CO 2 Storage Potential in the Mt Simon Sandstone, Western Kentucky Rick Bowersox January 22, 2008 Presentation Outline • Overview of Western Kentucky geology • Review of CO 2 storage reservoir issues in western Kentucky • Geology of the Mt Simon Sandstone • Some issues with the Mt Simon Sandstone as a CO 2 storage reservoir in western Kentucky • Alternative CO 2 storage reservoirs in western Kentucky Rough Northern Area Creek Fault System of Interest Rough Creek Graben Pennyrile Fault System Southern Area of Interest Western Kentucky Coal Field Our site evaluation needs to consider that there are at least three distinct geologic areas of interest in and adjacent to the Western Kentucky Coal Field. Depth to the Precambrian basement Western Kentucky Coal Field There are major differences in depths to potential CO 2 storage reservoirs in the project area. System Series Rock units Maquoketa Gp Upper Western Kentucky Lexington Ls Stratigraphic Units with Plattin Fm Black River Gp ? (High Bridge Gp) Pecatonica Fm CO 2 Storage Potential Joachim Dol Wells Creek-Dutchtown Fm Ordovician St. Peter Ss Middle Potential CO 2 Lower Beekmantown Fm sinks/ reservoirs Gunter Ss Caprock- Copper Ridge Dol. Knox Gp. Knox containment interval Upper Eau Claire Fm Unconformity ? Mount Simon Ss Sink or seal (depends on location) Middle Cambrian Metamorphic and ? Lower igneous rocks ( mostly seal ) Proterozoic Granite-Rhyolite Complex CO 2 Storage Issues Old Wellbore Seal Fault Migration IPCC (2005) System Series Rock units Maquoketa Gp Upper Western Kentucky Lexington Ls Stratigraphic Units with Plattin Fm Black River Gp (High Bridge Gp) ? Pecatonica Fm Reservoir Seal Potential Joachim Dol Wells Creek-Dutchtown Fm Ordovician St. Peter Ss Middle Potential CO 2 Lower Beekmantown Fm sinks/ reservoirs Gunter Ss Caprock seal Copper Ridge Dol. Knox Gp. Knox containment interval Upper Eau Claire Fm Unconformity ? Mount Simon Ss Sink or seal (depends on location) Middle Cambrian Metamorphic and ? Lower igneous rocks ( mostly seal ) Proterozoic Granite-Rhyolite Complex Fault Proximity Issues Well depths (ft) Faults and deep wells 2,500-4,000 4,000-5,000 Rough Creek Fault System 5,000-6,000 6,000-8,000 >8,000 Faults Pennyrile Fault System Western Kentucky Coal Field Faults can act as both storage reservoir seals and pathways for CO 2 leakage to shallower intervals and the surface. Old Well Bore Issues Well depths (ft) Existing wells >2,500 ft 2,500-4,000 4,000-5,000 5,000-6,000 6,000-8,000 >8,000 Faults Western Kentucky Coal Field Old well bores with inadequate abandonment are a potential leakage pathway to the surface. Geology of the Mt Simon Sandstone Wickstrom et al (2003) MIDCARB The Mt. Simon Sandstone is the deep saline reservoir being targeted for CO 2 storage in much of the Midwest. It is deepest in the subsurface and thinnest in western Kentucky. Inferred Transport of the Mt Simon and Lamotte Sandstones in the Illinois Basin and adjacent regions. (Ojakangas, 1963, Fig. 9) Mount Simon Sandstone Reservoir C A B A – Original quartz grain Western B – Quartz overgrowth Kentucky C – Porosity (blue) Makowitz and Milliken (2003, Fig. 2) Quartz-overgrowth cement forms in sandstones at temperatures >90-100 °C (>200 °F). (Bjørlykke and Egeberg, 1993) Makowitz et al. (2006, Fig. 5) Porosity development in the Mt Simon Sandstone. (Hoholick et al., 1984) CO 2 Core Flood Tests O’Connor and Rush (2005) Mount Simon Sandstone Reservoir Cutting at 6660 ft from Allied Chemical well #1 Fee, Vermillion O County, Illinois. Quartz grains (Q) with euhedral quartz overgrowth Q (O). Quartz grains are rimmed with secondary hematite cement. Dark areas between grains is smectitic 100 µm Kersting (1982, Fig. C-2) clay-lined porosity. Data from wells drilled in deeper portions of the Illinois Basin indicate that cements in the Mt. Simon Sandstone are quartz and potassium feldspar overgrowths with lesser hematite, kaolinite, chlorite, chert, and carbonate (Metarko, 1980; Hoholick et al, 1984; Makowitz and Milliken, 2003; Makowitz, 2004; Kunledare, 2005). >-14,000 Mt. Simon structure -13,000 to -13,999 -12,000 to -12,999 -11,000 to -11,999 Well 0 25 50 Miles -10,000 to -10,999 . -9,000 to -9,999 Fault -8,000 to -8,999 -7,000 to -7,999 -6,000 to -6,999 -5,000 to -5,999 . -4,000 to -4,999 . <-4000 . CALDWELL Western Kentucky Coal Field Sea level datum However in the vicinity of the Western Kentucky Coal Field the Mt Simon Sandstone is at a depth that reduces its potential for CO 2 storage. Mt. Simon Sandstone thickness > 800 ft Well data 800-700 ft 0 25 50 Miles . 700-600 ft 600-500 ft 500-400 ft 400-300 ft 300-200 ft . 200-100 ft . 100-0 ft . Western Kentucky Coal Field The Mt Simon Sandstone occurs north of the Rough Creek Graben and generally north of the Western Kentucky Coal Field. The thickest potential CO2 storage reservoir in the Mt Simon Sandstone is also where it is at its greatest depth. Depth (ft) The Exxon Jimmy Bell #1 GR - Caliper Bulk Density well was drilled on the northern margin of the 13000 Rough Creek Graben in Webster County. It encountered 750 ft of low porosity Mt Simon Sandstone at a depth of 13, 490 ft immediately above granitic basement rocks. 