Goldsmith Field: GLSAU Geology & Volumetrics - Adrian Berry, Bob Trentham, Emily Stoudt
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Goldsmith Field:
Field
GLSAU Geology & Volumetrics
Adrian Berry
Berry, Bob Trentham,
Trentham Emily Stoudt
Acknowledgements Legado Resources DOE Steve Melzer Adrian Berry Emily Stoudt Hess Hess
Presentation Outline Regional Picture GLSAU Geologic Setting Geologic Model from Core Saturation from Core and Logs Volumetrics Conclusions
Zeroing in on the target Regional Field Specific Rock Specific
Geologic Setting
• Located on the Central Basin Platform
• Analogous depositional setting to Wasson, Seminole
Fields with Active ROZ EOR Projects
Third Order Residual on top of Wolfcamp Formation
Wasson
Vacuum Hanford
Seminole
Goldsmith Wasson Seminole
Formation San Andres San Andres San Andres
Goldsmith
Discovery (Yr) 1935 1936 1936
Depth (Ft) 4,200 4,900 5,200
Pinit (psi) 1,712 1,850 2,020
Temperature (Deg) 95 107 108
API Gravity (Deg) 34 33 35
MMP (psi) 1,150 1,280 1,300
Porosity (Frac) 0.11 0.11 0.12
A basic
understanding of the
regional
i l depositional
d ii l
history and
diagenetic
g overprint
p
can identify targets.
The Ouachita
Orogeny (Penn –
early Permian) set up
the depositional
environments in the
late Permian.
Permian
B
Emma
Embar
N. & W.
Goldsmith
C B Andector E. Goldsmith
C D
C B
Goldsmith
C B
D
C
TXL D Lawson Donnelly
D
D
A 5,000 – 10,000 BOPD
Many of the best reservoirs
B 1,000 – 5,000 BOPD B
overlie major deep structures
C 500 – 1,000 BOPD Harper
D 250 – 500 BOPD
Penwell B
Jordan B
Waddell A
San Andres production in Red overlain on the Isopach of the San Andres Note northwest to southeast trend of both isopach and production. Note relationship between isopach thins and production Western boundary of production is controlled by updip deposition permeabilit barrier permeability (Sabkha)
VACUUM NORTH WARD ESTES FIELD, GOLDSMITH FIELD, SAND HILLS FIELD,
FIELD, Lea Ward County, TX Ector County, TX Crane County, TX
Co., NM
Queen
A minimum of
300 and
possibly
between 400 &
500’ of middle
and upper San
Andres is
missing at
Goldsmith
compared to Lower Queen
Vacuum
Grayburg
“Upper” J
San Andres u
d
J k
i
u
Middle SADR n
d s
k
Intermediate
i
n
s
McKnight
est ROZ base Vacuun
McKnight
Shale
Holt
Glorieta
Upper Clearfork?
Middle
Regional Cross Section Clearfork? Understanding the regional
Sand Hills – Goldsmith –
North Ward Estes –
correlations
l ti iis iimportant
t t on
Vacuum Fields
2/2011
targeting the best reservoirs
Goldsmith Structure
• Top of San Andres porosity conforms to top San Andres structure
• Structural high on GLSAU southern boundary
Top San Andres Structure Top San Andres Porosity Structure
GLSAU
GLSAU
GSAU
GSAUGoldsmith Type Log
204R
Top San Andres 4130’
(-924’)
Top Porosity 4154’
(-948’)
Gas
Cap
4181’
GOC (-975’)
Main
204R
P
Pay
4286’
OWC (-1080’)
204R
ROZ
4411’
Base ROZ (-1205’)
4436’
(-1230’)GLSAU Geologic Model
GLSAU Core Data
• Good core data coverage across the field…
o 7 Legado Cores
o 4 BEG Cores
o 9 Pan Am/AmocoGLSAU Cored Intervals
• …and good coverage vertically through the reservoir.
126R
221R
43 99
58 190 222W
304
26
204R
146
43
26
58 99
304 126R
146
190
222W
204R 221RDetailed
Core
Description
of the
GLSAU
#190 W Well,
ll
Goldsmith
Landreth
Unit, Ector
C
County,
t
Texas
15Detailed Core
Description of
the GLSAU
#204 Well,
Well
Goldsmith
Landreth Unit,
Ector County,
Texas
16Below the ROZ, the core is a partially
dolomitized fusulinid/crinoid/brachiopod
wackestone to grain dominated packstone.
