I
Colin Goranson
C()C()C()C()C()Geo
Geological Engineering Consultant
th erm al C()C()C()C()C()C()C()Oil an d GasC()C()C()C()C()C()C()C()C()Min eralsC()C()C()C()C()C()C()C()CX)H
1498 Aqua Vista Road, Richmond, California 94805 (510) 234-0522 FAX (510) 234-5881
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Email [email protected]
Thursday, December 13,2001
SB GEO, Inc.
1010 Power Plant Drive
P.O. Box 18087
Reno, NV 89511
(775) 852-1444 FAX 852-1807
Attn: Bill Price/Eric Call
RE: Discharge Testing ofMTH 24-33
Dear Bill,
SB Geo, Inc. drilled the Meyberg temperature slim hole 24-33 (MTH 24-33) on
its Meyberg Property at Steamboat Springs, Nevada. The slim hole was cored to total
depth. Funding was through a cost share program with DOE under the "Geopowering the
West" program.
The slim hole was completed on 10-Mar-200 1 through fractured granodiorite to a
total depth of 2000 feet. The slim hole location is shown in Figure 1. The well completion
and a geologic description are shown in Figure 2.
MTH 24 -33 was discharge tested on November 30, 2001. The well was
discharged into a small diameter atmospheric flash tank. Water rate from the well was
measured with a V-notch weir. Total discharge rate during the test was ;::::35 gpm.
Produced fluids were piped through a temporary 4" diameter injection line to slim hole
12-33 for injection back into the geothermal system. A produced fluid sample was taken
during discharge testing for chemical analysis.
Page lof3
Static temperature versus depth data, shown in Figure 3, was obtained prior to
discharging the well. Also shown in Figure 3 are static pressure and temperature survey
data obtained on 1-May-O 1. The static water level is 315 feet. Maximum measured
temperature, in the open hole section of the well, is ::::::324°F.
The temperature and spinner tool (the spinner tool did not operate correctly and
no pressure tool was available) were then set at 730 feet (inside 3 112" casing) to monitor
downhole flowing temperatures after initiating flow. The data obtained (after initiating
flow) at 730 feet are shown in Figure 4. The temperature spikes as a function of time are
due to fluids located at depth moving up the well bore. The temperature spikes
correspond to measured temperatures encountered at depth during static surveys (see
Figure 4). Stabilized flowing temperature was ::::::307°F at 730 feet. The available data
indicate that all of the well flow was coming from below 1,700 feet.
Temperature and spinner survey data were then obtained during discharge. The
data are shown in Figure 5. The increase in temperature as fluids move up the hole from
>1,700 feet (current maximum depth of the well is ::::::1,750 feet) is probably due to
conductive heating, however, no spinner data are available to make this determination.
The flowing temperature data indicate that the flash point was at approximately
425 feet. This data, along with the static pressure data obtained on I-May-O I, indicates
that the well has high permeability, similar to other wells drilled in the area.
The fluids coming from below 1,700 feet mask the possible production zones
located between depths of 1,100 feet to 1,400 feet. This behavior also occurred in slim
hole GTH 87-29 drilled on the Giusti Lease (see Figure 1 for well location). This well,
GTH 87-29, also allowed deeper cooler fluids to flow up the well bore.
The test data for MTH 24-33, combined with other data for the area, indicates that
there is a large producible resource with temperatures of ::::::305°F. However, the resource
of current interest is in the 315°F to 325°F range that lies between 1,1 00 feet to
1,400 feet. In order to investigate this zone, MTH 24-33 needs to be plugged-back to
Page 2 of3
;;::; 1,400 feet. This can (probably) be accomplished by placing sand in the lower portion of
the well up to a depth of;;::;1,400 feet and discharge testing the well. If the sand does not
remain in the well, a 5-foot cement plug may be required on top of the sand. The total
volume of sand required should probably be based on the original 2,000-foot depth of the
well. Although the well seems to be bridged-off to survey tools at the 1,771-foot depth,
the core drilling equipment never encountered any bridge at this depth.
Cordially,
Colin Goranson
[email protected]
Page 3 of3
•
Production Well
•
Injection Well
Exploration Well
SPPCO
MTH 12-33
/
_-~------"
--------c ; /'
::::.~.
I
r---...._________
-.
I
)
Temporary
' \ / '/
\
',...,.-
-'~
.-'
:" , (
..,......
411 Injection
Pipeline
~
~
-
- 'Rd .
