RDS Subtask Number:
41817.606.[040040000800]
RDS Subtask Title:
[An integrated geosciences approach to CO2 leakage
prediction and detection at geologic sequestration
sites]
Report Dates:
Start Date: 10/01/05
End Date: 01/14/10
Principal Investigator/Contact Info: P.I.: / 304 293 6431 / tom.wilson@mail.wvu.edu
Associates:
Henry Rauch and Tim Warner
DOE Subtask Manager:
[Art Wells, Don Martello, and Dave Wildman]
RDS Task/Subtask Manager:
Fred Gromicko/Paul Deffenbaugh
FINAL REPORT
An integrated geosciences approach to CO2 leakage prediction
and detection at geologic sequestration sites
Thomas H. Wilson, Henry Rauch and Tim Warner, West Virginia University Department of
Geology and Geography
1.0 Executive summary
Geophysical and geological characterization was undertaken of select NETL Carbon
Sequestration pilot sites in support of NETL’s tracer and soil gas monitoring efforts. The
majority of the research was focused on the Southwest Regional Partnership for Carbon
Sequestration’s San Juan Basin Pilot site in the High Rate Fairway for coalbed methane
production from the Fruitland coals. Additional investigations were also undertaken on
the Michigan Basin Pilot, Bozeman Montana ZERT test site and the Russell County, VA,
SECARB site.
Efforts at these sites incorporated independent subsurface mapping; acquisition,
processing and interpretation of satellite imagery data (QuickBird, INSAR, and radar),
hyperspectral imaging assessment; field mapping of surface fracture systems; acquisition,
processing and modeling of EM conductivity data; surface core sampling; acquisition and
interpretation of a comprehensive well log suite from the injection well, FMI log analysis
of subsurface fracture data, design and specialized processing of the time lapse VSP
monitoring survey and 3D seismic interpretation. In the following report we summarize
selected research results from 3D seismic, near-surface terrain conductivity mapping,
injection well logging and VSP analysis. The project is funded by the U.S. Department of
Energy (DE-AM26-04NT41817 (606.04.04) with technical and financial management
through the National Energy Technology Laboratory and RDS respectively. Analysis
undertaken in this 4 year study is extensively reported in 53montly reports.
Structural mapping based on geophysical logs from more than 170 wells near the
proposed injection site and surrounding area did not reveal the presence of significant
local structure within a mile or so of the injection well. Near the site, the Fruitland top
and base dip northeast about 30 feet per mile. Low relief structures are present in the
surrounding area. The most prominent structures include structural highs to the south and
southeast of the site on the top and base of the Fruitland Formation. Well log
interpretation alone suggests little possibility that these gently dipping structures in the
immediate vicinity of the pilot site could enhance fracturing in the Fruitland coals and
overlying strata (see Henthorn and Wilson, 2007).
Research at the site also included an evaluation of satellite radar interferometry
(conducted in August-October, 2006) to evaluate the possibility of detecting ground
displacements related to CO2 injection and coalbed methane production. The test revealed
good coherence between images collected over a 72 day interval. Surface deflation
resulting from oil and gas production in the area during that period was not observed.
Analysis revealed the method should be capable of detecting sub-centimeter scale surface
deformation with 8 meter ground cell resolution. The SWP continued acquisition of radar
images for potential use in the evaluation of tiltmeter measurements made by Pinnacle
over the site (see Wilson et al. 2008).
Seismic interpretation of about 9 square miles of 3D seismic data centered around the
injection well revealed that the late Cretaceous Fruitland Formation forms a well defined
seismic sequence with high amplitude reflections marking the top and base of the
sequence. Internal reflection patterns suggest considerable stratigraphic complexity in the
Fruitland Formation depositional systems. The lower Fruitland coal reflection events are
fairly continuous across the site whereas the middle and upper Fruitland coal events are
fairly discontinuous and difficult to correlate through the surrounding area.
Isochore (travel time difference) maps of the Fruitland sequence and lower Fruitland coal
intervals reveal considerable variability of thickness throughout the area. Thinning of the
Fruitland sequence occurs along a NW-SE trend through the pilot site that coincides with
a high in the base of the sequence. Stratigraphic buildup and pinchout are observed in the
underlying Pictured Cliffs seismic sequence. We speculate that thinning of the Fruitland
sequence observed along the NW-SE trend is associated with differential compaction
over northwest trending shoreline sand bodies in the upper Pictured Cliffs Sandstone and
that differential compaction of the Fruitland may enhance local fracture intensity along
this NW-SE trend (see Wilson et al. 2009).
One of the principle findings is that extensive fracture systems exist within the sealing
strata. These fracture systems could increase the probability of long-term CO2 leakage.
3D seismic interpretation suggests these small faults and fracture zones have limited
vertical extent. Major penetrative faults are not evident in the 3D seismic; however, the
presence of numerous open fractures in the sealing strata have variable trend and suggests
that vertical migration of injected CO2 is possible. Open fractures are encountered from
depths of 1000 feet subsurface within the San Jose Formation to 2900 feet within the
upper Fruitland Formation. The distribution of open fractures has modes with NW, N and
NE trend. Given that these open fractures are encountered locally within the injection
well it seems likely that arbitrarily located wellbores would penetrate open fractures with
similar frequency. A similar frequency of open fracture systems throughout the site could
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Wilson et al. RDS Final report – March 2010
facilitate interconnection and long-term upward migration of CO2 through more
penetrative fracture zones interpreted in the 3D seismic. The fracture analysis presented
in this paper provides the basis for development of a discrete fracture network that could
be used in flow simulations. Models that incorporate discrete fracture networks with
properties identified in this study could be used to assess the range of possible leakage
rates that might occur through overburden strata. The results of our studies helped locate
additional tracer monitoring efforts on both the San Juan Basin and Michigan Basin pilot
sites.
Work continues on the San Juan Basin (with a focus on analysis of time-lapse VSP and
reservoir compartmentalization within the Fruitland coal sequence), Michigan Basin
(analysis of time-lapse 3D seismic with a focus on detection and interpretation of time
lapse AVA responses); and technical support to help integrate tracer and soil gas findings
obtained at the Russell Co. VA site into subsurface geology.
At the MSU-ZERT Bozeman Montana field site, hydrogeologic data were collected the
past four summers, during the CO2 injection tests conducted by Montana State University,
to test the feasibility of developing efficient hydrologic monitoring techniques using
monitoring wells for detection of surface seepage of injected CO2 gas. Two such
techniques were tested and proven successful, involving the shallow MSU glacial
outwash aquifer and CO2 injection into a ~2.8 m deep horizontal test well. One
successful technique involved the sampling and chemical analysis of water to determine
the theoretical concentration of dissolved CO2 gas; when such gas increased by >50 %
relative to background (as from 0.02 % to >0.03 %) aqueous chemistry for shallow
ground water indicated the detection of CO2 gas seepage at least 3 m laterally from the
CO2 injection well. The second technique, involving the analysis of vadose zone gas ~0.8
m above the water table (head space gas from monitoring wells), was even more
successful (sensitive); when this gas increased from 1.5 – 2.5 % (background volume
concentration range at ~0.5 m depth) to at least 3.5 %, a positive detection signal for CO2
gas seepage occurred, out to at least 3 m laterally from CO2 injection well.
Another important accomplishment at the MSU-ZERT field site was the development of
a new field technique for accurately measuring vadose zone gas CO2 concentration in
monitoring wells, when that gas exceeded 20 % by volume, due to major leakage of
injected CO2 gas; before this research project the highest percentage of CO2 gas that could
be accurately measured in the field was 20 %, using a portable CO2 probe and meter
made by Vaisala Inc., the world’s premier CO2 monitoring equipment company. With
major help on site from the U.S. Geological Survey MSU-ZERT team, a gas dilution
chamber was designed, built, and used to accurately measure high CO2 values. This
technique will in the future allow quick feedback in real field time, necessary for the
adjustment of seepage monitoring techniques used at CO2 injection sites, and for the
quick assessment of any public danger that would necessitate shutting down CO2
injection. Before this research, delays of days to weeks for shipping and lab analysis
were necessary to obtain accurate high CO2 concentration values for field gases sampled
in glass vials.
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1.1 Approach
The experimental, analytical and fabrications methods used in this research are fairly
standard, except for the CO2 gas dilution chamber method. This and other relevant
references are provided in the Results and Discussion section.
1.2 Results and Discussion
i. 3D Seismic
Seismic analysis incorporated synthetic seismic ties, horizon interpretation and mapping
of a 9 square mile area surrounding the site. Post-stack processing incorporated a variety
of edge and discontinuity enhancement algorithms to extract and enhance seismic
features that might represent potential fracture zones and faults; structural features that
could facilitate migration of injected CO2 into overlying strata.
Post stack processing incorporated edge enhancement and event similarity prediction
algorithms, along with calculation and evaluation of tuning cubes and Ant Tracking. The
analysis reveals internal compartmentalization of the Fruitland coals through this area
accompanied by fairly extensive system of interpreted fracture networks concentrated in
the primary seal (the Kirtland Shale).
Seismic analysis reveals complex subsurface geology at the scale of the pilot site.
Amplitude anomalies are numerous in the vicinity of the injection well in addition to
kilometer wavelength structures. Regional studies by Fassett (1997), Wray (2000), reveal
the presence of considerable heterogeneity within the Fruitland Formation and individual
seams. The detailed study of Ayers and Zellers (1994) conducted near the pilot site
reveals considerable complexity in the Fruitland Fm depositional systems. In a schematic
sense, Wray (2000) represents the variety of heterogeneity that can be encountered in the
Fruitland coals (Figure 1). Fassett (1997) indicates that continuity of subsurface coals
over distances of a mile is speculative, at best. Pinchouts, local fault truncations, channel
scour and facies changes are all encountered in the Fruitland coals. Seismic analysis
provides a glimpse of some of this heterogeneity.
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Wilson et al. RDS Final report – March 2010
Figure 1: Schematic of coalbed methane reservoir cross section (taken from Wray, 2000).
The black and white variable area wiggly trace display (Figure 2) illustrates basic
features associated with the seismic response of the Fruitland sequence.
Figure 2: In this 2D seismic display, locally steepened dips are evident across the area. This line
trends northeast-southwest Considerable internal discontinuity of reflection events is evident
throughout.
