UPDATE 4-China restarts oil line, gas wells shut on quake

(Adds restoration of power plants)

By Chen Aizhu

BEIJING, May 13 (Reuters) - China resumed operation of a major oil products pipeline on Tuesday after the previous day's earthquake forced it to briefly stop pumping, but some gas wells were shut by a government order, industry officials said.

Southwest Sichuan province, still reeling from a massive 7.9 magnitude earthquake that has so far killed nearly 12,000, produces about a fifth of China's natural gas. Operations at major refineries across China were unaffected.

The full impact of Beijing's order to shut oil and gas wells, chemical plants and coal mines in the area was not clear, but a spokesman for main operator PetroChina (0858.HK: Quote, Profile, Research), Asia's biggest oil and gas firm, said it would be "manageable and limited".

Sichuan produces some 21 percent of national natural gas but only 3,000 barrels a day of crude oil.

The quake rocked a mountainous area in Sichuan province on Monday afternoon, and officials and rescue workers were still struggling on Tuesday to reach the hardest-hit areas.

Shortly after the quake, PetroChina suspended oil flows at the 1,240-km pipeline that supplies most of the fuel to Sichuan to check for possible damages.

The pipeline, linking Lanzhou in Gansu province with Sichuan's capital Chengdu, and Chongqing region, has a capacity to pump 200,000 barrels of gasoline or diesel a day.