Water-jet drilling technology is one of the stimulation technologies developed rapidly with the trend of low-cost recovery of remaining petroleum. The system is made up of 4parts,high-pressure water-jet power system,casing-exit tools,CT pulling/running system,and jet nozzles for reservoirs downhole. By analysis made on the lateral drilling length,the lateral hole number,the hole diameter,permeability the longitudinallateral ratio,and the thickness of the formation,the design ranges of the 5 main parameters of the productivity parameters were defined for optimum productivity ratio. In October 2010,this technology was successfully applied in the carbonate reservoir,and later in sandstones,granites and other lithology,a significant increase in oil production was observed. With the technology matured and experience accumulated,combined with steam huff-and-puff and high-pressure water jet theory,this technology has been further applied in the development of remaining petroleum. It will be widely used at Liaohe and other oilfields in China.