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Wilson et al. RDS Final report – March 2010
3D seismic interpretation reveals that the Late Cretaceous Fruitland Formation forms a
well defined seismic sequence with high amplitude reflection events marking the top and
base of the sequence. The pattern of internal reflection events is generally parallel and
conformable near the top and base of the sequence. However, considerable internal
reflection discontinuity is present. This discontinuity appears to be associated primarily
with the upper and middle Fruitland coals. The 3D seismic view of the Fruitland
Formation is considerably different than that inferred from well log cross sections. The
seismic reveals significant discontinuity as noted, whereas the coal intervals shown in
well log cross sections often suggest continuity which may, in fact, not be the case. These
are problems related to sparse sampling that we are all familiar with. Seismic
interpretation also reveals the presence of local fold-like structures (Figures 2 and 3) with
wavelengths ranging from 1 km to 3.5km accompanied by relief of 6 feet to 60 feet.
Figure 3: This northwest-southeast line illustrates a similar level of reflection discontinuity along
the axis of the basin. Local structural features are also evident in the display.
The origin(s) of these structures is uncertain. In some cases, time-structural rise across
the top of the Fruitland is accompanied by a drop across the base. This could, for example,
represent time-sag associated with increased travel time through relatively low velocity
intervals within the Fruitland sequence. Other time structures observed in the Fruitland
carry upwards through overlying Paleocene and Late Cretaceous intervals. For example,
to the northwest (Figure 4) there is a gentle structural rise in both the upper Fruitland and
the Kirtland and adjacent reflection events. On the southeast end of this line small folds
in the upper and Middle Fruitland appear to have some hint of continuation into intervals
overlying the Kirtland.
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Wilson et al. RDS Final report – March 2010
Geologic controls to consider include detachment within the coals and differential
compaction associated with lateral variations of net compressibility associated with
variations in depositional environments and lithologic heterogeneity within the Fruitland
sequence. Although regional face cleat trend in the area has NE-SW trend, Ayers and
Zellers (1994) note that compaction folding of coals above and below channel sandstones
could produce localized areas of enhanced fracture density. Their cross sections reveal
coal splitting associated with fluvial channel systems within the Fruitland Fm.
Compaction induced coal fracture systems are discussed by Donaldson (1979) and Tyler
et al. (1991). Internal reflection patterns observed in the 3D seismic from the area
(figures 2 and 3) suggest the presence of some channeling.
Figure 4: Shallower reflection events associated with the upper Kirtland Shale, the Ojo Alamo
Sandstone and Nacimiento Fm.
Seismic displays (Figures 3 and 4) suggest thinning to the southeast. The isochore map
(Figure 5) shows areas of thinning (orange and red areas) that stretch to the southeast
along the axis of the basin. The morphology of these patterns is not clearly associated
with specific depositional environments. Sandstone deposits in the Fruitland formation
generally flowed northeastward onto coastal areas of the Western Interior Seaway. While
there appear to be channel like features in some vertical displays, we do not see the dipelongate (northeast oriented) pattern of sandstone bodies expected in the Fruitland (Ayers
and Zellers, 1994). The isochore might reveal depositional patterns if they are
accompanied by differential compaction. The change in travel time through the Fruitland
sequence encountered in the vicinity of the injection and production wells is at most 8
milliseconds. Using an average interval velocity of 10,600 feet per second for the
Fruitland, this corresponds approximately to thickness changes on the order of 42 feet.
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Wilson et al. RDS Final report – March 2010
Reflection events arising from the lower Fruitland coal are continuous and well defined
throughout the area. Travel time changes from these continuous internal reflections in the
vicinity of the injection well and surrounding production wells correspond to thickness
variations on the order of 2 to 3 feet, or so (Figure 6). This estimate assumes a constant
velocity of about 7,700 feet/second in this coal interval. A relatively good synthetic tie
was obtained between the synthetic and seismic response near the well (Figure 7). The
synthetic seismic response is also compared to the seismic response along a NE-SW line
that passes through the EPNG COM ING 1 well (Figure 8). The following negative cycle
was used due to its continuity. While the events interpreted to be associated with the
lower Fruitland coal do not coincide with the actual top and base of the lower Fruitland
seam, they do provide a measure of the internal thickness variations and structure of this
lower coal zone.
Figure 5: Isochore map of the interpreted Fruitland Formation seismic sequence.
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Wilson et al. RDS Final report – March 2010
Figure 6: Isochore map of the interpreted lower Fruitland coal zone.
Figure 7: Synthetic seismogram is compared to seismic traces in the vicinity of the injection well.
The highlighted red trace in the center group of traces is the trace closest to the well. Traces to the
left represent positive polarity and those to the right, negative.
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Wilson et al. RDS Final report – March 2010
Figure 8: A detailed view of reflection events associated with the lower Fruitland coal. See
Figure 7 for reference. Southwest is to the left and northeast to the right. The injection well is
located in the center of the line. Synthetic traces are overlain in blue.
ii. Attribute analysis
Several seismic attributes were calculated and examined to determine if additional
insights can be gained from the seismic data regarding the structural and stratigraphic
integrity of the reservoir and overlying strata. Our main objective was to assess the
potential for vertical leakage of injected CO2. Thus we are interested in identifying
possible fracture zones and faults that might facilitate the escape of injected CO2 into
overlying formations and possibly to the surface.
An example of this analysis (Figure 9) illustrates how additional information can be
extracted regarding the presence of possible fracture zones and fault systems. The
absolute value of the derivative of seismic amplitude was calculated. An AGC was
applied to the derivative to normalize amplitude variations. Between the Fruitland top
and base (close-up view Figure 10) there are some subtle features that may be associated
with vertically juxtaposed stratigraphic pinchouts or internal faults. Some of these occur
near the periphery of the pilot area as defined by the production wells. Considerable
evidence of fracturing and minor faulting is observed in the Kirtland Shale (Figure 9).
While large penetrative faults are not present in the strata overlying the Fruitland Fm.,
considerable fracturing of overlying intervals is suggested by the data. If the integrity of
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Wilson et al. RDS Final report – March 2010
the reservoir is compromised, eventual escape to the surface might be facilitated by these
fracture systems.
The closeup view (Figure 10) along this same dip line reveals some subtle disruptions of
amplitude within the Kirtland Shale to the southwest near one of the producing wells
(COM A 300). The injection well sits on top of a subtle structure in the lower Fruitland.
Stratigraphic pinchouts coincident with this high are observed in the underlying Pictured
Cliffs Sandstone (also see reflections below the Fruitland in Figure 8). The Fruitland
isochore (Figure 5) reveals a northwest trending zone of thinning in the Fruitland
sequence. Thinning correlates to the presence of reflection terminations against the lower
Fruitland sequence boundary. These reflection patterns are interpreted to be associated
with northwest trending shoreline sands in the Pictured Cliffs Sandstone. We speculate
that sequence thinning is related to differential compaction over a shoreline sand body.
We also speculate that differential compaction could enhance fracture intensity along this
northwest trend, particularly in the lower part of the sequence where interpreted
differential compaction is more pronounced.
Figure 9: Gain adjusted absolute value of the finite seismic amplitude difference reveals
vertically continuous amplitude disruptions that cut through laterally coherent reflection events.
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Wilson et al. RDS Final report – March 2010
Figure 10: Close up view of finite difference attribute along the dip line shown in Figure 8. This
line passes through the COM A 300 well about 1200 feet southwest of the injection well. Local
structure in the Fruitland coal, stratigraphic pinchouts and amplitude disruptions are present in the
vicinity of the injection well.
Subtle seismic indications of fracturing within the Fruitland sequence are present in
places (e.g. Figure 9), however, the finite difference computations do not provide clear
evidence of local faults within the Fruitland Fm. The results obtained from analysis of
additional seismic attributes will be presented at the meeting. One of these attributes (Ant
Tracking) reveals a regular system of discontinuities interpreted to be fracture zones or
small faults within the Fruitland Fm. Rose diagrams of Ant Tracks reveal pronounced
clusters with N50-55E trend throughout the Fruitland (e.g. Figure 11A). Less pronounced
NW trending clusters are infrequently observed. The NE trend is also very pronounced in
the overlying Kirtland Shale (e.g. Figure 11B), Ojo Alamo Sandstone and Nacimiento
Formation.
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A.
B.
Figure 11: Rose diagrams of Ant Tracks mapped at A) 570 ms within the Fruitland sequence
and B) 480ms within the middle Kirtland Shale sequence.
iii. Surface EM Characterization
Approximately 70 line kilometers of EM data were collected over the site to locate flow
paths in the near-surface sandstone that caps the site mesa. In some cases, surveys were
repeated using only two transmission frequencies to gain to improve transmission power
and signal-to-noise ratio. The high frequency response (47,000 Hz) over the site reveals
complex conductivity variations across the site associated with soil distribution, site
infrastructure and varying water saturation in the near surface (upper 10 meters) at the
site.
Conductivity inversions reveal continuous resistivity layering down to depths of about 8
meters beneath the surface. The low conductivity area that opens like a fan to the west
(see map view Figure 12) appears to consist of a headward conduit that extends from the
surface down into higher resistivity less conductive areas of the sandstone that caps the
mesa. The reveals a layered subsurface consisting of three layers that become
increasingly resistive with depth (Figure 13).
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Wilson et al. RDS Final report – March 2010
Figure 12: Locations of conductivity profiles are also shown (red lines).
Figure 13: Layered inverse models developed along the north-south cross section.
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Wilson et al. RDS Final report – March 2010
Low conductivity channels (high resistivity or blue areas in figures 12 & 13) are
interpreted to represent high permeability well drained areas in the sandstone that caps
the site mesa. The low resistivity (red) areas are probably controlled by variable soil
thickness across the surface of the mesa.
The area in the vicinity of the injection well consists of a patchy distribution of low
conductivity areas that are the most likely conduits for near-surface migration of CO2 into
the atmosphere.
iv. Logging
Logging operations were conducted by Schlumberger logging services. The upper part of
the well was logged on May 10th. Logging depths for the different tools varied but
extended roughly from 224 ft to 2933 ft subsurface. Logs in the upper part of the hole
included the Platform Express, FMI log and the Sonic Scanner for anisotropy and
mechanical properties. The VSP surveys were run on June 3rd and 4th. Following that the
borehole was extended through the Fruitland section and on June 16th and 17th two
additional runs were made to provide observations from the Fruitland Formation. The
second logging run extended roughly from 2846 feet to 3158 feet and included gamma
ray, density, PEF and Sonic Scanner runs.
Sonic Scanner and FMI Log Observations: The injection well was drilled and logged
in two stages. The hole was initially drilled to a depth of 2944 feet, a depth just above the
major Fruitland coal section. The hole was filled with fluid and logged. The hole was
then cased and cemented and an additional 226 feet of hole was drilled through the
Fruitland coal section. FMI log coverage was limited to the upper section of the hole
(324’ to 2943’). Two separate sonic scanner runs provided coverage from 285’ to 3156’.
The top of the Fruitland Formation was encountered at a depth of 2826 feet subsurface.
