1. Introduction
Anshan mine field is located in the southeast of Miaohagu mining area in Shaanxi Province, about 38km northwest of Fugu County. The northwest of the minefield is adjacent to Shaliang Minefield and Qinjin Coal Mine. The south is the small coal mining area and the reserved area of the southern Miaohagu mining area. The southwest is adjacent to Sandaogou minefield, and the east is Hazhen~Gushan exploration area. On the east side (160m away from the working face) of the original design 3006 working face of Sanpan District, there are two shafts with diameter of about 3m. According to the villager’s understanding, the shafts were constructed in Yongsheng Coal Mine in 2005 and was abandoned due to the inability to obtain relevant procedures. It is predicted that the depth of the two shafts is more than 257 meters and the ground elevation is 1215m. The inclination angle of the small coal mine shaft is estimated to be 6°. According to the elevation, the coal seam is 2². They are full of stagnant water, which poses a greater threat to the underground and affects the safe layout of the later coal mining.
2. Solution
Directional drilling technology is adopted to drain the water. Through directional drilling with branch construction, water accumulated in the shaft of the small coal mine was drained and potential safety hazards was eliminate efficiently.
3. Construction situation
Two main boreholes T1 and T2 and one branch hole T1-1 were constructed for the drainage project of two abandoned shafts in the third panel area of Anshan Coal Mine. The directional drilling footage was 375m.
4. Achieved accomplishment
According to the existing data provided by the mine, the location of the abandoned wellbore was calculated and combined with these geological data to design the drilling trajectory. Holes T1, T2 and T1-1 all met the design requirements, and the drilling trajectory accurately passed through the two predicted abandoned roadways. Because it is difficult to accurately predict the position and angle of the abandoned wellbore, the drilling trajectory did not encounter the abandoned wellbore.
5. FAQ
Q1: Why the boreholes did not encounter the wellbore?
A: The drilling trajectory accurately passes through the predicted positions of the two abandoned roadways, but because the orientation and angle of the abandoned wellbore are difficult to accurately predict, the drilling trajectory did not encounter the abandoned wellbore.
Hot Tags: coal mine water drainage, China, manufacturers, suppliers, factory, wholesale, price list, buy, for sale,
