The Research Of Sandstone Seismic Property

Sandstone is the most common reservoir rocks.The research about sandstone's physical nature has an important significance in the oil and gas exploration.Sandstone research focus on the porosity,permeability,etc before.The precise measurement of the seismic wave velocity in the laboratory for sandstone research is less.In this paper,the study of seismic properties of sandstone,can for the interpretation of the seismic data in the oil and gas exploration and provide the corresponding constraints for logging data comparison and reference.The experiment main analysis the sandstone's seismic wave velocity under different pressure with the change rule of water saturation;and combine wave velocity pressure and water saturation,draw the relation between the three dimensional figure.According to the previous seismic properties of the model is set up,calculate four group sandstones' wave velocity,compare with the measure value and get the conclusion.Analyze anisotropic characteristics of sandstone under the different fluid condition.Through the study found:(1)The sandstone of Hami area,seismic velocity changing with pressure has a strong logarithmic relationship,the correlation coefficient over 0.96.(2)The sandstone of Hami area,p-wave velocity increases with the increase of water saturation,with the increase of pressure,this increase speed slowed.Shear wave velocity in low pressure is not affected by the fluid saturation,but with the increase of pressure,shear wave velocity with the increase of water saturation,trend significantly smaller;Simply by seismic wave velocity is difficult to distinguish pore internal oil and water,need more other data;(3)The existing model calculate sandstone theory wave velocity compare with the measured values,the error is larger under low pressure,and smaller under high pressure Theoretical modes are not fit well for complicate pore structure and high content of clay sandstone.(4)The anisotropy of the sandstone in Hami area is not very large,with the increase of pressure the anisotropy has a trend of decreasing.The dry saturation,oil saturation and water saturation has a obvious anisotropy difference under every pressure.The anisotropy value is dry saturation > oil saturation > water saturation,this discovery can be used as the region of oil and water layers and oil and gas layer.