FMI log observations provide information on fracturing to within a few feet of the Upper
Fruitland Coal, which was encountered at a depth of 2963 feet subsurface.
Fast Shear Azimuth: Fast shear directions measured by the sonic scanner along the
entire length of the borehole reveal a major peak in the northeast quadrant with a vector
mean orientation of N37E (Figure 14A). The 95% confidence limit about the mean is
approximately 1 degree. Secondary peaks in the northwest and northeast quadrants have
vector mean orientation of N57W and N14E, respectively (Figure 14A). Within the
upper part of the Fruitland Formation logged in the first drilling run (2826 to 2943) the
fast shear directions form two clusters (Figure 14B) with mean trends of N64W and
N08E. In the lower coal bearing Fruitland Formation (2943 to 3132 feet) logged in the
second run, the fast shear direction has little variability about a mean orientation of N14E
(Figure 14C). The fast shear direction appears to be fairly weak and variable through the
upper Fruitland where it drifts from NW to N and then NE directions down the hole. All
distributions are significantly non-random at an -level of 0.001. The 95% confidence
limit on the mean fast-shear azimuth in the lower Fruitland coal section is less than 1
degree.
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Wilson et al. RDS Final report – March 2010
A)
B)
C)
Figure 14: A) The fast shear direction determined from the Schlumberger sonic scanner
over the entire length of the hole (275 to 3132 feet) is dominated by a cluster in the
northeast quadrant with mean orientation of N43E degrees (N=4567). Smaller peaks are
observed at approximately N14E (N=1061) and N57W (N=500). B) Within the upper
part of the Fruitland Formation, peaks are observed at N64W (N=115) and N08E
(N=118); C) In the coal bearing section the average fast shear direction is N14E (N=379).
Drilling induced breakouts: Drilling induced breakouts observed in the FMI log
through the upper Fruitland from 2826 to 2943 feet (N=5) have a vector mean orientation
of N57W (Figure 15) and 95% confidence limit of 10 degrees. The vector mean
orientation of all breakouts identified in the FMI log (N=97) is also N57W (95%
confidence limit of 3.6 degrees). Breakout orientation is generally consistent along the
entire length of the borehole. The shallowest breakout was interpreted at 329 feet and the
deepest observation made at 2936 feet. The drilling induced breakouts and fast shear
direction provide independent measures of the maximum compressive stresses in the rock.
The breakouts form normal to the present-day in-situ maximum compressive stress. The
N57W breakout trend implies a maximum compressive stress (H) of N33E. The fastshear azimuth generally lies parallel to the present day maximum compressive stress and
its value of N37E (95% confidence limits of  1 degree) is similar to the N33E (95%
confidence limits of  3.6 degrees) value inferred from the breakout orientations.
A)
B)
Figure 15: Drilling induced breakouts observed in the FMI logged interval (324 to
2943 feet) have mean trend of N57W (N=97). Those within the upper part of the
Fruitland (2826 to 2943 feet) also have mean trend of N57W (N=5).
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Wilson et al. RDS Final report – March 2010
In contrast, the fast-shear direction observed in the Fruitland coal section, taken by itself,
has a more northerly (N14E) trend. The orientations of coal face cleats observed in the
GRI NEBU well about 7 miles east of the injection well have approximately N35E trend
(Mavor and Close, 1989). The breakout orientations and fast shear directions in the strata
overlying the Fruitland Formation are consistent with that trend; however, the rotation of
the fast-shear direction to the NE within the lower coal bearing section suggests some
possibility that the face cleats may have more northerly trend at the pilot site.
Open fractures: A total of 48 open fractures were interpreted in the FMI log (Figure
16A). Although three clusters appear in the open fracture trends: N63W, N01E and N67E;
the low value of R suggests randomness in distribution. From an interpretive perspective,
preferred orientations appear to be forming in the distribution, but the number of
observations is too low to suggest definitive geological relationships.
A)
B)
C)
Figure 16: A) Open fracture trends interpreted in the FMI log from 1000 to 2905 feet in
the borehole (N= 48); B) open fractures in the Kirtland Shale primary seal (N=21); C) a
limited number of open fractures (N=5) in the upper Fruitland (2830 to 2905) have mean
orientation of about N11E.
The orientations of open fractures in the Kirtland Shale are not statistically different from
a random distribution; however, a mode appears to begin taking form with approximate
N65E trend. A limited number of open fractures (N=5) observed in the FMI log in the
upper Fruitland Formation have vector mean strike of N11E similar to the fast shear
orientation inferred from the sonic scanner in the Fruitland Formation. Taken separately
from the total, this subdivision of fractures is significantly non-random with  level of
0.01 and a 95% confidence interval of 19 degrees. The top of the Upper Fruitland Coal is
reported at 2963 feet; however, a significant coal fraction is encountered at
approximately 2948 feet where the density drops to about 1.8 gm/cm3. The FMI log
provides fracture interpretations only down to about 2943 feet, 20 feet above the Upper
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Wilson et al. RDS Final report – March 2010
Fruitland Coal. The fast-shear direction rotates to N14E in the Fruitland coal section and
suggests possibility of a rotation in the residual stress field within the Fruitland
Formation. Instability in the fast-shear measurements in the upper 100 feet of the
Fruitland Formation suggests transition in residual stress from N37E to the N14E. We
speculate that the open fractures observed in the well may have formed in response to
late-stage Laramide compression. The late-stage compression may have produced some
detachment in the coal section.
Equal area projections of open fractures observed in the injection well reveal almost
random distribution of poles as suggested in the analysis of fracture strike (Figure 17)
particularly for the total set of open fractures and those observed in the Kirtland Shale
(Figures 17 A and B). The set of open fractures observed in the upper Fruitland is small
and in this case also supportive of a northeasterly preferred trend (Figure 17C).
A)
B)
C)
Figure 17: Equal area (Schmidt Net) projections of poles to open fracture planes. A) Al
open fractures; B) open fractures observed in the Kirtland Shale; and C) open fractures
observed in the upper Fruitland Fm.
Fracture Aperture: Schlumberger’s FMI log analysis includes computation of the
hydraulic electrical apertures. Fracture aperture distribution is an important fracture
property critical to flow simulation. We prefer to use the electrical aperture as opposed to
the hydraulic aperture. Hydraulic aperture is in itself a simulation of flow, with the
assumption that the liquid is water. Running the reservoir simulation using the physical
(electrical) aperture is better then using the hydraulic aperture. The electrical aperture
(Figure 18A) is a calculated mean aperture along the fracture trace interpreted in the FMI
log. The mean aperture of that largest fracture is 0.31 inches. This is a continuous fracture
that cuts across a borehole breakout. As the aperture calculation goes along the sinusoid
and crosses the broken-out area the aperture "blooms" out into the conductive breakout.
This yields an anomalously high calculated mean aperture. The influence of these
anomalously high apertures is compounded when they are cubed to obtain hydraulic
aperture (Figure 18B). Another outlying fracture is complicated by breakout along its
trace. The hydraulic aperture distribution contains several fractures with apertures larger
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Wilson et al. RDS Final report – March 2010
than 0.3 inches. The largest electrical aperture is about 0.31 inches and considerably less
than the equivalent hydraulic aperture of 0.76 inches. The average hydraulic aperture is
0.137 inches compared to an average of 0.084 inches for the electrical aperture. The
frequency distributions of electrical and hydraulic aperture are both positively skewed.
The electrical aperture distribution is more compact. The standard deviation of electrical
apertures is
0.06inches compared to a standard deviation of
0.14 for the hydraulic
apertures.
We also examine aperture distribution for log normal behavior. Log normal
aperture distributions were reported by Bianchi (1968) in outcrop and Snow (1970) (also
see Barton and Stephansson, 1990). Electrical and hydraulic aperture distributions
observed in the injection well are plotted on logarithmic scale (Figure 18C and D) for
comparison. Results from the chi-square test for goodness of fit to the normal distribution
indicate that the distributions of log apertures (both electrical and hydraulic) do not differ
significantly from the normal distribution. The chi-square test also indicates that both log
electrical and log hydraulic aperture do not differ significantly from each other. The mean
log electrical aperture is -1.21 with standard deviation of 0.39. The mean hydraulic
aperture is -1.06 with a standard deviation of
0.43.
Figure 18: Hydraulic electrical fracture aperture distribution. N=48.
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Wilson et al. RDS Final report – March 2010
Healed Fractures: A total of 57 healed fractures were identified in the FMI log
interpretation. They were encountered from depths of 370 feet to 2925 feet subsurface.
The orientations of healed fractures appear to be more widely scattered (Figure 18A) than
the open fractures (Figure 16A) penetrated by the wellbore. As with the open fractures,
the -value is low and these differences are largely attributed to random scatter. The
orientations of healed fractures interpreted in the Kirtland Shale (Figure 19B) show some
tendency for preferred orientation at  =0.1. A mode with approximate N45W trend
emerges from the background. Healed fractures along the length of the borehole were
distributed with similar frequency from depths of 370 feet to the top of the Fruitland
Formation at 2826 feet subsurface. A relatively large number of healed fractures (14 or
about 25%) were observed in the upper 100 feet of the Fruitland Formation (Figure 20C).
The  -value for these fractures taken separately is also quite low, again suggesting t8at
the orientations are effectively random in distribution. Modes appear to emerge along
trends consistent with tectonic in-situ strains inferred from the drilling induced breakouts
and fast-shear directions. Mean azimuths of the three modes observed in the full sample
(Figure 19A) occur at N53W, N14E and N59E. Peaks in the rose diagram of healed
fractures in the upper Fruitland (Figure 19C) occur at N66W, N03W, and N50E, with
confidence limits of 11 degrees, 14 degrees and 21 degrees, respectively. With exception
of healed fractures in the Kirtland shale (Figure 19B), modes observed in these
distributions could arise at random.
A)
B)
C)
Figure 19: A) Healed fracture trends interpreted in the FMI log from 370 to 2925 feet in
the borehole (N=57); B) Healed fractures observed in the Kirtland Shale (N=17); C)
Healed fractures (N=14) in the upper Fruitland Formation.
v. Vertical Seismic Profile
The VSP surveys were completed on June 3rd and 4th. The pre-injection surveys included
a zero offset survey acquired on June 3rd, and three offset VSPs acquired the following
20
Wilson et al. RDS Final report – March 2010
day. Source point locations are shown in Figure 20. The sources have the following
locations relative to the injection well.
A Elevation 0 Ft. Offset 114 Ft. Azimuth 245 Deg.
B Elevation 47 Ft. Offset 1498 Ft. Azimuth 216 Deg.
C Elevation -27 Ft. Offset 1693 Ft. Azimuth 34 Deg.
