The invention relates to a preparation method of a
coal-series reservoir group fracturing
object model sample taking a transition zone into account. The preparation method includes the steps: uniformly mixing
cement and
quartz sand according to a certain proportion, adding water, stirring the
cement, the
quartz sand and the water to form
cement slurry, and pouring the
cement slurry to the bottom of a sample mould to form a rock layer of a
coal-series reservoir group; uniformly mixing the cement, the
quartz sand and pulverized
coal according to a certain proportion, adding water, stirring the cement, the quartz sand, the pulverized coal and the water to form coal-bearing
slurry, preparing at least ten parts of coal-bearing
slurry containing different proportions of pulverized coal, pouringthe coal-bearing slurry to an intermediate layer of the sample mould layer by layer according to the sequence from small proportions of the pulverized coal to large proportions of the pulverized coalto form the transition zone of the coal-series reservoir group; uniformly mixing the cement, the quartz sand and the pulverized coal according to a certain proportion, adding water, stirring the cement, the quartz sand, the pulverized coal and the water to form coal-bearing slurry, pouring the coal-bearing slurry to the top of the sample mould and inserting a plurality of mutually perpendicular paraffin slices to form a coal and rock layer of the coal-series reservoir group. The
mechanical property of the
object model sample prepared by the method is infinitely close to that of the real coal-series reservoir group.