The invention provides a method and a device used for
hydrocarbon quantitative prediction and based on an unconsolidated sandstone model. The method comprises the steps of obtaining
background information of reservoir rock, according to the
background information of the reservoir rock, calculating a dried rock modulus of the constant-
cement unconsolidated sandstone model, calculating vertical and horizontal wave speeds of constant-
cement unconsolidated sandstone when water is saturated, arranging a
porosity degree and
saturation level distribution range according to the constant-
cement unconsolidated sandstone model, calculating formulas that a
shear modulus corresponding to each
porosity degree and
saturation level and the horizontal
wave speed are divided by density, building a rock physical template where a parameter that the
shear modulus is divided by the density and a parameter that the horizontal
wave speed is divided by the density are jointed, carrying out pre-stack synchronous inversion on earthquake pre-
stack trace gathering, enabling the obtained
shear modulus and the horizontal
wave speed during the inversion to be divided by the density and projected to the rock physical template where the parameter that the shear modulus is divided by the density and the parameter that the horizontal wave speed is divided by the density are jointed, calculating the
porosity degree and the
saturation level of a target reservoir by a template mapping method, and judging an oil-gas distribution condition of the target reservoir. The method and the device used for the
hydrocarbon quantitative prediction and based on the unconsolidated sandstone model improve prediction accuracy of the effective reservoir.