D Elevation -62 Ft. Offset 1942 Ft. Azimuth 349 Deg.
The locations of VSP sources A through D are shown on Figure 20.
The monitor surveys were acquired in mid September of 2009. CO2 injection ceased
Figure 20: Base map showing locations of various experiments on the site. VSP offset
source locations are shown as bright green squares.
21
Wilson et al. RDS Final report – March 2010
A comparison of the baseline and monitor VSP upgoing wavefield with NMO correction
is shown in Figure 21.
A)
B)
C)
Figure 21: A) Baseline; B) post injection monitor survey; C) difference
Time lapse processing is still in progress. Although great care was taken to repeat the
initial acquisition conditions, considerable difference was observed throughout the data
set. Cross-equalization process was applied to minimize these differences. The cross
equalization operator was designed in a window extending from about 700 feet to 2600
feet subsurface. The design gate lies above the Fruitland coal section. FY10 work plans
include continued VSP analysis and interpretation.
22
Wilson et al. RDS Final report – March 2010
Michigan Basin Effort
In late FY07 and early FY08, we were asked to conduct an evaluation of the Michigan
basin pilot site, Ostego County, Michigan along the Silurian Reef trend. After
considerable background study, we discovered an independent study that was underway
at the pilot conducted as an EGR operation through Core Energy in the deeper Niagaran
reef trend. Schlumberger in cooperation with Core Energy had acquired a 3D seismic
data set over the reef complex with a focus on eventual 4D seismic evaluation of the
reservoir response to CO2 injection. A paper by Toelle et al. (2007) provided some
interesting perspectives on well history in the area that are pertinent to possible leakage
of CO2 injected by the MRCSP into the shallower Bass Island Formation. The wells
noted in Toelle’s study are shown in Figure 22.
Figure 22: Structure on the Antrim showing the location of key wells in the Toelle et al.
(2007) study. The grid of adsorption sample locations is shown by the green dots.
23
Wilson et al. RDS Final report – March 2010
Toelle et al. (2007) specifically mentioned the Charlton 4-30 as the location of the
injection point for the Bass Island sequestration test. They indicated that the well was
expected to become available for operation in the deeper Niagaran reef following CO2
injection. This well serves purposes that went beyond the objectives of the MRCSP. It’s
original use was for EGR in the Silurian Reef. Toelle et al. (2007) noted that corroded
casing was commonly encountered in all wells. The reasons for the inadvertent flood
resulted from disposal of produced water in the shallower Dundee Formation. The result
was that water had been indirectly injected into the deeper Niagaran. The 2-30 well
(Figure 22) began to produce water in 1985. 100% water cut arrived at the C2-30 well in
1997 ending primary production in the field. Appearance of CO2 in the Charlton 1-30
well injected from the end of the C2-30 lateral indicates a nearly east-west connection
between these two points (see Figure 23).
Figure 23: The locations of the C2-30 injection point and surface points are shown. CO2
from the C2-30 was observed in the 1-30 well.
24
Wilson et al. RDS Final report – March 2010
Core Energy injected CO2 into the Niagaran through the deviated C2-30 well and
temporarily produced oil from the 1-30 well to the north. The plan was to produce from
the 1-30 well until it began cycling unacceptable amounts of CO2. At that point, the 1-30
well would be converted to an injection well with the idea of pushing the remaining oil to
the south. The history of the 1-30 included 5 months of water production with no oil. The
well began to produce CO2 in the production stream only a month after oil production
occurred.
Figure 24: Suggestions for additional CATS locations. Note that the NETL MMV team
had already decided to monitor some of these points.
Based on the history of well corrosion, water dumping and inadvertent flooding of the
deeper Niagaran Reef in the area we made revised recommendations for CATS
placement in late 2007. Revised positions are shown in Figure 24. Given the history of
significant casing corrosion, CATS placements were recommended near wells noted in
the study by Toelle et al. (2007). Although at some distance, the presence of well
25
Wilson et al. RDS Final report – March 2010
corrosion along with interconnection over a distance of approximately 1 km would make
this a good location to monitor.
The outgrowths of these investigations allowed us to establish a collaborative effort with
Schlumberger through Brian Toelle (manager of Schlumberger’s DCS efforts in
Pittsburgh, PA). We are currently in the process of evaluating the 3D seismic data (Figure
25). This will be an important addition to the study. Analysis of the 3D seismic data
should provide additional insights into the CO2 sequestration issues along the Silurian
Reef trend that stretches through much of northern Michigan.
Figure 25: Inline and crossline views of 3D seismic data from the Michigan Basin Ostego
County Pilot. The base of the injection zone and the Niagaran reef interval are shown.
vi. Remote Sensing Spectral Analysis of the San Juan Injection Site
(Warner)
A wide variety of imagery has been collected over the site. The injection site is
characterized by surface disturbance particularly that associated with coal-bed methane
gas exploitation. A search was made of the USGS online archive to identify aerial images
that might document the site before the current disturbance. Imagery purchased for the
study included black and white aerial imagery, ASTER (Advanced Spaceborne Thermal
Emission and Reflection Radiometer) and Hyperion (EO-1 satellite hyperspectral) data.
Field spectra were collected on two site visits, one June 23-26 2006, and a second one
October 18-20 2006. The second visit was undertaken because after the first set of data
was collected, the proposed injection site was moved to the valley location. Just before
the second site visit the proposed site was moved a third time. However, we continued
on with the planned site visit because soil gas data had already also been collected for the
site. Thus, this data was seen as a useful pilot project. At each sampling site, spectra
26
Wilson et al. RDS Final report – March 2010
were collected of the six cover classes: soil, sandstone, shale, sagebrush, pinyon pine,
and juniper. Not all cover types were present at all sample sites, but of the cover types
present, between 3 and 6 reflectance spectra were collected of each class. In addition to
the systematic spectral collection, spectra were collected of some dead vegetation
samples to provide input for the unmixing analysis. Each site and cover type was
photographed to provide a permanent visual record of the information obtained.
Mineral Spectral Analysis
The spectra of sandstone rocks from the San Juan injection site appear to be dominated
by montmorillonite and hematite. Quartz and feldspar have relatively flat spectra and
therefore do not contribute additional absorption features.
The soils spectra, when grouped by ethane concentration in the soil gas at 100 cm, were
relatively similar. Like the sandstones, from which the soils were likely derived, the
spectra are dominated by montmorillonite and kaolinite. There is no evidence in the
spectra of the presence of minerals typically associated with hydrocarbon induced
alteration, such as kaolinite, illite or calcite.
Analysis of Vegetation Spectra
The two coniferous species, juniper and pinyon pine, have very similar spectral
reflectance curves. Sagebrush has a consistently brighter response at all wavelengths,
and a somewhat different spectra shape in the visible, especially in the blue.
Red edge position was not significantly correlated with soil gas concentration for any of
the data sets. The strongest correlation was for juniper, with an r2 of 0.25. The sagebrush
dataset had few samples with high gas concentrations, so the lack of any trend for this
species is perhaps understandable. However, when all the data are combined, there is
also no trend (r2 = 0.10).
This study evaluated the correlation of the red edge location of vegetation reflectance
with ethane, methane and a normalized and combined ethane and methane measure.
Only a weak association was observed, with r2 values varying from 0.00 to 0.25. When
the samples were grouped, the r2 was 0.10. The lack of correlation between the soil gas
values and the red edge position is probably a result of the relatively low values of soil
gas observed. It is possible that greater concentrations of hydrocarbons are required
before an effect on vegetation is observable. For example, Bammel and Birnie (1994),
who studied sagebrush response to hydrocarbon seeps in the Bighorn basin of Wyoming,
concluded that relatively high concentrations of hydrocarbons were required in order to
produce spectral changes that could be detected remotely. It should also be noted that
most previous studies have looked at regional trends, rather than local trends, as was the
case in this study. It is therefore possible that more consistent results would be found if
the scale of analysis were extended over several orders of magnitude of area. However,
this would not contribute aims of this project, which is focused on only a local region.
27
Wilson et al. RDS Final report – March 2010
Hyperspectral image analysis
Given the low signal to noise of the Hyperion data, and the challenge of unmixing
hyperspectral imagery, the results of the study suggested that hyperspectral unmixing is
potentially a useful method for dealing with mixed pixels, and that field data can be used
to parameterize the unmixing.
For all classes, except sandstone/soil, the unconstrained model was more successful than
the constrained in predicting the overall class abundances in the image. The absolute
class error was also smaller for unconstrained unmixing for all classes, with the exception
of the sandstone/soil and shale classes, although in this case the difference was very small.
The absolute class error varied from 6.7% (shale) to 18.5% (sagebrush) for constrained,
versus 6.7% to 28.7% for those same classes for unconstrained unmixing. In terms of
class RMSE, only sandstone/shale was better for constrained unmixing. For this metric,
shale was again the most accurately estimated class, with error varying between 9.4%
(unconstrained) and 10.3% (constrained), and sagebrush the worst, with errors of 25.7%
(unconstrained) and 33.6% (constrained). Finally, in terms of average class error, dead
vegetation and pinyon/juniper were generally overestimated, and sagebrush
underestimated. Errors were generally smaller for the unconstrained than the constrained
unmixing, with the exception once again for sandstone/soil, for which the constrained
algorithm had negligible error, unlike the unconstrained method.
The unmixing results indicated an average RMSE of approximately 20%. Considering
that in conventional “hard” multispectral classification, where only a single class is
predicted and a 20% error is often found, this result is regarded as encouraging. With
higher signal to noise data (for example, with the airborne sensor, AVIRIS), even higher
accuracies can be anticipated. These results also suggest that the scaling from field data
to satellite imagery is possible for this site. However, it should be considered that the
classes unmixed in this experiment were particularly distinctive. To unmix minor classes,
for example different mineral species that comprise only a portion of the soil, a much
higher signal to noise ratio would be required to obtain the same accuracy as in this study.
Adding the additional information that the proportions should sum to 1.0 (i.e. the
constrained method) was expected to be more accurate than the unconstrained method. It
was not clear why the converse was generally found. Additional research should
probably be carried out to check this result in other studies.
vii Hydrogeologic Studies (Rauch)
The hydrogeologic studies are presented in Appendix 1 (go to page 45).
viii. Conclusions
3D Seismic study: Seismic interpretation of about 9 square miles of 3D seismic data
centered around the injection well reveals that the late Cretaceous Fruitland Formation
forms a well defined seismic sequence with high amplitude reflections marking the top
and base of the sequence. Internal reflection patterns suggest considerable stratigraphic
complexity in the Fruitland Formation depositional systems. The lower Fruitland coal
reflection events are fairly continuous across the site whereas the middle and upper
28
Wilson et al. RDS Final report – March 2010
Fruitland coal events are fairly discontinuous and difficult to correlate through the
surrounding area. The detailed seismic view also reveals considerable local structural
complexity not generally observed in well log derived cross sections. The overlying
Kirtland Shale is considered to represent the effective caprock for Fruitland Formation
reservoirs. Variable area wiggly trace displays illustrate the stratigraphic and structural
complexity of the Fruitland sequence. Isochore (travel time difference) maps of the
Fruitland sequence and lower Fruitland coal intervals reveal considerable variability of
thickness throughout the area. Thinning of the Fruitland sequence occurs along a NW-SE
trend through the pilot site that coincides with a high in the base of the sequence.
