天然气指数盘中涨2%，多股涨超8%

Group 1 - The natural gas index increased by 2% during the trading session [1] - Among the constituent stocks, Tongyuan Petroleum surged by 15% [1] - PetroChina Oilfield Services reached the daily limit up [1] - Potential Energy Holdings rose by 9% [1] - Zhongman Petroleum and China Oil Engineering both increased by over 8% [1]