Daqing Oil Province is located in the Songliao Plain in northeastern China, comprising 48 oil and gas fields of different scales. As the largest oil-producing area in China, Daqing's cumulative oil production has amounted to 2 billion tons, accounting for 40% of China's total onshore crude production.
On September 26, 1959, a commercial oil flow was obtained from well Songji-3 in the south of the central depression in the Songliao Basin, marking the discovery of Daqing Oilfield. In March 1960, development and productivity construction of Daqing Oilfield began. In 1976, the oilfield's annual crude production exceeded 50 million tons for the first time, making it one of the world's famous giant oilfields. It had maintained annual crude production at 50 million tons for 27 years since then.
The source bed in the Daqing Oilfield is mainly Mesozoic Cretaceous sandstone of continental facies, 900 to 1,200 meters underground. The crude oil is paraffin based, characterized by a high wax content (20%-30%), high freezing point (25 ℃-30 ℃), high viscosity (ground viscosity of 35), and a low sulphur content (less than 0.1%). At present, the oil recovery efficiency of the major fields has surpassed 50%.
In the late 1980s, most oil fields in the Daqing area entered the late stage of development with a total water cut of up to 90%. CNPC studied and practiced stratified waterflooding development, well pattern infilling and tertiary oil recovery technologies represented by polymer flooding. As a result, foam combination flooding technology was developed. Up to September 2006, Daqing Oil Province produced a total of 100 million tons of oil by using tertiary oil recovery technologies. Annual output by tertiary oil recovery exceeded 10 million tons in five consecutive years.
In 2008, a total of 40.20 million tons of crude oil were produced in Daqing Oil Province.
Qingshen Gas Field
In 2001, CNPC launched large scale exploration for natural gas in volcanic reservoirs buried at depths of 3,500 to 4,500 meters in the Songliao Basin.
In May 2002, well Xushen-1 drilled in Xujiaweizi area in the northern Songliao Basin was completed at a depth of 4,548 meters. In December 2004, a production test was launched at well Xushen-1, the discovery well of Qingshen gas field. The well's gas pressure was stabilized at 26-27MPa in the initial stage, with daily output maintained at around 200,000 cubic meters.
In 2005, natural gas in place at Qingshen Gas Field was proven to be 100 billion cubic meters. In 2006, nearly 130 billion cubic meters was added to its proven and possible reserves. The gas field now produces two million cubic meters per day.