Research on the Coal Seam Permeability-Increasing Technology via High-Pressure Water Jet Reaming and Its Application

Table 3

Investigation table of unreamed conventional borehole drainage data.

Time (d)	Concentration (%)	Negative pressure (kPa)	Mixing amount (m^3/min)	Flow (m^3/min)	Daily discharge of single hole (m^3/d)
1	62	15	0.34	0.21	50.74
2	61	18	0.34	0.21	49.30
3	60	18.8	0.34	0.20	48.69
4	59	19.1	0.34	0.20	47.59
5	55	19	0.35	0.19	45.94
6	53	18	0.33	0.17	41.71
7	51	17	0.31	0.16	38.51
8	48	16.9	0.32	0.15	36.92
9	46	16.8	0.33	0.15	36.55
10	46	16.8	0.30	0.14	33.41
11	44	16.9	0.28	0.12	29.92
12	44	16.6	0.27	0.12	28.19
13	42	17	0.27	0.11	27.53
14	41	16.5	0.25	0.10	24.35
15	39	16.6	0.23	0.09	21.26
16	38	18	0.20	0.08	18.57
17	36	18.2	0.19	0.07	16.73
18	35	18.5	0.18	0.06	15.27
19	33	18.8	0.18	0.06	14.12
10	32	18.9	0.18	0.06	13.71
21	31	17.5	0.17	0.05	12.99
22	30	17.6	0.18	0.05	12.71
23	29	17.7	0.17	0.05	11.72
24	27	15	0.17	0.05	11.16
25	26	14.8	0.16	0.04	10.29
26	24	15.2	0.17	0.04	9.63
27	22	14.6	0.16	0.03	8.32
28	20	14.5	0.16	0.03	7.59
29	19	14.4	0.14	0.03	6.35
30	19	14.3	0.14	0.03	6.35