Stratigraphic buildup and pinchout are observed in the upper Pictured Cliffs seismic
sequence. We speculate that thinning of the Fruitland sequence observed along the NWSE trend is associated with differential compaction over northwest trending shoreline
sand bodies in the upper Pictured Cliffs Sandstone and that differential compaction of the
Fruitland may enhance local fracture intensity along this NW-SE trend.
Post-stack processing of the 3D seismic was undertaken to help enhance seismic
indicators of fracturing and faulting. The output from specific post stack processing steps
is generally defined as a seismic attribute. There are a multitude of seismic attributes
including instantaneous phase, instantaneous frequency, envelope, energy, etc. In this
study we explored the potential use of a less common attribute consisting of the absolute
value of the derivative of the seismic amplitudes. An automatic gain control (AGC) was
applied to the output to help equalize attribute amplitude over short time windows. The
result of this simple process suggests the presence of considerable fracturing and minor
faulting within the Kirtland Shale caprock. Indicators for extensive fracturing and
faulting within the Fruitland sequence are much less apparent. The Schlumberger Ant
Tracking process however does delineate subtle zones of reflection discontinuity that
form clusters with approximate N50-55E trend. Similar patterns of discontinuity are
observed in the Kirtland and overlying Tertiary intervals (interpreted Ojo Alamo and
Nacimiento seismic sequences).
3D seismic coverage is critical to the assessment of site integrity. In this study, 3D
seismic analysis reveals numerous details about internal reservoir stratigraphic and
structural framework which we are unable to infer from limited borehole correlations.
Seismic attribute analysis can be used effectively to enhance subtle features in the
seismic response that may be indicative of fracture zones and faults that could jeopardize
reservoir integrity. The results of the analysis suggest that several small faults and
fracture zones disrupt overlying intervals and to less extent, the reservoir interval.
However, interpreted faults and fracture zones have limited vertical extent and major
penetrative faults have not been observed at the site.
EM surveys and model study: Approximately 70 line-kilometers of EM data were
collected across the site. Inverse models suggest the presence of a network of low
permeability (low conductivity) pathways in the near-surface sandstone at the site that
would facilitate atmospheric return of CO2 should leakage occur.
29
Wilson et al. RDS Final report – March 2010
Injection well logging: Fracture detection and mechanical properties logs helped us
extend our understanding of residual stress and fracture distribution from the near-surface
down through strata overlying the Fruitland coal injection zone. Sonic Scanner
observations, unlike those from the FMI log, were available through the injection zone.
Drilling induced breakout orientations of N57W along the length of the borehole suggest
invariant in-situ principal compressive stress direction of N33E. The average fast-shear
direction obtained from Sonic Scanner measurements over the entire length of the
borehole is N43E. The fast-shear direction is associated with stress induced or fracture
induced stress anisotropy. The fast-shear direction refers to the shear wave vibration
direction. Fracture induced intrinsic anisotropy arises through birefringence of the shear
wave into a fast-shear vibration component that parallels the maximum principal
compressive stress direction (or the dominant fracture trend) in strata surrounding the
borehole; the slow-shear direction is orthogonal to the fast-shear direction. Stress induced
anisotropy results from in-situ stress. When the fast-shear direction is evaluated over
local intervals above and within the Fruitland coal section, a transition occurs from the
average N43E trend to a N14E trend within the coal section. We speculate that this N14E
trend observed through the coal bearing intervals may be related to fracture induced
anisotropy and also imply a face cleat orientation of N14E.
A variety of open and healed fracture trends are penetrated between subsurface depths of
370 feet to 2925 feet within the upper Fruitland Fm. The distributions are marginally
non-random at best. A small set of open fractures in the upper Fruitland (N=5) are
significantly non-random with mean trend of N11E with 95% confidence interval of 19
degrees. The occurrence of these open fractures in the transition zone observed in the
fast-shear orientations within the upper Fruitland supports speculation that open fractures
and face cleats in the underlying Fruitland coal section may have more northerly trend.
VSP time-lapse survey: Baseline and post injection monitor vertical seismic profiles
(VSP) were collected at zero offset and 3 non-zero offsets. The monitor survey could not
acquired until September 17, 2009. Preliminary processing with Schlumberger is still in
progress. Interpretation and modeling of this data will be continued at West Virginia
University as part of continued collaborative efforts with NETL’s MMV team lead by Art
Wells.
Michigan Basin Study: This study represents some of the extensions of our work
outside the San Juan Basin (the focus of our original proposal). The outgrowths of this
study illustrate how the collaborative effort enhances and expands the potential of inhouse OST research efforts. Exploration of the literature revealed significant casing
leakage issues at the site and also helped us establish additional collaborative
relationships with industry. The Toelle et al. (2007) effort was undertaken independently
of the MRCSP effort. The study revealed significant issues concerning well bore integrity
in the area. In fact well bore leakage lead to inadvertent water flooding of a producing
reservoir cutting the life of the reservoir short. The study also resulted in
recommendations for placement of additional tracer samplers at the site.
30
Wilson et al. RDS Final report – March 2010
References
Ayers, W. B., Jr., and Zellers, S. D., 1994, Coalbed methane in the Fruitland Formation,
Navajo Lake area: geologic controls on occurrence and producibility; in Coalbed
methane in the Upper Cretaceous Fruitland Formation, San Juan Basin, New Mexico and
Colorado, New Mexico Bureau of Mines and Mineral Resources, Bulletin, 146, pp. 6385.
Bammel, B. H. and R. W Birnie, 1994. Spectral reflectance response of big sagebrush to
hydrocarbon-induced stress in the Bighorn basin, Wyoming. Photogrammetric
Engineering and Remote Sensing 60:87-96.
Barton, N., and Stephansson, O. (eds.), 1990, Proceedings of the International
Symposium on Rock Joints: June 4-6, Leon Norway, Taylor and Francis, Inc., 820p.
Bianchi, L., 1968, Geology of the Manitou Springs – Cascade area, El Paso County,
Colorado with a study of permeability of its crystalline rocks; M. Sc. Thesis, Colorado
School of Mines.
Donaldson, A. C., 1979, Origin of coal seam discontinuities; in Donaldson, A. C., Presley,
M. W., and Renton, J. J. (eds.), Carboniferous Coal Guidebook: West Virginia
Geological and Economic Survey, Bulletin B-37-1, pp 102-132.
Fassett, J., 1997, Subsurface correlation of Late Cretaceous Fruitland Formation coal
beds in the Pine River, Florida River, Carbon Junction, and Basin Creek gas-seep areas,
La Plata County, Colorado: U. S. Geological Survey Open File Report 97-59, 22p.
Mavor, M.J. and Close, J.C., 1989, Western Cretaceous coal seam project, evaluation of
the cooperative research area Northeast Blanco Unit operated by Blackwood & Nichols
Co., Ltd.: Gas Research Institute, GRI-90/0041.
Snow, D. T., 1970, The frequencies and apertures of fractures in rock: International
Journal of Rock Mechanics, Mineral Sciences and Geomechanics, Abstract 7, 23-40.
Toelle, B., Pekot, L., and Mannes, R., 2007, CO2 EOR from a north Michigan Silurian
reef: Procedings paper, Spcietyof Petroleum Engineers SPE-111223-PP, 6p.
Tyler, R., Laubach, S. E., and Ambrose, W. A., 1991, Effects of compaction on cleat
characteristics: preliminary observations; in Ayers, W. B., Jr., and others, 1991, Geologic
and hydrologic controls on the occurrence and producibility of coalbed methane,
Fruitland Formation, San Juan Basin: The University of Texas at Austin, Bureau of
Economic Geology, report prepared for the Gas Research Institute, GRI-91/0072, pp.
141-151.
Wray, L., 2000, Geologic Mapping and Subsurface Well Log Correlations of the Late
Cretaceous Fruitland Formation coal beds and carbonaceous shales - the Stratigraphic
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Mapping Component of the 3M Project, San Juan Basin, La Plata County, Colorado:
Colorado Geological Survey Report, 15p.
Acknowledgements
The WVU effort was performed in support of the National Energy Technology
Laboratory’s on-going research in carbon sequestration under the RDS contract DEAC26-04NT41817-6060404000. The effort was undertaken in direct collaboration with
Art Wells, NETL MMV team leader. We’d like to thank Dave Wildman and Donald
Martello, our DOE-NETL project managers, and George Koperna and Anne Oudinot,
Advanced Resources International, for their support and advice on these efforts; Brian
McPherson and Reid Grigg of the Southwest Regional Partnership for their help in
facilitating our involvement in their San Juan Basin pilot test; and Ryan Frost, Tom
Cochrane and Bill Akwari of Conoco Phillips for their help to facilitate many of the
activities on the site. We’d also like to thank Bill O’Dowd, the DOE-NETL project
manager for the Southwest Regional Partnership, for his support and advice on these
efforts and for his review comments. Tom Wilson is an Institute Fellows working with
NETL under the Institute for Advanced Energy Solutions (IAES) and appreciates the
opportunity to work jointly with research staff in the Office of Research and
Development at NETL.
2.0
TECHNICAL REPORTING
A total of 53 monthly reports were provided to RDS and NETL from September of 2005
through January of 2010. These reports provide a detailed record of ongoing results and
accomplishments.
Following is a list of publications and presentations made to date.
 Wilson, T., and Miller, R., 2006, Introduction to this special section: Carbon
sequestration/EOR: The Leading Edge, vol. 25, p1262-1263.
 May 31st, 2006: Wilson, NETL annual merit reviews.
 August 2, 2006: Rauch, Southwest Region Partnership meeting.
 November 20, 2006: Tensen and Warner, Field spectra collection in support of
reservoir integrity characterization for a coal bed methane carbon
sequestration site. Sixty First Annual meeting of the Southeastern Division of the
Association of American Geographers (SEDAAG), Morgantown, WV, November
19-21, 2006.
