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

Table 2

Calculation results of the extraction radius of the slotted hole (fitting the negative exponential curve of extraction attenuation).

Cumulative extraction days	Single hole cumulative total drainage (m^3)	Number of holes to be drilled (pcs)	Drainage radius (m)
30	797.61	56.33	2.35
60	1470.22	30.56	3.19
90	2037.39	22.05	3.76
120	2515.67	17.86	4.17
150	2918.99	15.39	4.51
180	3259.09	13.79	4.76