Dolomite is largely confined to the rock
“matrix”, grains are calcitic, resulting in a
“limestone” log signature Porosity is
intercrystalline and moldic, averages 10-
12%, but contains only water.
17Depositional cycle boundaries are difficult
to pick in most of the fusulinid wackestone
to grain dominated packstone intervals.
However at least two significant dark
bro n m
brown, mudstone
dstone to wackestone
ackestone ccycle
cle
bases were identified below the ROZ.
Hopefully these can be carried around the
Landreth Unit.
4422.6
18 4425.7Lithologies in the ROZ are also
fusulinid/crinoidal wackestone to
packstone, but they are 90-95% dolomite,
with traces of calcite cement or remnant
crinoid grains and anhydrite. Fusulinids
have been leached, resulting in moldic
poosity. Intercrystalline and moldic pores
average 5-10%, slightly less than below
the ROZ
19GLSAU #204
San Andres Formation
4151-4160 Dolomitized Oolitic, Peloidal Grain-Dominated Packstone to
Grainstone. Core is in Gas Cap Near the top of the cored interval in the GLSAU
#204 core, fusulinids decrease significantly and
grains appear
g pp to be mostlyyppeloids ((?ooids).
) Grains
are both leached and preserved as ghosts.
Intercrystalline and moldic pores average 5-10%.
Note that the core appears less “oil stained”
because the interval is situated in the gas cap for
the field
field.
4160GLSAU #204
San Andres Formation The first evidence of stromatolitic algal
4141-4150 Dolomitized Tidal Flat Capped Cycle w/ Stromatolitic Algal
Laminations. Core is in Gas Cap laminated tidal flat deposits occurs at the
top of the GLSAU #204 core. Porosity is
significantly reduced (1-3%). Cycle tops are
picked relatively easily in intervals that
display tidal flat deposits.
4143
4143Conclusions To Date
Both the GLSAU #190 and the GLSAU #204 cores contain
San Andres lithologies that are skeletal
(fusulinid/crinoid/brachiopod
fusulinid/crinoid/brachiopod)) wackestones to grain
dominated packstones
The basal 30 feet of the # 190 core also contains rugose
corals and bryozoa
bryozoa,, indicating that the most open marine
deposits occur at the bottom of the core
The top 10-
10-20 feet of the #204 core is composed of
peloidal (?oolitic
(?oolitic)) grain
grain--dominated packstones and also
displays the first stromatolitic algal laminated deposits.
Open shelf, shallowing upward, tidal flat cap.Core Fluorescence – GLSAU 204R
• Consistent fluorescence throughout CO2 flood interval.
Gas Cap Main Pay Oil Residual Oil Zone Below
(Resaturated)
TOP
Zone
TOP
(MPZ) TOP
(ROZ) ROZ
TOP
O
BASE
BASE BASE BASE24
Gas-Oil Conttact Oil-Waater Contact Base of Commercial
C
at Discoverry at Discovery
D R
ROZ
(-975) (-1080) (-1
1230)
Gas Main
R
ROZ
Cap Pay
• Similar oil saturation in lower Gas Cap, Main Pay, and ROZ
GLSAU CORE OIL SATURATION
Avg Top Porosity (-940)
Commercial CO2 Flood In
ntervalROZ Field Saturation Progression
100% So 0%
GAS
CAP
MAIN PA
OPERATOR
CONTROLLED
OOIIP for Tertiary RF
WATERFLOOD
AY
D
e
ROIP
p
t
h
ROZ
NATURAL
HYDRODYNAMIC
FLUSH
WATER
W
31Corrected Conventional Core Saturations
• Adjusted core oil to reservoir conditions and applied an average loss factor of 7%
• Legado adjustments are consistent with recent sponge core results from Seminole
Goldsmith ROZ Core – Surface,
Surface Reservoir
Reservoir, & Corrected Data Goldsmith vs Seminole - So Correction to Reservoir
Extraction Loss
36%
Shrinkage 29%
Measured Oil
22%
at Surface
