Tom Osborne, Professional Hydrologist In cooperation with ...Tom Osborne, Professional Hydrologist In cooperation with Linc Energy Operations, Inc. Casper, WY The USGS estimates that

Tom Osborne, Professional HydrologistIn cooperation with

Linc Energy Operations, Inc.Casper, WY

The USGS estimates that the PRB contains 510 billion tons of coal in place, but that 95%+ of that coal is not economically extractable by current mining technologies.

These resources, at depths of 500 to 2,000 feet below the surface, are the “deep coals” of the Powder River Basin.

Each square mile of the Powder River Basin Project area contains an average of 100 million tons of deep coal.

UCG is the process of the gasification of coal in-situ to produce a synthesis gas (syngas). UCG is a mining method that utilizes injection and production wells drilled from the surface and linked together in the coal seam. A UCG operation has four steps:

Well construction and linkage: The wells are linked or extended to form an in-seam channel to facilitate oxidant injection, cavity development and syngas flow.

Ignition: The coal seam is dried and then ignited.

Gas Production: Syngas is produced through combustion and gasification reactions.

Decommissioning: Ninety days after ignition, the gasification process will be shut down.

GasTech, Inc., 2007

Source: GasTech, Inc., 2007

Undeveloped surfaceFlat or rolling terrainNot alluvial valley floor> 500 ft coal depthCoal thickness > 30 ftAquitard thickness > =20 – 50 ftAbsence of extensive faultingAdequate hydrostatic pressure

Site selection- pressures, containmentBaseline water quality characterizationModeling- physical & water qualityEnvironmental permittingReaction rates and process modelsUIC planning and permittingUCG operation- the groundwater system

as reactor vesselUCG decommissioning

Coal seam hydraulic characteristicsAquitard characteristicsNearest overlying and underlying

aquifersGeotechnical characteristics and

subsidence potentialGroundwater chemistryEffects of UCG operations and

decommissioning

Excessive subsidence- very site specific and controllable by module design

Groundwater influx- influx is required for reactions; too much can quench process

Mixing of aquifers- subsurface subsidence could lead to cross-connections

Groundwater contamination- UCG operating pressure controlled to less than hydrostatic;

Restoration to baseline conditions

Felix

Big George

Wyodak

5-Spot Pattern of well clusters over Section:• Uppermost shallow aquifer (150-ft)• Felix Coal (250-ft)• Overburden Sand aquifer (1,050-ft)• Wyodak Coal (1,100-ft)• Underburden Sand aquifer (1,100-ft)

Four water quality sampling eventsPotentiometric maps

Three aquifers tested:

Wyodak coal, Overburden sand Underburden sand

Well Designation PumpedWellsObs

WellsT’s *

ft2/day S

Overburden Sand Aquifer 1 2 1.73 7.5E-05

Wyodak Coal Aquifer 1 4 4.3 7.65E-04

Underburden Sand Aquifer 1 2 12.8 1.1E-04

•Trend Wells-Operational Monitoring

•Excursion Wells-Compliance Monitoring

Q = 3 gpm, K = 0.15 ft/day, T = 4 ft2/day ne = 0.02

Distance from recovery point

(pumping well/gasifier)

i Groundwater velocity

MinimumCapture Time(30-foot Time-

of-Travel)

MaximumCapture Time (30-foot Time-of-Travel + 10

days)200–230 feet 0.10 0.78 feet/day 39 days 49 days

500–530 feet 0.03 0.23 feet/day 133 days 143 days

Example Calculation for Wyodak Coal Aquifer

Born in the 70’s, but the technology remained in adolescence

Grown up in Australia with Linc EnergyHighly intensive energy processHas potential to utilize coal reserves with

minimal surface disturbance and no disruption of shallow aquifers

Requires fusion of hydrogeology, process engineering and geotechnical evaluations

Linc Energy Operations, Inc, Casper, Wyhttp://www.lincenergy.com/index.phphttp://www.uwyo.edu/eori/_files/co2con

ference09/James%20Covell%20EORI_CO2_Presentation.pdf

HydroSolutions Inc: www.hydrosi.com• 406-655-9555