China Petroleum & Chemical Corp (Sinopec), the nation's largest refiner, plans to raise its output of natural gas in the second half of this year, Chairman Wang Yupu said Thursday.

Wang said the added natural gas will mainly be sourced from its shale gas fields in Southwest China's Sichuan Province and Northwest China's Xinjiang Uyghur Autonomous Region, news portal cnstock.com reported Thursday.

The company closed some low output oil fields in the first half amid the sharp decline in international crude prices, according to Wang.

Sinopec posted a 22 percent year-on-year drop in its profit in the first half of 2015 because of falling crude prices, according to its interim report released Wednesday.