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

4.0
.h. 4..
Y
n
I
El a"
3.0
*! 2.0
U
MATCH PARAMETERS
AP
= 1.0 psi
t
= 1.0 hr
. PD
= 0.123
tdCD =2400
CDe2* = 10
P'
= 135.4 psla
1 .o
+ DATA
- SIMULATION
0.0
0.0 0.5 1 .o 1.5 2.0 2.5
DIMENSIONLESS SUPERPOSITION FUNCTION: FLOW PERIOD 6
Figure 5-45. H-lG/Culebra Second Buildup Dimensionless Horner Plot with INTERPRET Simulation
Figure 5-46 shows a semilog plot of the rising-head
slug-test data, along with the best-fit type-curve
match. The match shown provides a transmissivity
estimate of 0.69 ftz/day (Table 5-3), slightly lower
than the estimates from the DST analyses. The static
formation pressure estimate of 134.8 psia used to
achieve the fit in Figure 5-46 is also slightly lower
than the values used in the DST analyses. This
decrease probably indicates continued dissipation of
an overpressure skin.
A comparison of the static formation pressure
indicated by the slug test with the pressures
measured by the transducer installed at the Culebra
horizon as part of the H-16 5-packer completion
(Figure 3-8) may also indicate the continued
presence of an overpressure skin during the DST's
and slug test. The transducer used for the DSTs and
slug test was set at a depth of 678.6 ft. H-16
contained water having a specific gravity of 1.02 at
the time of the Culebra testing. The slug-test
pressure of 134.8 psia reduces to 121.1 psig when
the atmospheric pressure of 13.7 psia measured by
that transducer is subtracted. The corresponding
formation pressure at the midpoint of the Culebra
712 ft deep is about 136 psig. In contrast, the
Culebra transducer of the 5-packer system, which is
located at a depth of 702.6 ft, 24 ft deeper than the
DST transducer, showed a pressure stabilization at
128 psig shortly after the 5-packer installation was
completed (Stensrud et al., 1988). With the hole now
containing brine having a specific gravity of 1.2, the
corresponding formation pressure at the midpoint of
the Culebra, 712 ft deep, is 133 psig. Hence, about
3 psi of additional pressure-skin dissipation may
have occurred after the Culebra testing was
completed. Alternatively, continued leakage of
Culebra water into the WlPP shafts may have lowered
the Culebra formation pressure at H-16.
5.2.2.8 H-17. Testing of the Culebra at H-17 was
planned to determine whether or not the well had
been successfully located in an area of high Culebra
transmissivity. The Culebra lies from 705.8 to 731.4 ft
deep at H-17 (Figure 3-9). The interval tested
extended from 703.1 ft to the then-bottom of the hole
81