下向测压钻孔封孔技术研究

Research on sealing technique for determination of gas pressure by downward-hole drilling

目前复杂煤层赋存条件下下向钻孔测定煤层瓦斯压力普遍面临钻孔封孔效果不理想、煤层瓦斯压力测定失败、钻孔进水损坏压力表等问题。针对此,提出了一种新的测压封孔技术即联合持续增压二级封孔测压技术,阐述了该工艺的基本原理,配制了新型发泡水泥和封孔粘液,并进行了工业性试验。试验结果表明,应用该项技术能够有效地动态封堵发育中的裂隙从而实现准确快速测压。

At present, the determination of coal seam gas pressure by drilling downward in complex coal seam occurrence condition is generally faced with problems such as unsatisfactory drilling hole sealing , failure of coal seam gas pressure determination and even damage of pressure gauge due to water in borehole .In this paper , a new pres-sure hole sealing technologya combined supercharging secondary pore pressure sealing technology was put forward , the basic principle of the process was expounded , a new type of foamed cement and sealing hole mucus were then prepared and the industrial test was carried out .Results showed that the new technology can dynamically fix developing fracture effectively so as to realize rapid determination of coal seam gas pressure .