14000 Location Exxon Jimmy Bell #1 100 µm Cutting from 13,700 ft shows quartz grains (Q) with concave contacts due to pressure dissolution at grain Q boundaries rimmed with smectitic clays (C). Authigenic apatite crystals A (A) grew between quartz grains. C Kersting (1982, Fig. C-12) 100 µm Cutting from 14,220 ft shows microquartz (M) filling the pores between quartz grains (Q). Q M Kersting, (1982, Fig. C-7) Depth (ft) <10.8 km> Depth (ft) <13.9 KM> Depth (ft) 5 CAL 15 30 NPHI -10 5 CAL 15 30 CNC -10 5 CAL 15 0 GR 200 2 RHOB 3 0 GR 200 2 RHOB 3 0 GR 200 2 RHOB 3 7400 6600 7500 6700 6500 6400 6300 7600 K II, INC 1 BROOKS, J H Mt. Simon TD : 8,213 6800 7700 Sandstone KENTUCKY OPERATING MW, LLC 1 SHERRARD, VIRGINIA TD : 7,093 KY OPERATING, INC 1 RIORDAN, TRUMAN D TD : 8,019 Top of Mt. Simon datum Three shallower tests of Mt. Simon Sandstone Location drilled just east of the coal field suggest limited reservoir potential. Depth DT 140 40 CALI SNP DuPont #1 WDW 5 15 30 -10 GR RHOB 0 200 2 3 Core 2 Core 3 Mt Simon Core 4 Core 5 Sandstone test 2000 Mt. Simon Location Beekmantown Core 6 2500 Core 7 Core 8 Core 9 Core 10 3000 Knox Group Knox 3500 4000 The DuPont #1 WDW injection well Copper Ridge Dol. Copper was drilled near Louisville and Core 11 4500 encountered 761 ft of Mt Simon Core 12 Sandstone at a depth of 5193 ft. After 5000 Eau Claire Claire Eau 5000 testing, the Mt Simon was abandoned Core 1314 5500 and the well recompleted on injection Core 15 Mt. Mt. Simon in the Knox Limestone. Core 16 Precambrian Basement DuPont #1 WDW Although a core from this well showed low porosities averaging 5.5%, analysis of electric logs suggests that there was ~150 ft of Mt Simon Sandstone with porosity >10% in the well. There is also evidence suggesting that the Mt Simon Sandstone reservoir was damaged by fresh water injection during testing. DuPont #1 WDW, Louisville, KY, ~5730 ft Minimum Criteria for a CO 2 Storage Zone • Base of the sealing interval ≥2500 ft – Sufficient lithostatic pressure to ensure CO 2 remains in a supercritical state at ≥1070 psia and 88 °F – Sufficient sealing strata overlying the storage zone to mitigate the possibility of leakage to shallower intervals and the surface • Porous and permeable storage zone – Storage capacity of supercritical CO 2 ~10,000 T/Ac-ft for each incremental percent porosity – Greater porosity and permeability at shallower depths allow lower injection pressures and costs • Remote from geologic and man-made features that might compromise the integrity of the storage reservoir – Faults and fractured intervals – Mine shafts – Buildings Mt Simon Sandstone Reservoir Depth and Pressure www.beg.utexas.edu/environqlty/co2seq/12bmtsimon.htm Mt Simon Sandstone Porosity Porosity (%) DuPont WDW #1 Potential CO 2 Storage Interval Data sources (828 samples): Metarko (1980; 89 samples) Shebl (1985; 9 samples) Makowitz (2004; 27 samples) Kunledare (2005; 690 samples) Depth(ft) DuPont #1 WDW (13 samples) Exxon Jimmy Bell #1 Makowitz and Milliken (2003, Fig. 10A) Western Kentucky Reservoir Temperature CO 2 Solubility versus Pressure/Temperature MIDCARB www.kgs.ku.edu/PRS/publication/2003/ofr2003-33/P1-05.html The western Kentucky geothermal gradient is ~1 °F/100 ft of depth (36 measurements). In the prospective range of the CO2 storage reservoir the temperature will be ~85-140° F. Western Kentucky Reservoirs P-T Trend Western Kentucky Reservoirs Trend Water in the Mt Simon Sandstone reservoir of western Kentucky is extremely high salinity, about six times that of sea water. DuPont #1 WDW CO 2 Solubility versus Salinity MIDCARB Metarko (1980, Fig. 10) www.kgs.ku.edu/PRS/publication/2003/ofr2003-33/P1-05.html Mt Simon Sandstone Reservoir Well depths (ft) Existing wells >2,500 ft 2,500-4,000 4,000-5,000 5,000-6,000 6,000-8,000 >8,000 Faults Western Kentucky Coal Field The Mt Simon Sandstone reservoir is in an area of considerable faulting and existing oil field development Alternative Storage Possibilities • Strata outside of the Rough Creek Graben – Knox Group carbonate reservoirs – St Peter Sandstone – High Bridge Group carbonate reservoirs – Potential for re-entering, deepening, and sampling abandoned exploratory wells • Strata inside the Rough Creek Graben – Central to the Western Kentucky Coal Field – Few deep tests – Unknown reservoir characteristics – Potential for re-entering, deepening, and sampling abandoned exploratory wells Rough Northern Area Creek Fault System of Interest Rough Creek Graben Pennyrile Fault System Southern Area of Interest Western Kentucky Coal Field There are at least three distinct geologic areas of interest in and adjacent to the Western Kentucky Coal Field with potential CO 2 storage reservoirs.