Numerical analysis on hydraulic fracturing crack of coal reservoir in southern Shizhuang Block of Qinshui Basin

In order to solve the impossible directly observation problem of the crack distribution law after the coal reservoir fractured,taking the Newtonian fluid PKN m odel as a basis,with an analysis on the fracturing operation technique and coal reservoir dynamics features in the south block of Shizhuang,in combination with settling the ory of the proppant in the Newtonian mechanics,a numerical calculation was conducted on the sand packed cracks and a prediction was conducted on the fractured crack g eometric features of the coal reservoir and the proppant distribution. The study showed that with the crack length expanded,the fluid pressure drop would cause that the cra ck width steadily reduced until close and the activated hydraulic fracturing liquid would not bring the proppant to a far terminal of the crack. During the construction process, the proppant would be rapidly settled down and the sand travel length would be less than the crack length.The paper proposed that the sand holding capacity by the fractur ing liquid properly increased and the particle size and weight of the proppant reduced could increase the support length of the crack and improve the fracturing effect.