. UNIAN memo. Ukrtransgaz operates 12 underground gas storages (USFs) with a total storage capacity of about 31 bcm. The USFs are an integral part of Ukraine&#39;s gas supply system and gas transit through its territory. The company is also the operator of trunk gas pipelines carrying gas from Russia to the EU. Ukrtransgaz is wholly owned by NJSC Naftogaz of Ukraine.