 April 4, 2007: Henthorn, Wilson and Wells, Annual AAPG Convention
presentation of paper titled Subsurface Characterization of a Carbon
Sequestration Pilot Site: San Juan Basin, NM is posted at
http://www.geo.wvu.edu/~wilson/netl/ HenthornWilson&Wells -07AAPG.pdf
Also visit the AAPG Search and Discovery site at http://www.searchanddiscovery
.net/ documents/2007/07047henthorn/index.htm for additional presentation
materials.
 October 1st, 2008: Wilson, T., Wells, A., Rauch, H., Strazisar, B., and Diehl, R.,
2008, Site Characterization Activities with a focus on NETL MMV efforts:
32
Wilson et al. RDS Final report – March 2010







3.0
Southwest Regional Partnership, San Juan Basin Pilot, New Mexico; 2008
International Pittsburgh Coal Conference, 16p. IPCC proceedings CD is posted at
http://www.geo.wvu.edu/~wilson/netl/Wilsonetal_IPCC_08_Session9.pdf The
poster presented at the meeting is available at
http://www.geo.wvu.edu/~wilson/netl/IPCC08PosterNETL.ppt
Wilson, T., Art Wells and George Koperna, 2009, Seismic Evaluation of the
Fruitland Formation with Implications on Leakage Potential of Injected CO2: In
the Proceedings CD of the 2009 International Pittsburgh Coal Conference,
Pittsburgh, PA, USA September 21 – 24, 11p.
The 2009 IPCC abstract is posted at http://www.geo.wvu.edu/~wilson/netl/sjb09.pdf. The conference paper is posted at http://www.geo.wvu.edu/
~wilson/netl/IPCC_09SJB_paper.pdf.http://www.geo.wvu.edu/~wilson/netl/IPCC
09PosterNETL.ppt or
http://www.geo.wvu.edu/~wilson/netl/IPCC09PosterNETL.pdf
Tom Wilson, Art Wells, Dwight Peters, Andrew Mioduchowski, Gabriela
Martinez, Jason Heath, in review, Fracture evaluation of the Southwest
Regional Partnership’s San Juan Basin Fruitland coal carbon sequestration
pilot site, New Mexico : AAPG Bulletin, 50 pages.
Wilson, T., 2009, San Juan Basin Pilot time-lapse vertical seismic profiles:
Background and need for additional analysis: presented at Schlumberger VSP
meeting, Nov. 13th, Houston. See http://www.geo.wvu.edu/~wilson/netl/
Wilson_VSPIntro.pdf
Sayers, C., and Wilson, T., 2010, An introduction to this special section: CO2
sequestration: The Leading Edge, vol 29, p148-149.
Wilson, T., Nutt, L., Smith, R., Coueslan, M., Peters, D., Wells, A., Hartline, C.,
Koperna, G., and Akwari, B., in review, Pre- and Post-injection Vertical
Seismic Profiling over the Southwest Regional Partnership’s Phase II
Fruitland Coal CO2 Pilot, Submitted for presentation at the 2010 Rocky
Mountain Section meeting of the American Association of Petroleum Geologists,
See abstract posted at http://www.geo.wvu.edu/~wilson/netl/
rmsectionaapg_abs.pdf
Weber, M., Wilson, T., Wells, A., Koperna, G., Bromhal, G., and Akwari, B., in
review, 3-D seismic interpretation of the Fruitland Formation at the
Southwest Regional Partnership CO2 sequestration site, San Juan Basin,
New Mexico: Expanded Abstract submitted for presentation at the 2010 Society
of Exploration Geophysicists’s Annual Convention, 4p.
FEEDBACK NETL/UNIVERSITY COLLABORATION EXPERIENCE
Positive experiences and strengths of the collaboration
Dr. Wilson and Dr. Rauch have participated in collaborative research efforts with
NETL’s MMV team for about 9 years now. It has been extremely rewarding. The
research is very interesting and the collaborative aspects of the effort really add a very
important dimension to academic research. The positive atmosphere of the team effort
33
Wilson et al. RDS Final report – March 2010
really cannot be over-emphasized. The collaboration takes us out of the cloisters and
opens interactions that would be very difficult to impossible to pursue individually.
Carbon sequestration studies represent the emergence of a new scientific discipline. The
pilot tests really require putting research efforts and ideas into short term action. Despite
all the delays and considerable unpredictability of pilot schedules and progress, it is an
exciting effort that puts one’s talents on the line. The research conducted in relation to
carbon sequestration pilot studies is multidisciplinary in nature. This aspect of the carbon
sequestration efforts requires frequent interactions across disciplines in the form of
weekly conference calls, for example, or technical meetings that bring together different
research groups on a project to evaluate the significance of certain data collected on a site
to the variety of research being conducted at the site. We had two meetings of this nature
regarding the well logs and the VSP processing on the San Juan basin site that were
coordinated through this contract. Another meeting coordinated through NETL was
focused on discussions of leakage and the development of realistic subsurface models
that might facilitate escape of injected CO2 to observed leakage points. These meetings
generally involved discussion of a wide spectrum of issues including well site operations,
reservoir integrity, reservoir engineering, surface tiltmeter observations, the nuances of
seismic acquisition and processing along with log interpretation, fracture analysis,
possible escape routes for injected CO2 and observed leakage patterns.
The experience has been very fruitful. The problems I’ve had the opportunity to work
with are those I never would have been able to become involved in as a solitary
researcher. This also goes for the students that have worked with me on the projects. The
projects provide unique and personally very rewarding opportunities for collaborative
research in areas of great importance to national energy and environmental interests.
Issues and problems
No problems to report.
Recommendations for Improvement
A general recommendation concerns the long standing issue of how to best interface OST
research with that of the regional partnerships and forthcoming Future Gen-type large
scale sequestration activities. CS projects funded through NETL should require that
proposed efforts attempt to demonstrate familiarity with in-house research efforts and to
suggest opportunities for integration (when appropriate) of OST research involvement.
This should be an integral part of all CS proposals. OST can opt not to be involved;
however, the proposal structure gives OST researchers the opportunity to prevent
duplication of effort as well as to ensure continued frontline development of long term
OST research initiatives and goals. We were very fortunate in the case of the Southwest
Regional Partnership to be intimately involved in nearly all phases of that partnership’s
efforts. However, I suspect this has not always been the case.
4.0
CONCLUSION
The variety of activities conducted in this 4.5 year period has been extensive. Details of
accomplishments and results are provided in approximately 53 monthly reports.
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Wilson et al. RDS Final report – March 2010
Reporting also included some quarterly reports and a final report for the Southwest
Regional Partnership. Section 1 of this final report is an inadequate representation of all
the work we’ve conducted as part of this collaborative effort. Section 1 does serve as a
sample of some of the highlights of our efforts.
Our main goal was to understand the site geology well enough to offer insights to the
MMV team for strategic placement of additional adsorption tube samplers and soil gas
monitoring locations. As noted in Section 1 site evaluation activities extended from the
surface veneer of massive sandstone capping the site mesa to 3D seismic evaluations of
the entire sequence not only down to the Fruitland but giving consideration to
depositional patterns in the underlying Pictured Cliffs. The last barrier to surface
migration of leaked CO2 at the San Juan Basin site was the massive sandstone that
capped the site mesa. If CO2 were to leak into the near surface, its final escape would
have been through permeable pathways through the massive sandstone. Extensive EM
surveys, fracture mapping and surface core sample collection helped provide feedback to
the MMV team concerning location of possible near-surface high permeability zones
within the massive sandstone.
The distribution and extent of local and field scale fracture systems also needed to be
evaluated. We incorporated field mapping, specially designed logging operations and 3D
seismic interpretation and attribute analysis to develop an understanding of subsurface
fracture systems that might influence reservoir flow, compromise reservoir integrity and
facilitate vertical CO2 migration.
We also developed and supervised time lapse VSP operations for the partnership’s San
Juan Basin pilot. This project also covered additional costs of specialized processing
needed in the time-lapse evaluation. The acoustic response of coal to CO2 injection is
poorly documented. The field test designed and implemented for this pilot effort will
attempt to resolve some fundamental issues associated with acoustic response of coal to
CO2 flooding. The monitor VSP was not collected till late in the fiscal year (FY09).
Time lapse processing is still in progress. Although great care was taken to repeat the
initial acquisition conditions, considerable difference has been observed throughout the
data set. Cross-equalization process was designed using a design gate extending from
about 700 feet to 2600 feet subsurface. The design gate lies above the Fruitland coal
section. FY10 work plans include continued VSP analysis and interpretation.
What we have demonstrated is that conducting an adequate site characterization for the
purpose of leakage detection and prediction must be flexible in approach and adaptable to
different geologic environments. This is important not only because of the variability in
geological environments but also due to the variety of different experiments being
conducted at a site that benefit from integration of geophysical and geological data
acquisition and analysis. In many instances the relevance of other activities, flow
simulation, for example, requires comprehensive characterization of the reservoir and
cover strata. Development of realistic flow simulations is not possible without accurate
geological models of the reservoir and sealing strata.
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Wilson et al. RDS Final report – March 2010
Outgrowths of our work have also resulted in refinements to further development of
analytical methods used to integrate borehole logs and seismic data for faults and fracture
networks in reservoir rock and overlying strata with an emphasis on assessing potential
leakage routes through seals and near-surface intervals. The results have helped move our
approach forward to produce discrete fracture networks for flow simulation and to
support risk assessment efforts. We continue to work with the NETL MMV team and
modelers to evaluate possible leakage risk and extend our knowledge of reservoir
properties.
5.0
COST STATUS:
Our initial budget estimate for a 3 year period extending from October 1 of 2005 through
September 30th of 2008 was for $909,098. Over the actual 4 year and 5 month period of
the contract we were able to continue our efforts for a total cost of approximately
$426,775. Expenditures came in under half that predicted. Although total expenses were
much less than originally anticipated, we were able to take advantage of several
opportunities including the funding and design of the well logging program for the
Southwest Regional Partnership’s San Juan Basin Pilot CO2 injection well in addition to
the design and funding of advanced processing for the Partnership’s time-lapse VSPs
conducted in the injection well.
The cost status reflects frequent interaction with RDS and budget adjustments made in
response to specific changes and opportunities associated with partnership activities. Our
efforts were flexible, adaptable and cost effective throughout the term of the project.
