China Petroleum & Chemical Corp.'s (SNP) largest oil field by output, produced 6.83 million metric tons, or 550,000 barrels a day, of crude oil in the first quarter, up 1.4 percent compared with January-March last year, the company said Wednesday.

Sinopec Corp., as the company is known, is targeting 27.5 million tons, or 551,000 barrels a day, at Shengli, which is located in Shandong province, in 2012. It has been upgrading its older fields since the beginning of the year, it said in its in-house newsletter.

In 2011, Shengli produced 27.34 million tons of crude, or 549,000 barrels a day, the state-controlled Xinhua news agency reported previously.

Sinopec, China's largest refiner by capacity, produced 321.73 million barrels of crude in 2011, down 1.9% on year. It set an output target of 326.52 million barrels in 2012, according to the company's annual report.

China's new discoveries are barely keeping pace with output lost due to aging oil fields, limiting output growth opportunities.

China produced around 4.09 million barrels a day of crude in 2011, up just 0.3% on year, data from the National Bureau of Statistics show.