China\'s oil industry will keep improving the circulation system to target a crude oil sales volume of 530 million tons in 2015, the official Xinhua News Agency reported Tuesday.The industry aims to sell 290 million tons of refined oil in 2015, Ministry of Commerce\'s guideline on the development of the oil circulation sector during the 2011-2015 period said, according to the report.\"China will foster diversified investment and managing bodies in the oil market to spur competition and to modernize distribution systems to enhance circulating efficiency,\" the guideline said, calling for the industry to step up efforts to reduce carbon emissions for greener growth of the world\'s biggest energy user.The ministry also said during the 2011-2015 period, China will continue efforts to make the sector\'s regulatory mechanism more scientific.