6.0
SCHEDULE/MILESTONE STATUS:
Our initial milestones (2005-2008) follow:
Year 1 – start-up
 Geological and Geophysical Characterization
 Background Geochemistry
 Groundwater Geochemistry (background study, initial well sitting, & initial
sampling and testing -later part of year 1)
 Remote Sensing (Landsat, Radarsat, preliminary spectroradiometer)
Year 2 - pre injection and initial post injection period
 Geological and Geophysical Characterization: conduct detailed studies of
microseep areas
 Background Geochemistry: focus additional sampling in microseeps
 Groundwater Geochemistry (sampling and testing, locate additional well(s) in
likely microseeps)
 Remote Sensing (compilation of spectral library including alteration spectra from
microseeps)
 Remote Sensing Proposal preparation and submission
 Remote Sensing (hyperspectral planning, acquisition & analysis)
 Preparation of manuscripts
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Wilson et al. RDS Final report – March 2010
Year 3 – post injection follow
 Geological and Geophysical Characterization as needed to help integrate studies
and prepare papers for publication
 Background Geochemistry (resample likely leakage areas)
 Groundwater Geochemistry (continued sampling for evidence of leakage)
 Remote Sensing (analysis of hyperspectral data, integration of observations from
all phases of RS study)
 Final integration of results, preparation of manuscripts
 Assessment, revise and develop basic integrated geosciences workflow with
recommendations for modification and adaptation to specific CSS environments.
Modifications
One of the things that we learned early on in the project was that the large scale
collaborative efforts taking place with the Partnerships often take unexpected twists and
turns. A revised milestone list was compiled near the end of 2007 (FY2008) to reflect
some of these changes. At this point in time we had added some additional efforts
associated with the Michigan Basin pilot, and reported milestone status on a monthly
basis to track progress through the revised SOW.
Michigan Basin
Milestone 1: Undertake a literature survey on geological and geophysical issues and prior
studies of the area (completed September 30, 2008).
Milestone 2: Develop a preliminary subsurface well log data base (September 30, 2008)
Status: We are considerably ahead of schedule on the development of the subsurface
database for the Michigan pilot area.
Milestone 3: Assess geophysical methods best suited to resolve potential leakage issues at
designated sites (July 2008). Status: Given the thick layer of glacial till that covers the
area, we feel that the potential for shallow EM methods (terrain conductivity or VLF) or
electrical resistivity methods will not yield information relevant to the existence, location
and distribution of fracture systems or faults that might facilitate migration of CO2 to the
surface. The best geophysical method to assess these issues would be seismic. Seismic
data just to the southwest of the pilot site reveal some potential for resolving features in
the Antrim to Bass Island (Figure 9).
Milestone 4: Seek bids for undertaking these surveys (August 15 2008). Status: The
nature of geophysical work to be conducted on the Michigan Basin and Cincinnati Arch
sites are items open for discussion with our NETL colleagues. Recommendations at this
point would be to focus efforts on the Cincinnati Arch area and to request supplemental
funding for such endeavors in FY09 after gaining familiarity with the nature and extent of
geophysical efforts planned by the MRCSP.
Milestone 5: Conduct preliminary remote sensing evaluation of the area using Landsat,
QuickBird and satellite radar imagery of the area. (Completed September 30, 2008)
Status: At this point, we raise the question raised above regarding the where efforts
should be concentrated: Cincinnati Arch versus Michigan Basin
Milestone 6: Undertake preliminary interpretation of industry 2D and 3D seismic data
from the site (completed September 30, 2008).
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Wilson et al. RDS Final report – March 2010
Status: A published seismic line from the area to the southwest has been located. This
seismic line is limited in extent and its exact location is unknown. Efforts to locate
additional seismic data have been unsuccessful at this point.
Milestone 7: Initiate terrain conductivity or other near-surface geophysical
characterization activities as justifiable by local geologic conditions (begin summer of
2008). Status: As noted above under Milestone 3, based on the geology of the site, which
includes a thick cover of glacial till, the applications of EM and resistivity methods will
yield little if any useable information about possible migration routes for escaping CO2.
One potential application would be to collect a grid of EM data over the site as an aid in
locating groundwater monitoring wells if the MRCSP allows them to be drilled. It seems
that with regard to the Michigan basin site injection is imminent and that there may be
little point in locating GW wells unless some background data can be obtained. This
remains an open item for discussion
Milestone 8: Make preliminary recommendations to the NETL MMV team (summer
2008). Status: Preliminary recommendations for location of additional CATS have been
made. Refer to Figure 8 and associated discussions.
Continuation of San Juan Basin Efforts
Milestone 9: Undertake basic interpretation of 3D seismic data from the area provided by
BP to the partnership. Status: Data has not been provided at the present time.
Milestone 10: Visit site during acquisition of post injection VSPs (February and June of
08, times approximate). Status: Acquisition of log and VSP data is delayed until an
additional permit form the State Historic Preservation Office can be obtained.
Milestone 11: Visit Houston to interact with analysts working on the log data (November
07) & VSP data (mid to late summer 08). Status: Delays in the drilling of the injection
well also offset this activity till the well is drilled and logged.
By the end of FY08: In the Michigan basin Milestones 1-6 were completed. We note that
Milestone 6 was achieved at no-cost. I was able to get a 3D seismic data set over the site
from Schlumberger. This data set consists of baseline and monitor surveys and future
plans include efforts to evaluate AVA response in areas of observable time-lapse
difference. Milestone 7 was removed since the geology of the Michigan basin site
indicated EM work would probably not provide the kind of information we needed. Also,
since we had obtained the 3D seismic data set from the site, acquisition of these data
were much less consequential to the project. Milestone 8 was completed.
In the San Juan basin Milestone 9 continues in progress. Milestones 10 and 11 were
completed.
End of FY09: As we continued our interactions with NETL’s MMV team, an additional
revised list of milestones was developed for FY09. The current list of milestones and
their status as we continue into FY10 are as follows.
FY09-FY10
San Juan Basin
Milestone 1: Status – complete in FY10. Integration of well log data into VSP and
fracture interpretations was initiated inFY09. The post injection VSP survey was
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Wilson et al. RDS Final report – March 2010
completed around September 19th. The FY09 effort yielded significant findings through
analysis of the 3D seismic data and development of a complete description of fracture
systems at the site. Analysis of the VSP time lapse will begin in FY10.
Milestone 2: Status – almost complete - Subcontract to undertake additional processing
of VSP (including time-lapse, AVO analysis and examination of additional offsets for
shear wave splitting and orientation). The WVU/Schlumberger contract has been
invoiced and payment has been authorized.
Milestone 3: Status – completed. Acquisition and processing of monitor VSP. The postinjection VSP survey was acquired in mid-September- 09.
Milestone 4: Status – work to be undertaken FY10. Integration of log derived synthetics,
VSP and 3D seismic. We are waiting for segy files from the VSP survey. Results from
the time lapse have delayed effort on this analysis till FY10. Continued work in this area
is proposed in our FY10 SOW.
Milestone 5: Status – almost complete. Time-lapse processing of pre- & post-injection
VSPs. I am hopeful this effort will be completed this month – December, 2009.
Milestone 6: Status – initiated, but incomplete. Undertake AVO work if time lapse
reveals positive results. Will make final decisions on this effort in FY10.
Milestone 7: Status –pending release of segy data from the VSP time lapse surveys.
Introduce changes in mechanical properties into AVO and time lapse models (initiated in
January 2010).
Milestone 8: Cancelled – NETL was not interested in coal samples from open pit mines
in the San Juan Basin for analysis in that study.
Milestone 9: Cancelled - Coordinate with those doing work on sample analysis (CT
scanner & Autolab) (as needed through FY09).
Milestone 10: Status –completed – samples were provided to Donald Gray and Hema
Siriwardane for analysis. No additional work is planned for this collaboration unless
feedback is received. Outgrowths of the EM modeling effort may be of some use to the
Tough2 modeling efforts. Additional assistance will be provided to Donald Gray and
Mitch Small if requested.
Milestone 11: Status – ongoing. Evaluate geophysical characterization of San Juan basin
pilot within the context of post-injection tracer and soil gas observations (through FY09).
Effort will continue pending FY10 funding. Continued work specified in FY10 SOW
Milestone 12: Status – ongoing. Participate in the development of a collaborative
publication of research results related to the San Juan Basin efforts (FY09). One
conference proceedings paper was presented in September. A journal paper is currently
undergoing internal review. A third paper relies on results from sorbant packet analysis
and time-lapse VSP. Effort will continue pending FY10 funding.
Michigan Basin
Milestone 13: Status – initiated and ongoing. Analyze and interpret 3D seismic data from
the Michigan Basin. Schlumberger sent log data from the site) Effort will continue
pending FY10 funding. Additional meeting with Schlumberger planned in Pittsburgh this
December 16th.
Milestone 14: Status – awaits completion of Milestone 13 and input concerning tracer
observations. Evaluate results in the Michigan basin area within the context of NETL
39
Wilson et al. RDS Final report – March 2010
post-injection tracer and soil gas observations (end FY09). Draft paper was prepared and
circulated in August, 2009.
Milestone 15: Status –Tracer data provided by Art Wells from the site has been plotted
and examined. A rough draft of a paper covering the results of our efforts on the site has
been prepared and circulated to Art Wells.
Other sites
Milestone 16: Status – Project data set has been built consisting of local well locations
and landgrid data the Russell Co., VA SECARB pilot Nino Ripepi, Southeastern
Partnership, has not been responsive to our requests for information. Evaluate potential
needs for collaborative efforts on other NETL MMV involvements and develop
proposal/budget. At this stage, it is difficult to know what work may be needed at
additional sites and whether the work would be significant or limited. Continued efforts
proposed in our FY10 SOW.
The foregoing summary tracks actual progress and identifies issues encountered along the
way that resulted in changes to or elimination of specific milestones. Monthly tracking of
milestones is available in our monthly reports.
7.0
SPECIAL STATUS REPORT
To be addressed
8.0
RECOMMENDATIONS
TASK1 (Wilson - Geophysical Characterization)
SITE1: San Juan Basin Pilot
As part of the FY10 effort, we will continue ongoing studies in the San Juan and
Michigan basins. The San Juan Basin effort is undertaken in coordination with the
Southwest Regional Partnership. The Michigan Basin effort is being undertaken
independently of the MRCSP study. We have established industry collaboration with
Schlumberger Data Consulting Services group. In collaboration with Schlumberger we
have obtained a 3D seismic data set over the site. The ongoing FY10 efforts are
specifically designed to carry forward and complete work related to NETL’s MMV
efforts on both sites.
VSP time-lapse processing has been modified. Our initial intent was to get a seismic view
of mechanical anisotropy on the interwell scale. Initial timelapse analysis of VSP
undertaken by Schlumberger was delayed until late in FY09 (September, 2009) and the
data sets will not be available for analysis until mid FY10. The costs of processing and
standard analysis were already covered in our FY09 budget. Modifications to the FY10
plan are related to registration problems encountered in the comparison of the pre-and
post monitoring data sets. Differences were widespread throughout the data. Additional
attention to registration, cross-equalization and preparation of data for filtering and filter
design all had to be modified. These efforts are currently in progress.
