Research on trajectory measurement strategy while drilling based on screen lowering process

Abstract

Abstract In view of the soft coal seam drilling construction of small and medium-sized rotary drilling rigs in coal mines, the soft coal seam is usually used to support the hole wall due to the loose coal quality. The traditional wireless storage measurement trajectory instrument has a large outer diameter, which cannot realize the measurement while drilling in the drilling construction while the screen is lowered. In this paper, a reduced storage borehole trajectory measuring instrument is proposed, and the outer diameter and length of the probe tube are improved to be 20 mm and 692 mm. A fixed support structure for the probe pipe is designed, which can be applied to the drill pipe with an outer diameter of φ≥73mm, which is convenient for the measurement of the trajectory while drilling of the soft coal seam in the construction of the screen pipe. The industrial test shows that the measurement accuracy of the inclinometer is ± 0.2° in azimuth and plus or minus 0.1° in inclination, which realizes the process requirements of screen lowering without redrilling measurement.