Experiment study and application of point hydraulic fracturing device

In order to improve the seam permeability and the gas drainage effect, a point hydraulic fracturing technology was applied to improve the permeability of the mining seam. The paper introduced the action principle of the point hydraulic fracturing device. The rational technical parameters of the fracturing device were deter mined by the lab experiment. An industrial test was conducted in Panbei Mine. The applied statistical results of the geostress showed that the initial fracturing pressure of the test seam was 23.6 MPa and 23.0 MPa individually. The industrial test showed that after the seam fractured, the average gas drainage flow of the fractured group was 2.5 ~ 3.5 times of the conventional gas drainage group and the average gas concentration was 1.9 ~ 2.5 times of the conventional gas drainage group. The point h ydraulic fracturing and permeability improved technology could have a good permeability improved effect in the low permeability seam. The fracturing time of the techno logy was short. The technology could highly improve the emission volume and drainage volume of the seam gas, could effectively improve the seam gas production and would have a wide prospect of the application to improve the seam permeability.