oil field in Shandong (Shantung) province, China, one of the country's major sources of petroleum. Consisting of about 40 small fields, it is located southeast of Beijing, near the Bo Hai (Gulf of Chihli) and south of the mouth of the Huang He (Yellow River). Teams, brought in from the Daqing oil field in Helongjiang (Heilungkiang) province, began drilling in 1964 near the village of Shengli. The field began to produce petroleum in 1966, and by the 1970s its output had been expanded considerably. An oil refinery subsequently was built, as was a pipeline about 700 miles (1,100 km) long (completed in 1979) that connected the Shengli and nearby Renqin oil fields with Nanjing (Nanking) to the southeast on the Yangtze River (Chang Jiang). Annual crude oil production at Shengli reached a peak of roughly 30 million tons in the early 1990s and thereafter declined.