Abstract: Water based foams have been widely used in oil well drilling，foam flooding，mineral flotation and other fields.
Because of the complexity and instability of their own structure，the exact description of their rheological properties should
consider various factors such as liquid film drainage，gas diffusion，foam mass and structure，foam compressibility，wall slip，
bubble size compared with measuring system，environment temperature and pressure and so on. This leads to no generally
accepted theory for their rheological behavior. A widely available method of controlling the wall slip is to increase surface
roughness of the flow channels such as rotor surface or pipe wall during the experimental investigation，and some theoretical
modification methods deduced from some appropriate hypotheses have a better adaptability. The volume equalized constitutive
equation assumes that the friction factor of foam flow in pipe is a constant，which can solve the difficulty of its pressure drop
calculation due to the foam compressibility to some extent. It is widely believed that the foam rheological properties can be
satisfactorily described by power law or Herschel-Bulkley models，but the existence of“yield stress”for the aqueous foams is
being disputed due to different measurement conditions.

Key words: water based foam, rheological behavior, wall slip, slip correction, compressibility