final report of efforts undertaken through netl for the ...pages.geo.wvu.edu/~wilson/netl/rds...

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 / [email protected]

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 REPORTAn 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 summaryGeophysical 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

Wilson et al. RDS Final report – March 2010

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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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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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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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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 dip-elongate (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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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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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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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 analysisSeveral 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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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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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 CharacterizationApproximately 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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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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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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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 fast-shear 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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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 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 Fruitland Coal. The fast-shear direction rotates to N14E in the Fruitland coal section and


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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 than 0.3 inches. The largest electrical aperture is about 0.31 inches and considerably less


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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.

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.


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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 ProfileThe 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 day. Source point locations are shown in Figure 20. The sources have the following locations relative to the injection well.


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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.


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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.


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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.


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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.


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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


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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


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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 AnalysisThe 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 SpectraThe 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.


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Hyperspectral image analysisGiven 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. Conclusions3D 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


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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. 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 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.

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.


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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 in-house 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.


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ReferencesAyers, 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. 63- 85.

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.

AcknowledgementsThe WVU effort was performed in support of the National Energy Technology Laboratory’s on-going research in carbon sequestration under the RDS contract DE-AC26-04NT41817-6060404000. 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:


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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/sjb-09.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/IPCC09PosterNETL.ppt orhttp://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.

3.0 FEEDBACK NETL/UNIVERSITY COLLABORATION EXPERIENCE

Positive experiences and strengths of the collaborationDr. 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 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.


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http://www.geo.wvu.edu/~wilson/netl/IPCC09PosterNETL.pdf

http://www.geo.wvu.edu/~wilson/netl/IPCC09PosterNETL.ppt

http://www.geo.wvu.edu/~wilson/netl/IPCC09PosterNETL.ppt

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 problemsNo problems to report.

Recommendations for ImprovementA 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. 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


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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.

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


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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

Year 3 – post injection follow


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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.

ModificationsOne 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 BasinMilestone 6: Undertake preliminary interpretation of industry 2D and 3D seismic data from the site (completed September 30, 2008).


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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 discussionMilestone 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 EffortsMilestone 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-FY10San Juan BasinMilestone 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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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 post-injection 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 SOWMilestone 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 BasinMilestone 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


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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 sitesMilestone 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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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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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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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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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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Appendix 1: Adendum Report – Hydrogeologic Studies


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final report of efforts undertaken through netl for the ...pages.geo.wvu.edu/~wilson/netl/rds...

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