Ukraine is hoping Chevron Corp. will invest 25 billion U.S. dollars to develop the potentially large Olesska shale gas deposit in its west, a senior energy official said Tuesday. \"This sum exceeds the amount of foreign investment that Lvov and Ivano-Frankovsk regions have attracted over the 20 years of Ukraine\'s independence,\" Volodymyr Ignashchenko, adviser to Ukraine\'s minister of ecology and natural resources, said during a visit to Ivano-Frankovsk city. The Olesska deposit stretches across Lvov and Ivano-Frankovsk regions. With estimated shale gas reserves of 0.8 trillion to 1.5 trillion cubic meters, Olesska will produce up to 10 billion cubic meters of gas annually, Ignashchenko said. Meanwhile, the project would create thousands of jobs within the next few years, he said. Ukraine, which imports about two-thirds of its gas from Russia, is seeking to diversify its gas sources. It picked Chevron as a partner to extract shale gas in Olesska through tender in May 2012.