Figure 1) Location of Meyberg Stratigraphic Slim Hola MTH 24-33
Stratigraphic Hole MTH 24-33
I-Static Temperature 1-May-01 I
Temperature (OF)
75
50
100
125
150
175
200
225
250
275
300
325
O~~~~~~~~~~~~~~~~~~~~~~~~~~
o - 20' basalt
4 1/2" Flush Joint
casing set at 250'
250
108' to 240' Granodiorite, highly altered,
soft. Tight fractures.
Open
fracture
500
597'-603'
dip 70° - 90°
3 112" Flush Joint
casing set at 771 '
750
-
Open
fracture
I l)
1039' -1 040'
~
-
dip 70° - 90°
..c 1,000
a.
Il)
c
Open
fracture
1,290'-1,291 '
dip 70° - 90°
1,250
240' to 1,890'--------Granodiorite, firm, hard, lightly altered. Biotite fresh
to partly altered to clays. Numerous fractures,
many with slickensides and thin «1/4") zones of
mylonitized rochs indicating displacive movement.
Fracture dips from 40° to 90° with many 60° dips.
Numerous fillings of chlorite, quartz and calcite .
Permeable fractures w/openings 1/8" to 1" wide
occur at 597'-603'.1039'-1040',1290'-1291' and
1809'-1810'.
Numerous zones of 2' to 8' core length with pervasive
chlorite and clay alteration yielding softer rock. These
may be associated wi fractures
2.9"
, Open
hole
1,500
Limestone-dolomite inclusions in the granodiorite
occur at 1367'-1375' and 1433'-1436'.
Granodiorite to TO.
,
Open
fracture
,
1,809'-1.810'
dip 70° - 90°
,
,
1,750
, ,
, ,
,
,
PBTO 1,771'
,
2,000
TD 2,000'
Completed 10-Mar-01
Figure 2) Well Completion, Geologic Description and Static Temperature Data for
Slim Hole MTH 24-33
---Temperature 30-Nov-01
--<r--
Temperature 1-May-01 - - - Pressure 1-May-01
Temperature (OF)
200
225
250
275
300
325
Onn-n~~-+~~~~+-~~~-+~~~~+-~~~~
4 1/2" FI~sh Joint
casing stat 250'
250
+-
Water Level
=315 feet
500
3 1/2" Flush Joint
750
-
casing set at 771 '
Q)
Q)
-
" '-"
J:
1,000
0-
J
Q,)
C
J
J
J
J
, ,
,
I
1,250
; ;
! I
! I
I
I
, ,
2.9" open hole
, ,
,
J
I
J
i i
,
1,500
i
;
; !
1,750
PBTD 1,771 feet
o
50
100 150 200 250 300 350 400 450 500 550 600 650 700
Pressure (psia)
Figure 3) Static Pressure and Temperature Data versus Depth for Slim Hole MTH 24-33
I
325~--------------------------------------------------------~
MTH 24-33
30-Nov-2001
",320°F Fluids
from ",1,300'
Temperature versus Time with
Tool Located at 730 feet (inside casing)
1
",315°F Fluids
from ",1,000'
320
-u0 .
Q.)
~
::::J
ctI
~
315
Q)
0-
E
Q)
I-
310
~300°F
Fluids
from> 1,700'
305+-~~~~+-~~~~+-~~~~r-~~~~r-~~~~r-~~~~
a
5
10
15
20
25
Elapsed Time @730 feet (minutes)
Figure 4) Temperature versus Time at 730 feet During Discharge Testing of
Slim Hole MTH 24-33
30
....
'
I-Static Temperature
c
Flowing Temperature I
Temperature CF)
295
300
310
305
315
320
325
0~~~,-,-1-~~~~~-.-.-,-,~-,~~~-+-,~~~-4~~~~~
MTH 24-33
30-Nov-2001
Flowing ",,35 gpm
250
4 1/2" Flush Joint
casing set at 250'
Flash Point =426 feet
j
500
750
3 1/2" Flush Joint
casing set at 771'
-
..-..
--a.
Q)
Q.)
..r:. 1,000
Q.)
c
1,250
1,500
1,750
29'
~I
opoo
@
fj
hOI~/
r
i
PBTD 1,771 feet
TD 2 ,000'
2,000L-~------------------------------------------------~
Figure 5) Flowing and Static Temperature versus Depth for Slim Hole MTH 24-33