On September 19, the oil production plant No. 3 of Huabei Oilfield, which had been shut down for more than 4 years due to high water cut, opened the well with ultra-short radius horizontal well technology, and the daily oil production reached 11 tons, which has been stable for 48 consecutive days. In Huabei Oilfield, ultra-short radius horizontal well technology is used to excavate the remaining oil at the far end of potential high aquifer, which gives a new life to the closed well and provides a new idea for the late development of high water cut old oilfield.

Liu23-1 well is a long stop well in Suning-Dawangzhuang "ballast stone" engineering block. In order to further tap the potential of remaining oil, development technicians changed their development ideas and firmly established the development concept of "remaining oil is prevalent". Under the guidance of the "five-weight" technical route of the "ballast stone" project, they re-carried out reservoir evaluation, finely delineated reservoir units, accurately quantified remaining oil, and found that there were still remaining oil in the high structural part of the formation of Liu23-1 well.

After in-depth research and repeated demonstration by technical personnel, combined with the research results of remaining oil, technical personnel of Huabei Oilfield determined to introduce ultra-short radius horizontal well technology in Liu23-1 well to carry out tests. This technology uses flexible drilling tools and trajectory control technology to tap the remaining oil at the far end of the original wellbore, which has the advantages of "small curvature radius, high sweep volume, simple deviation process, short well construction period and low cost".

During the implementation process, the technicians accurately controlled the well trajectory, optimized the horizontal section length, and accurately calculated the perforation position, and successfully completed the ultra-short radius horizontal well measure of 151 meters under the premise of high efficiency and safety. At present, the well has accumulated 375 tons of oil since the beginning of August, and it is revitalized.