旋冲螺杆钻具在硬岩地热钻探中的应用研究

Application study of rotary-percussive screw drilling tool in hard-rock geothermal drilling

摘要:

针对目前地热钻探中，在花岗岩、片麻岩等硬岩地层中机械钻速低的问题，引入一种机械式旋冲螺杆钻具，先后在JHR-1井花岗岩地层及HG-1井片麻岩地层中进行了试验应用。与普通螺杆钻具相比，旋冲螺杆钻具在JHR-1井?215.9 mm井段、HG-1井?215.9 mm井段和?311.2 mm井段机械钻速分别提高了10%、8.4%和7.6%，同时，旋冲螺杆钻具使用过程中未产生其他副作用。试验证明使用旋冲螺杆钻具可以有效地提高花岗岩、片麻岩等硬岩地层的机械钻速，为旋冲螺杆钻具在硬岩地层地热钻探中的应用推广打下了基础。

Abstract:

In view of the problem of low mechanical drilling speed in the hard rock such as granite and gneiss in the geothermal drilling at present， a mechanical rotary-percussive screw drilling tool is introduced and tested in granite formation of JHR-1 well and gneiss formation of HG-1 well. Compared with the ordinary screw drilling tool， the mechanical drilling speed of the rotary-percussive screw drilling tool increases respectively by 10%， 8.4% and 7.6% in ?215.9 mm well section of JHR-1， ?215.9 mm and ?311.2mm well section of HG-1， and no other side effects exist during the drilling process. The test proves that the mechanical drilling speed can be effectively improved by the use of rotary-percussive screw drilling tool， which provides a foundation for the application and popularization of the rotary-percussive screw drilling tool in the drilling of hard rock such as granite and gneiss.