(1) Correct for Oil Shrinkage (2) Correct for Fluid Loss During Extraction
• Apply current Oil FVF, Bo = 1.30 rb/stb, to • Assume reservoir liquid filled & fluids lost during extraction were at
convert measured oil saturation from surface to same oil/
oil/water
ater ratio as flfluids
ids meas
measured
red
reservoir conditions • Use lesser of 10% or the calculated oil saturation loss for each sample,
• Average correction ~ 6.6% So • Average correction ~ 7.3% So
• Consistent with Seminole correction ~ 6.3% So • Consistent with Seminole correction ~ 8.0% SoBase ROZ (Base of Commercial Sor)
• Base ROZ identified using core saturations, fluorescence, and log response
• Commercial CO2 flood interval is based upon a flat base of ROZ (-1230’)
• Base ROZ ((-1230 ss))
58 • Gradual oil saturation
decrease
• Lithology remains
Main
Pay
OWC
4266’
(-1080’)
constant
58 • Transition zone
present
ROZ
4416’
Base ROZ (-1230’)
sition
Zone
Trans
58
4586’
BOSO (-1300’)Base ROZ (Lithologic Change)
• Lithology change can be mapped using log and core data
• Small portion of ROZ is truncated by non-reservoir rock
• Abrupt decrease in oil
204R saturation
• Resistivity decreases
• Grain density
decreases
Main Pay
• PE curve increases
4286’
OWC (-1080’)
204R
ROZ
4411’
Base ROZ (-1205’)
4436’
(-1230’)
204RTilted ROZ Contact (sub -1230’ SS)
• Calculated SW curves have a strong correlation with core data
• Used SW to map a tilted Base of ROZ contact
• Seminole also exhibits a tilted Base of ROZ contact (Honarpour, SPE 133089)
58 114R 190 222
Subsea
epth(ft) GR RESD NPHI_DOLO_ADJ CORE_FLUOR_S
ARCHIEGEN_SW
CORE_SO_S GR RESD NPHI_DOLO_ADJ ARCHIEGEN_SW GR RESD NPHI_DOLO_ADJ CORE_FLUOR_S
ARCHIEGEN_SWCORE_SO GR RESD NPHI_DOLO_ADJ CORE_FLUOR_S
Subse
Depth(
ARCHIEGEN_SWCORE_SO
Tilted ROZ PhiH
0 75 0.2 2000 0.3 -0.1 -10 110 1 00 100 0 75 0.2 2000 0.3 -0.1 1 0 0 75 0.2 2000 0.3 -0.1 -10 110 1 00 100 0 75 0.2 2000 0.3 -0.1 -10 110 1 00 100
-1000 -1000
MAIN
PAY
4250
-1050 (-1051) -1050
4250
4250
(-1061)
(-1064)
4250
(-1073)
4300
-1100 (-1101) -1100
4300
4300
(-1111)
(-1114)
4300
(-1123)
-1150 ROZ 4350
(-1151)
4350
-1150
4350
(-1161)
(-1164)
4350
(-1173)
4400
-1200 (-1201) -1200
4400
4400
(-1211)
(-1214)
4400
((-1223)
1223)
Tilted ROZ 4450 Limey San Andres
-1250 (-1251) -1250
4450
4450
(-1261)
(-1264)
4450
(-1273)
Transition Zone
4500
-1300 (-1301) -1300
4500
4500
(-1311)
(-1314)
4500
Free Water Zone (-1323)
-1350 ELEV_KB : 3,186 ELEV_KB : 3,177 ELEV_KB : 3,199 ELEV_KB : 3,189
-1350
TD : 4,220 TD : 4,512 TD : 4,535 TD : 4,429Porosity Calculation and Data Control
• Consistent methodology used to calculate porosity across the field
• Good log data coverage across the field
Calibrated log porosity using
measured core porosity
Sonic
S i porosity:
it
• Matrix 41.1 µs/ft
• Fluid 185 µs/ft
Neutron Porosity:
• Generated a porosity transform
based on Neutron True Porosity
correction chart to fit GLSAU core
porosity
• Only open hole neutron logs
were used
Log Coverage Used For
Volumetric CalculationsGeology Summary Comments
• ANALOG:
• GLSAU is analogous to Wasson and Seminole fields
• ROZ:
• In known hydrodynamic fairway and environment for ROZ development
• DATA:
• Extensive core and log data with good spatial coverage exist in the field
• High confidence in porosity and existing fluid saturations
• VOLUMETRICS:
• Total Commercial CO2 Flood in Phase Area OOIP
• Mapped OOIP ties well with material balance OOIP
• Upside of Tilted ROZYou can also read
