Shengli Oil Field

The Shengli Oil Field, whose name means Victory Field, is China's second largest after Daqing and one of the oldest. It lies in the delta of the Yellow River, where the ground is difficult: shifting soils, high temperatures, salty groundwater, and crude that comes up more than 95 per cent water. The seams are thin, some only 6 metres, and 92 per cent of the reservoir lies deeper than 1.2 kilometres, some of it going to 2.5 kilometres. It was discovered on 16 April 1961 when the Hua 8 well was drilled, and large-scale extraction began on 25 January 1964. Its existence was kept quiet for more than a decade for reasons of national security, and it was announced publicly in 1974. It is run by a Sinopec subsidiary.