Advanced Resources International 1 Washington and Oregon: Deep Coal Seam CO 2 Sequestration Potential Scott H. Stevens, Greg Bank Advanced Resources International, Inc. (ARI) Arlington, Virginia, USA October 28, 2004 WESTCARB Meeting Portland, Oregon

Advanced Resources International 2 CO 2 – ECBM Study Results 1)The NW is short on good quality “conventional” (sandstone, carbonate) depleted reservoirs for geologic sequestration. 2)Fortunately, extensive coal deposits occur in the NW, located close to industry and power generation. 3)This first CO 2 -ECBM study synthesized all available data, including confidential CBM pilot results. 4)CBM testing indicates good reservoir quality: 100 ft coal, 1,000 ft 3 /ton CO 2 sorption, 5 md permeability. 5)Good potential for CO 2 storage using Centralia power plant (1,400 MW) near Seattle-Tacoma.

Advanced Resources International 3 1.0CBM Basics

Advanced Resources International CBM Basics Coalbed methane (and CO 2 ) storage and production mechanisms differ from those of Conventional reservoirs. CH 4 and CO 2 gas is “sorbed” under pressure onto the huge surface area of coal. This makes CBM reservoirs more difficult to evaluate.

Advanced Resources International CBM Basics Left CBM is produced using: low-damage air or light mud drilling; cased hole; selective gel or water/sand frac. Water is pumped up tubing, gas flows up annulus. Right Coal mine methane (CMM) wells, uncased in- mine horizontal boreholes and surface vertical gob wells, are less productive but used for mining safety.

Advanced Resources International CBM Basics Coalbed Methane Production Produced using conventional vertical wells Water is pumped out of coal reservoir, reducing pressure and eliciting CH 4 desorption from coal. Produced at low P (~50 psia), need compression. Gas is >95% CH 4 with minor CO 2 (0-5%) Future coal mining becomes easier and safer. CBM provides nearly 10% of US natural gas prod.

Advanced Resources International USA CBM Basins Western Washington 24 Tcf Wind River 2 Tcf Greater Green River 84 Tcf Uinta 10 Tcf Piceance 84 Tcf San Juan Fruitland Coal = 50 Tcf Menefee Coal = 34 Tcf Raton 12 Tcf Arkoma 4 Tcf Warrior 20 Tcf Central Appalachia 5 Tcf Northern Appalachian 61 Tcf Illinois 21 Tcf Established CBM Basin Emerging CBM Basin Frontier CBM Basin Forest City Cherokee 17.8 Powder River 61 Tcf 9 Commercial Basins, >20,000 Wells, 29.1 Tcf Reserve Additions out of 600 Tcf of Gas in Place. Northwest undergoing pilot testing but still pre-commercial. Reserve Additions N 2 and CO 2 ECBM Pilots

Advanced Resources International 8 2.0CO 2 - ECBM

Advanced Resources International Location of ECBM Pilots San Juan Basin, USA ECBM is still “pre-commercial” but has been tested successfully in the San Juan, the world’s premier CBM basin.

Advanced Resources International Burlington Resources Allison Unit CO 2 -ECBM Pilot San Juan Basin, New Mexico

Advanced Resources International WA/OR Coal and CBM Reservoir Properties

Advanced Resources International Study Area Oregon-Washington Eocene coal region. 3 areas assessed: Bellingham Basin, northern WA: good coal development, some CO 2 sources. Puget, WA: has best ECBM potential and largest CO 2 sources. Coos Bay, OR: poor coal development and few CO 2 sources.

Advanced Resources International Regional DEM Data integrated using ArcView GIS. Digital elevation model (DEM) allows depth calculation from structure. Evaluate surface topo for access & costs. Infrastructure routes.

Advanced Resources International Evaluation Used Existing Data Coal Industry Data -Coal exploration corehole logs and core -Proximate analyses -Maceral content -Seismic -Mining data Oil & Gas Industry Data -Well logs (poor resolution for coal; coal core rare) -Mud/Gas logs -Vitrinite reflectance -Seismic (more common, better quality than coal industry) -Drilling records

Advanced Resources International Central WA : Coal Stratigraphy Coal mainly occurs in Eocene Skookumchuck, Spiketon, & Carbonado members of Cowlitz Fm.

Advanced Resources International Bellingham, WA Medium-sized coal deposit in extreme NW Wash. Distant from CO 2 sources but on pipeline routes. Minimal CBM exploration to date. Geology favorable but poor data control. Low priority area for ECBM.

Advanced Resources International Central WA Favorable geology and reservoir conditions. CBM testing has focussed here, thus good data control. Close to large CO 2 sources. Best area: See Section 5.0 for details. Centralia Carbonado Kanaskat

Advanced Resources International Coos Bay, OR Small and isolated coal deposit on OR coast. Located far from CO2 sources. Minimal CBM exploration to date. Poor data control. Low priority area for ECBM.

Advanced Resources International CO 2 Sequestration Potential

Advanced Resources International CH 4 Sorption Isotherms (WA & CAN) Sorptive capacity increases directly with coal rank. Data from El Paso pilot & nearby British Colombia coals.

Advanced Resources International CO 2 Sorption Isotherms (WA & CAN) CO 2 sorptive capacity nearly 2X that of CH 4. Data mainly from British Colombia coals.

Advanced Resources International CO 2 & CH 4 Isotherm Rank-Adjusted Linear correlation allows V L & P L adjusted by rank. Improved estimate of CO 2 storage capacity.

Advanced Resources International CO 2 -ECBM Potential Demonstration Site at Centralia

Advanced Resources International Centralia PP TransAlta’s Centralia power plant near Tacoma & Seattle. Near coal fields with CBM testing data. 1.3 Bcfd gas pipeline. 1,404-MW coal-fired (1971-2). New 248- MW gas-fired CCGT (2002) mt CO 2 emissions in 2002.

Advanced Resources International Central WA Favorable coal rank: sub-bituminous in the W to anthracite in E. El Paso Production CBM pilot tested good permeability (5 md) in coals undersaturated with methane. ARI still computing CO 2 sequestration capacity, but likely more than adequate for Centralia plant.

Advanced Resources International Central WA Coal Thickness Duncan Oil #3 well, Pierce County (28- 18N-6E) completed in Multiple coal seams dispersed over 3,000 ft stratigraphic interval. CBM well can only complete 5-6 seams using 3-4 fracs.

Advanced Resources International Central WA Coal Thickness Penetrated 19 individual coal seams, up to 10 ft thick each. 100 ft thick in total is quite favorable. But steeply dipping (15-80º).

Advanced Resources International Next Steps Complete overall NW ECBM evaluation. Consider more detailed study of Centralia site for deep coal sequestration. One of the best options for CO 2 storage in the Northwest. Seattle Tacoma Centralia Power Plant 9,400,800 MWh 2002 Emissions: 10.5 mt CO 2 Northwest Pipeline Corp 1.3 Bcfd El Paso Petroleum CBM pilots