Fluid recognition in the south Ordos Basin using seismic data encounters two challenges:one is the tight reservoir

the physical properties of which are not clear

and thus the rock physical parameters that are sensitive to oil-bearing are unknown;the other is that the quality of seismic data is relatively poor

which can hardly satisfy the need of elastic parameter inversion.Hence

this study proposed methods and procedures that can overcome these challenges in rock physical modeling

seismic data processing and inversion.Regarding the complex mineralogy compositions of tight oil reservoirs in the South Ordos Basin

we proposed a way of constructing an anisotropic rock physical model.And on the basis of modeling and rock physical analysis

we identified that the ratio of Lame's coefficient and shear modulus are sensitive to oil-bearing in strata.Given the low signal-to-noise ratio in the south Ordos Basin

we introduced some solutions for certain key parts of data processing

including multi-scale static correction

amplitude consistency correction

angle gather correction

and simultaneous inversion of elastic parameters

and got reliable results for elastic parameter inversion.In combining the sensitivity parameters and results of elastic parameter inversion after rock physical analysis

we predicted the oil-bearing property of Chang 7 Member of certain exploration area in the south Ordos Basin

and the prediction matched well with the actual drilling results.The associated methods and region-specific solutions are efficient in practical application

and thus to certain extent

the technical difficulties in seismic fluid recognition for tight oil reservoirs in the South Ordos Basin with low signal-to-noise ratio are solved.