PERMFILE121316

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT 39 MINE INFLOW ESTIMATES
• Media Type: D
• Archive: No

Getty Task 2 Page 26 March 1, 1983
underlying aquifer to the fracture zone and does not account for the drainage
of the fracture zone above the bottom of the Coal.
Although it is difficult to estimate the time and rate of gravity
drainage of such a fault zone, Equation 7 can be used to obtain as estimate of
the rate of drainage as a function of time. If it is assumed that the zone
can be approzimated as sn aquifer of unlimited eztent, the gravity drainage
through the ends of the zone (i.e. the fifty feet widths) can be estimated
(see Figure 9c). To perform this calcnlatioa it was assumed that the
traasmissivity of the zone was 100 sq. ft. per day and the specific yield is
0.10. Assuming that the fracture zone does not e:tead upward into the marine
shale, the valve of drawdown utilized in this calculation is equal to the
saturated thickness of the overburden aquifer or approzimately 100 feet. The
inflow length for this calculation is 100 feet.
Both calculations described above were performed for several times np to
( 720 days. The results of these calculations are presented in Table 2.
F______ _____'^ S e _____ ___ a
Table 2
Estimated Mazimum Upward Flow Through Fracture Zoae
Time Since
Penetration
of Zoae
(days)
' -- IIpwaid Flow from-
Underlying
Aquifer
(gpm)
---
- Gravity Flow from
Fracture
Zoae
(gpm)
-
= Total
Miae
Inflow
(gpm)
---
1 --
210 -- -
93 -
---- 3 03 ., i
7 79 35 114 - ~
14 56 25 81 %'
30 38 17 55 r~
I 60 27 12 39 "-
90 22 10 32
1 180 16 7 23
360 11 5 16
720 8 3 11

The data in Table 2 indicates that the inflow immediately after
penetration of the fracture zone is relatively large but rapidly declines as
• the head in the aquifer is decreased due to depressurization of the nude rlyiag
aquifer. It should be anted that the calculations performed assume that the