1. Introduction
Tangjiahui Coal Mine’s geological conditions are complex, with well-developed structures in the working face. The Ordovician water beneath the 6th coal is likely to threaten the safety of the mine through faults, collapsed columns, fissures and other water channels. Directional long drilling in floor is used to identify floor partitions and hydrological anomalies within the water layer. Borehole drilling needs to pass through weak layers such as floor mudstone, 9# soft coal seam and occasionally encounter small faults, broken zones, etc, which bring relatively drilling difficulty.
2. Solution
In view of the existence of multiple soft layers in the 6# coal seam floor, the method of casing into the stable base rock below 9# coal seam was used during the construction process to ensure drilling safety of drilling. Composite drilling technique was adopted when encountered with faults and broken zones. Grouting in the hole to reinforce faults and broken zones is also used to improve the borehole stably and drilling efficiency.
3. Construction situation
Since 2013, CCTEG Xi’an Research has successfully constructed directional long boreholes in 10 working faces of Tangjiahui Coal Mine (61101, 61102, 61103, 61201, 61202, 61207, 61208, 61302, 61303, 61304). Accumulated drilling footage has exceeded 100,000 meter. At the same time, the successful experience has been extended to other mines in the area.
4. Achieved accomplishment
The project has ensured safe mining in five working faces including 61101, 61102, 61103, 61201, and 61303. During the construction process, the abnormal body in the 61103 working face was successfully processed. The geophysical anomaly area near the interconnection of 61303 working face was inspected and verified. Y6 anomaly area near the No. 10 drilling site in the gate entry of 61303 working face was detected. DF201 fault in 61202 working face was treated. Water connection channel in 61202 working face was grouted and blocked.
Hot Tags: directional drilling in roof, China, manufacturers, suppliers, factory, wholesale, price list, buy, for sale,
