Abstract: Nitrogen foam fracturing, a new fracturing technique be-ginning in 1970s, is especially suitable for the fracturing opera-tion of low-pressure, low permeable andwater sensitive forma-tion. The basic formulation and rheological properties of nitro-gen foam fracturing liquid have been studied in laboratory. The influence of some factors such as foam quality, concentration and type of surfactants, shearing rate, temperature and pressure on rheological properties of foam fracturing liquid has been stud-ied. Based on the laboratory tests, the foam fracturing liquid formulation suitable for Liaohe Oilfield has been put forward.Eight wells have been successfully fractured with the fracturingliquid, and the accumulative increasing oil is 1.24×104t, the successful ratio of treatment is 100%.

Key words: foam fracturing, nitrogen, rheological proper-ty, experimental data