Water injection in China: waterflooding the oil reservoirs of China

After the discovery and development of Daqing oil field in 1960, China achieved basic self-sufficiency in petroleum for domestic use by the end of 1963, and has produced over 100 million tons annually since 1978. To meet national economic needs, exploration for oil and gas and efforts to stabilize production from existing fields have been greatly expanded. Waterflooding is the dominant oil recovery technology in China at present, and 93% of its oil output is produced from fields under flood. Most of the oil fields are located in Mesozoic-Cenozoic continental basins with geologic characteristics different from those of marine basins. A set of separate-zone production technologies with associated theories has been developed in these oil fields and been widely and successfully applied. During the water injection operations, continuous reservoir study, recognition of the distribution of oil and water in different types of oil reservoirs, improvement of development systems, and increases in both sweep and displacement efficiencies of the injected water are essential to maximize recovery.