Ultra-High-Pressure Hydraulic Slitting Pressure Relief and Penetration Enhancement Technology and Equipment for Soft Coal Seams

Table 1

Calculation results of kerf drilling radius.

Cumulative extraction days	Single hole (average) cumulative total drainage (m^3)	Number of holes to be drilled (pcs)	Drainage radius (m)
30	880.23	51.04	2.47
60	1352.92	33.21	3.07
90	1943.50	23.12	3.67
120	2559.15	17.56	4.21
150	2963.52	15.16	4.54
180	3256.40	13.80	4.76