Romania's biggest gas producer Romgaz does not plan to tap shale gas exploration in the next few years, but will invest heavily in conventional wells using its existing financial resources, it said on Tuesday. "We always stressed our base activity is conventional exploration, there are many things to do here, on the other hand as a perspective, it would be good to find out non-conventional potential," Romgaz's General Director, Virgil Metea, told the Reuters East European Investment Summit.