China's oil refinery throughput rose 8.2 percent in May from a year earlier, but was off April's highs as state-run plants began regular maintenance and some independents cut output ahead of a regional summit in a bid to reduce industrial pollution.
May throughput came in at 50.66 million tonnes, according to data released by the National Statistical Bureau on Thursday. That was equivalent to 11.93 million barrels per day (bpd), below April's 12.06 million bpd, the second-highest on record.
Production in the first five months of the year totalled 249.78 million tonnes, up 8.9 percent from the same period a year ago, the bureau said. State refiners enjoyed healthy operating margins during the period while independents benefited from higher import quotas.
Sinopec's Shanghai and Yangzi refineries, as well as PetroChina's Dalian and Jilin refineries, were scheduled for regular large-scale repair work between April and May.
Meanwhile, at least five independent plants in the eastern province of Shandong were ordered to cut operating rates ahead of last weekend's Shanghai Cooperation Organization summit in Qingdao.
May's domestic crude oil production fell 1.6 percent from the same month a year ago to 15.97 million tonnes, or 3.76 million bpd, registering the slowest year-on-year decline since early 2016. Year-to-date output was 78.23 million tonnes, down 2 percent from a year earlier.
With oil prices rebounding to near four-year highs, dominant state producers are increasing drilling including at ageing oil fields to maintain production. PetroChina plans to drill a total of 690 new wells this year at the Liaohe field in Liaoning province.
In the natural gas sector, production rose 5.9 percent last month compared with May 2017 to 12.6 billion cubic meters (bcm). Output for the year to date was 65.2 bcm, up 4.3 percent.