Research and application of high-level directional drilling holes in gas extraction lap part

Abstract

The reasonable lap of high-level directional drilling holes in adjacent drilling sites is an important link to ensure the stable extraction effect and improve the effective utilization rate of drilling holes. According to the results of the research on the mechanism of gas extraction in the high-level directional drilling holes of the roof fracture zone, by analyzing the influencing factors of the extraction effect such as the spatial position of the high-level directional drilling holes, the distribution characteristics of the roof fracture zone of the coal seam, and the drilling trajectory, the reasonable overlapping part of the borehole for successful replacement was determined, and the engineering application was carried out in Dangjiahe Coal Mine. The application shows that the overlapping length of 80-121 m borehole can meet the gas extraction effect, and the outer end of the lapping position can reduce the drilling amount of each borehole by about 40 m.

Keywords

• directional drilling extraction
• lap length
• fracture zone extraction
• drilling level
• drilling trajectory
• drilling utilization