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Wilson et al. RDS Final report – March 2010
We also plan to make continued use of sonic scanner data in the FY10 continuation. The
Sonic Scanner is a state-of-art logging tool developed by Schlumberger Logging Services
to provide detailed information about compression and shear wave velocity. The
information from the sonic scanner is combined with other logs to provide mechanical
properties of caprock and reservoir intervals. Geomechanical simulations using tiltmeter
data were not initiated by NETL during FY09. If NETL researchers undertake such an
effort in FY10, we can provide mechanical properties for all subsurface layers to within
300 feet of the surface. The model we can put together would extend through 2900 feet of
strata including the Fruitland coal reservoir intervals.
Ongoing work is needed in FY10 to integrate various geophysical observations (logs, 3D
seismic, and time lapse VSP) acquired over the San Juan Basin pilot site and determine
whether those data can tell us where injected CO2 is distributed in the area surrounding
the injection well. During the past year log analysis and 3D seismic interpretations have
given us a much better understanding of properties associated with the caprock and
Fruitland Formation reservoir intervals. The outgrowths of FY09 efforts provide a solid
foundation for interpreting the post-injection multi-offset repeat VSP and NETL PFC
tracer and soil gas observations over the site. These are the major issues to be addressed
in the FY10 effort.
Our FY09 effort provided us with a better understanding of the reservoir and caprock
intervals. We established a synthetic tie between borehole and VSP and 3D seismic data
sets. We conducted extensive post-stack attribute analysis and developed 3D post stack
processing approaches to enhance subtle faults and fracture zones. These efforts revealed
the presence of potential faults and fracture zones in the caprock intervals and also in the
Fruitland coal (see Wilson et al., 2009; Wilson et al., in prep). The results of FY09
studies indicate increased risk that some migration into the seal immediately above the
Fruitland Formation CO2 reservoirs might occur. FY10 efforts will help integrate result of
site monitoring activities (VSP and PFC tracer monitoring efforts. FY10 activities will
help determine whether the VSP monitoring effort was capable of detecting changes in
acoustic properties associated with the CO2 injection zones as well as the presence of
changes in acoustic properties along subtle faults/fracture zones interpreted in the 3D
seismic data across the area. The PFC tracer and soil gas observations will be discussed
within the context of the expanded understanding of local site geology and potential risk
associated with interpreted faults and fracture zones at the site.
A major part of the FY10 effort involves preparation of papers discussing results of site
MMV activities. Potential FY10 publication outgrowths are referenced in the milestone
list below.
SITE 2: Michigan Basin Pilot
The Michigan Basin effort is being undertaken independently of the MRCSP. We
have established industry collaboration with Schlumberger Data Consulting Services
group. In collaboration with Schlumberger we have obtained a 3D seismic data set over
the site. Our efforts to date on the Michigan Basin effort include subsurface
characterization of the area based on existing formation top picks for wells in the vicinity
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Wilson et al. RDS Final report – March 2010
of the injection well. This effort provided a good appreciation for the near-surface
geology (upper 1500 feet) in the area.
During FY09 we undertook preliminary interpretation of the 3D seismic from the site.
We recently obtained sonic and density logs from the injection well along with several
additional logs from wells surrounding the injection well and within the area covered by
the Schlumberger 3D. Considerable work remains to establish an integrated log and 3D
seismic interpretation of the area.
In the coming year we will develop an integrated well log and 3D seismic interpretation
of the area. The results will be integrated into the NETL tracer studies from the site and a
paper will be prepared. A student was hired part time during the summer to work on the
Michigan Basin data set. His effort will be continued through FY10.
Progress on this effort was delayed due to intense activity on the San Juan Basin site.
Logs from the Michigan Basin area have only recently been provided by Schlumberger.
Given the need to complete the 3D seismic interpretation it is unlikely that we can
complete a paper till later this year or early next year (2010).
SITE 3: Russell Co. Virginia
The Russell County, Virginia pilot is undertaken as part of the SECARB efforts.
This pilot involves injection in multiple coal seams at depths ranging from 1050 to 2250
feet subsurface. Our involvement in the project to date has been minimal. One year ago
we prepared orthoimagery layout to show the locations of PFC monitors. Additional
FY10 efforts in support of this SECARB pilot will be provisionally undertaken given the
cooperation with SECARB. We would help the NETL MMV team interpret their PFC
tracer data within the context of local geology. We would begin by requesting SECARB
subsurface reports that document the work of the partnership to characterize the
subsurface geology of the area. We will also need to contact the Virginia geological
survey to get any county geologic reports describing the surface and subsurface geology
of that area. The budget includes about $2000 in supplies to cover the costs of reports and,
possibly, acquisition of imagery (satellite radar and/or QuickBird) over the area. The
possible benefits of lineament analysis for the site need to be evaluated. We will attempt
to get a new student involved on this effort during the coming year. The student would be
supported by the department through the academic year, but would need funding for the
summer of FY10. Possible undergraduate student help on the project will be sought
during the fall and spring semesters. Hourly wage for these efforts will be needed. Our
goal would be to provide an overview of the site efforts and to help develop the geologic
context for interpretation of the PFC tracer results. The majority of the effort should be
concluded by late summer 2010.
TASK 2 (Rauch - Hydrological Monitoring)
SITE1: Bozeman Montana Injection Monitoring MSU Site
Rauch is proposing that hydrogeologic monitoring research work continue in fiscal year
2010, at the MSU – ZERT experimental field site at the field site of Montana State
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Wilson et al. RDS Final report – March 2010
University, in Bozeman, Montana. Past Work: At this field site CO2 gas has been
injected into a shallow horizontal screened well, and many scientists have applied and
improved upon their CO2 gas monitoring techniques to detect the escape of injected CO2
gas. Rauch has conducted research at this field site for the past 3 years (2007 to 2009)
under NETL or RDS sponsorship. During July 2007 Rauch designed, supervised
construction of, sampled, hydraulically tested, and had chemically tested the ground
water from several shallow monitoring wells. For research work for July of 2008 and
2009, Rauch has conducted hydrogeologic monitoring work of the shallow monitoring
wells in conjunction with the U. S. Geological Survey (USGS) research team from Menlo
Park, California, headed by Yousif Kharaka. The USGS team sampled and chemically
tested shallow ground water, and conducted ground water dye tracer tests, while Rauch
monitored CO2 gas content within the well head space (vadose zone), during a 1 – 2 week
interval from July of 2008 and 2009 with USGS help.
Fiscal Year 2010 Work: Rauch proposes continued hydrogeologic research at the MSU –
ZERT field site, in a continued partnership with the USGS team, to improve upon MMV
aquifer monitoring techniques for environmental assurance during future CO2
sequestration tests. This would involve another CO2 gas injection and monitoring test
during summer 2010. The USGS team would conduct more ground water sampling and
chemical testing, dye tracer tests, and hydraulic aquifer pumping tests, on by a separate
budget partially funded by NETL. Rauch porposes to conduct new aquifer pumping tests
in concert with the USGS team, and would do well vadose gas CO2 sampling and testing
as well as direct ground water CO2 chemical testing. Also, the construction of three new
monitoring wells is requested, to expend the ground water and vadose zone network
representing preexisting wells. One new well would be a 4 - 6 inch diameter well to be
used for doing aquifer hydraulic pump testing; such aquifer testing in 2007 was not
adequate since the maximum pumping rate was restricted by the small 2 inch diameter
existing wells, and drawdown of the water table for the observation wells was only
~0.01 – 0.10 feet, creating high precision error in drawdown measurements and hence
aquifer permeability and storativity. A larger diameter new well would allow higher
pumping rates, a larger and deeper cone of depression within the water table, and the
determination of more accurate aquifer physical properties. The other two proposed new
wells would be 2 inches in diameter, and would be placed on the extreme northern side
and southern side of the test field, to allow measurement of water table depth, to better
determine the hydraulic gradient (water table slope) throughout the field test site; this was
requested by other MSU - ZERT scientists for the 2010 field season. Rauch's CO2 gas
testing would be done using Vaisala Inc. CO2 gas meter and probes, in conjunction with a
newly designed portable air chamber constructed by the USGS team (to allow air sample
dilution and more accurate testing); this would allow more accurate and extensive vadose
gas measuring of the escaping CO2 gas plume during CO2 gas injection. Rauch also
proposes the direct measurement of dissolved CO2 gas within sampled ground water,
using a device used by the bottled soda and beer industry, but never tried before, to his
knowledge, at injected CO2 geologic sequestration and monitoring sites. Such a device
would allow more frequent CO2 gas measurements of ground water, a comparison with
calculated theoretical CO2 gas concentration values based on water chemistry by the
USGS, and the determination of the degree of equilibrium between shallow ground water
and vadose zone CO2 gas content. Such information will allow better characterization of
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Wilson et al. RDS Final report – March 2010
escaping CO2 plumes at this field site, and should be helpful for future carbon
sequestration monitoring and testing at other field sites.
Relationships to Thrust Goals and NETL Mission
The efforts carried forward through this research contribute directly to the carbon
management thrust area. CO2 injection at the San Juan Basin site has just been terminated.
There is much that remains to be done as monitoring activities continue and begin to be
integrated. Our efforts on the San Juan Basin and Michigan pilots provide background
support and context for observations obtained from NETL’s MMV tracer and soil gas
observations. Our studies target characterization of the cover strata: site characterization
that extends from the reservoir to the surface with particular emphasis on the integrity of
the primary sealing strata.
The proposed FY10 effort involves continued collaboration on the CONSOL WV pilot.
We have also included participation in the SECARB Russell Co. effort.
As in last year’s statement of work, we are eager to expand out involvements with the
NETL MMV team at other Phase II and Phase III sites. Our particular interests are on
seismic characterization and monitoring of caprock and reservoir intervals. Should
additional opportunities arise we would discuss potential efforts with our NETL MMV
collaborator, Art Wells, to establish what efforts may be possible and whether they would
be facilitated by the partnerships in question. Depending on the possibilities, we would
propose support additional activities and submit a request for additional funds. The
workplans outlined above and in the following milestones represent considerable effort
and concentrated study and at present these remain our FY10 priorities.
Relationships to other projects within Thrust
These efforts have contributed to the flow simulation activities undertaken by Donald
Gray and Mitch Small. The efforts also provide considerable detailed information about
reservoir and sealing rock properties useful to geomechanical and flow simulation. The
outgrowths of our efforts are critical to long term monitoring and long term risk
assessment of CO2 sequestration sites.
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Wilson et al. RDS Final report – March 2010
Appendix 1: Adendum Report – Hydrogeologic Studies
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Wilson et al. RDS Final report – March 2010