Provincial Economy and Trade Committee approved the construction of Yulin Refinery (formerly named as Petroleum Assistant Plant of Yulin District) in 1992, which was a key project for technology reform.
Petroleum Assistant Plant of Yulin district preparation office was set up and began its operation.
Then Yan’an Refinery developed and produced 90# gasoline in 1996, and became the first refinery of Shaanxi to produce high-number gasoline.
In May 1994, on the 50th anniversary of Mao Zedong’s inscription “Immerge in hard work” for the plant director Chen Zhenxia, Premier Li Peng added one more for Yanchang Oilfield: “Immerge in hard work and make more contributions.”
In October 1996, the 150 thousand tons per year normal pressure distillation installation was built up and put into operation. In May 1997, the 70 thousand tons per year catalytic cracking installation was built up and put into operation. For more than ten years it has been developed into such a one time processing productivity with 1500 thousand tons per year of normal pressure, 800 thousand tons per year of second time heavy oil processing with catalytic installation, 1500 thousand tons per year of gasoline reforming, and 200 thousand tons per year of diesel hydrogenation auxiliary installation.
Through years of development it now reaches the real production capacity of 4500 thousand tons per year of normal pressure processing, 1600 thousand tons per year of catalytic cracking, 300 thousand tons per year of reforming, 400 thousand tons per year of diesel hydrogenation, 300 thousand tons per year of gas fractionation, 300 thousand tons per year of liquefied gas refinement, 100 thousand tons per year of aromatic hydrocarbon extraction, 100 thousand tons per year of polypropylene, and 60 thousand tons per year of MTBE.
Main products include diesel oil, gasoline, kerosene, polypropylene, benzene, toluene, xylem, and isobutyl benzene.
In 1950s, Yanchang Oilfield launched the point-wise water flooding experiment in Yongping and Qilicun oilfields, and pattern flooding experiment in Qinghuabian in 1973. In 1991 it set up a water flooding experiment team in Zichang Oilfield to experiment on single well water flooding. It also tried pilot tests in Chuankou Oil Mine in 1998. Through years of study and experiment, it established the water quality standard that suits to the water flooding of Yanchang Oilfield. Meanwhile it perfected the processing technique for fine water quality. In addition it also introduced the technique for sewage treating and reinjection, simplified the technological process of ground water injection, and thus developed the water injection technological process suited to the ultra-low permeable oil field of northern Shaanxi. It gathered a certain experience for the development of water injection of ultra-low permeable oil reservoir, on the basis of deeper understanding and dynamic research on oil reservoir. Thus, with a certain gain of water injection effect, it gradually amplified the reservoir energy and slowed down the propensity of the rapidly decreasing productivity of oil wells. The technology was then spread all over.
On February 4, 1999 Shaanxi Yanchang Petroleum Industrial Group Co. began operation in Yan’an.
Chinese petroleum industry began a great restructuring in 1998. To meet the new situation, the provincial Party committee and provincial government integrated the former Yanchang Oilfield Administration Bureau attached to Yan’an city, Yanlian Industrial Group Company, and the former Yulin Refinery attached to Yulin district, to set up an exclusive state owned enterprise and to lay the foundation for the sustained and scientific petroleum development in northern Shaanxi.
The first horizontal well of Yanchang Oilfield is located south of Bianqiao village in Chuankou, Yan’an.