In 1971 Yanchang Oilfield experimented on small charge burst point and selective hydraulic fracture in Yanchang and got remarkable results. It turned the previous burst inefficacious areas and inefficacious oil reservoirs into high production areas. Thus Yanchang Oilfield reappraised and enhanced the oil reservoir fracturing experiment, and in 1973 created another novel technique called literal: self extricating reversed buckle pipe, which enhanced the fracture efficiency. Hence hydraulic fracture was widely spread over the plant.
In 1974 Yanchang Oilfield succeeded in the experiment of hydraulic sanded fracture. In 1991 it began another experiment on gelling fluid fracture technology, and began spreading all over the Bureau after the break through in 1998. Technologies such as gelling fluid fracture are among the chief productive manners of Yanchang Oilfield Administration Bureau at present.