Method and device for identifying fluid property of dense formation

The invention discloses a method and device for identifying the fluid property of a dense formation. The method comprises the steps that a preset fracture aspect ratio, preset fracture density and preset gas saturation are obtained, first rock porosity and the bulk modulus and shear modulus of a rock matrix are obtained, and the fracture density and the gas saturation are changed according to a preset strategy; a parameter group is established according to the fracture density and the gas saturation after each change; each parameter group is processed as follows: a longitudinal wave speed and a transverse wave speed are calculated according to the bulk modulus and the shear modulus of the rock matrix, the first rock porosity, a preset fracture aspect ratio and the parameter group by utilizing a pore and fracture-containing medium elastic fluctuation unified theory model; a relation curve graph of the longitudinal-transverse wave velocity ratio and the longitudinal wave slowness is drawn according to the longi