长距离上向瓦斯压力测试钻孔逐级注浆封孔技术

Study on long distance upward sectional grouting borehole sealing technology of gas pressure test borehole

为了解决穿层长距离上向瓦斯测压钻孔在封孔过程中,封孔材料在重力作用下,传统的封孔工艺孔口堵头易被挤出钻孔,难以形成测压室,而无法真实准确测定煤层瓦斯压力的难题。结合平煤六矿实际煤层赋存条件,提出采用穿层长距离上向测压钻孔逐级注浆封孔技术,并在戊8-22310工作面进行应用,结果表明:采用传统封孔工艺的1—3号测压孔均封孔失败,且造成钻孔的报废。采用逐级注浆封孔技术,不仅解决了传统注浆封孔工艺无法在长距离上向测压钻孔上应用等难题,而且封孔测压成功率高,测定的最大瓦斯压力分别为4号测压孔0.73 MPa、5号测压孔0.96 MPa、6号测压孔0.89 MPa,比较接近实际瓦斯压力1.03 MPa;由于测压室距采面的距离不同,测压孔反映的卸压效果及各时期维持的时间也不相同。

In order to solve the difficult problems to form gas pressure measuring chamber and to real and accurately measure the seam gas pressure due to a plug easily extruded from the month of the borehole with the traditional borehole sealing technology applied,under the gravity role of the borehole sealing material during the borehole sealing process of the passing through strata and long distance upward pressure measuring borehole,in combination with the actual seam deposition condition in No. 6 Mine of Pingdingshan Coal Mining Corporation Limited,a sectional grouting borehole sealing technology of the passing through strata long distance upward pressure measuring borehole was provided and was applied to E8-22310 coal mining face. The results showed that with the application of the traditional borehole sealing technology,the borehole sealing of No. 1-3 pressure measuring boreholes was all failure and the boreholes were abandoned. The application of the sectional grouting borehole sealing technology could not only solve the traditional grouting borehole sealing technology hard to be applied to the long distance and upward pressure measuring borehole and other difficult problems,but could have a high efficiency in the borehole sealing and the pressure measurement. Each measured gas pressure value would individually be a max value of 0. 73 MPa from No. 4 pressure measuring borehole,0. 96 MPa from No. 5 borehole,0. 89 MPa from No. 6 borehole and was closed to the actual gas pressure1. 03 MPa. Due to the pressure measuring chamber with different distances to the coal mining face,the pressure released effect and each period keeping time of the pressure measuring borehole would be different.