Beauheim 1987 - Waste Isolation Pilot Plant - U.S. Department of ...

102
I I 1 1
1
W
K
3
v)
v)
W
K
n
v)
W
J
2
v)
2
W
10'
v) 100
0
z
a io-'
MATCH PARAMETERS
AP
= 1.0 psi
t
= 1.0 hr
PD = 0.1
tdCo =31
tC,,ezs), = 0.4
(CDezs)t-m = 4.0 x 10-3
e-2s = 0.9
Pi
= 44.87 psig
NO-FLOW
BOUNDARY
AT Do = SO00
-
0 PRESSURE DATA
* PRESSURE-DERIVATlVE DATA
SIMULATIONS
10-2
I 1 I I
10-2 io-' 109 10' 102 103 104
DIMENSIONLESS TIME GROUP, t,/Co
Figure 5-21. H-8b/Culebra Pumping Test Drawdown Log-Log Plot with INTERPRET Simulation
well with a smaller radius. Conversely, a well with a
negative skin factor should behave like a well with a
larger radius. H-8b, with a skin factor of -7.2 and an
actual radius of 0.255 ft, behaves like a well with a
radius of about 340 ft.
The reason for the two-fold discrepancy between the
transmissivity reported by Mercer (1983) and that
obtained from this test is not clear. The hydraulic
boundary indicated by this test analysis was either
not felt by the earlier, shorter test, or was not
recognized. Without either data from multiple
observation wells or independent
geologicfgeophysical information, the orientation of
the boundary cannot be determined.
Figure 5-22 shows a log-log plot of the H-8b recovery
data along with an INTERPRET simulation using
exactly the same model as was used in the
drawdown simulation (Figure 5-21). In an ideal
system, this model should fit both the drawdown and
recovery data identically. In general, the fit is
excellent until extreme late time, at which point
apparent "over-recovery" on the order of 1 psi is
observed (most clearly in the rise of the pressure
derivative). This over-recovery may be related to
residua1 recovery from some pre-test pumping
activities associated with checking the pump and
filling the discharge lines (INTERA Technologies,
1986). Figure 5-23, a linear-linear plot of both the
drawdown (compensated for the initial 3.2psi pump
loss) and recovery data along with an INTERPRETgenerated
simulation, also shows the generally
excellent tit between the data and the simulation, as
well as the over-recovery beginning about 70 hr into
the recovery period.
In general, the H-8b response was very similar to the
responses observed at wells H-3b2. H-3b3, and
WIPP-13 when those wells were pumped (Beauheim,
1987a and 1987b). At these locations, the Culebra
exhibits unrestricted interporosity flow with rapid
transition between flow from the fractures only and
flow from both the fractures and the matrix This type
of response contrasts with the responses observed
during pumping tests at wells DOE-1 (see Section
64