Williams Fork, Piceance Basin:Flowback Water Reuse – Quality andQuantityJill E. CooperEncana Oil & Gas (USA) Inc.March 30, 2011www.encana.comWilliams Fork, Piceance Basin Water StrategyPresentation OutlinePiceance Overview•Geology and Fracturing Necessities•Current Water Quality and Infrastructure•Source Inflow Volumes of Water•Outflows of Waterwww.encana.comPiceance Basin – Williams Fork•Geology•Overpressure Reservoir•3000’ Vertical Section•Shale, Sandstone, Coal Deposition•Avg Porosity 6%•Avg Permeability 7μD•Avg Water Saturation 65%•Frac Gradient 0.5-0.75 psi/ft•Frac Characteristics•Highly Naturally Fractured•High-Perm Formation Created WhenHydraulically FracturedWasatchWilliams ForkRollinsCozzetteCorcoranSegoMancosIles10,0009,0008,0007,0006,0005,0004,0003,0000 GR 200Formation NameDepth (ft)www.encana.comWhy Produced Water•Formation Needs•Proppant•High Perm Fractured Environment•Low/No Proppant•Gels•Cause Damage to Formation•Not Needed For Proppant Transport•Not Needed For Fracture Height Growth•Water•Clay Swelling Not an Issue•Very Little Fines Migration•Compatibilitywww.encana.comExample: Fracturing Fluid Composition•“Slickwater” fracturing fluid•Water: 98.9% to 99.2% (average 100,000bbl/well)•Sand (proppant): 0.7% to 1%•Other additives (combined): <0.09%•Fluid and water flowed back is either recycledand used as frac fluid (reducing fresh waterusage) or disposed of in permitted injection wellswww.encana.comFresh vs Produced Water Studywww.encana.comFlowback Water Recovery•100% Recovery over Life of Well0%10%20%30%40%50%60%70%80%90%100%0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400Hours On (Hr)

% Recovery75% Recovery in 60 DaysTypical Williams Fork Wellwww.encana.comPiceance Basin Water StrategyWater Recycling Composition•North and South Piceance operations are interconnected•Produced and flowback water taken to central water facility bypipeline (where available) or water truck•Water is treated for reuse•Solids, iron and hydrocarbon levels decreased•Stored in tanks or large facility ponds•Water is chemically treated for scaling and to break emulsions•Water reused in completions operations•Transport by pipeline or truck, within geologic basin•Disposal minimized where possible•On average 90% - 95%, of the water used in Piceance operationsis recycled; the balance is fresh water used in drillingwww.encana.comwww.encana.comwww.encana.comwww.encana.comPiceance Basin Water StrategyCurrent Infrastructure (estimates)Hunter Mesa Water Treatment Facility•40 miles of connected pipeline•2 high pressure pumps•310,000 bbl storage pond (13 million gallons ~ 40 acre-ft)Benzel Water Treatment Facility•4 Miles of connected pipeline•85,000 bbl storage pond (3.6 million gallons ~ 11 acre-ft)High Mesa Water Treatment Facility•40 miles of connected pipeline•1 high pressure pumps•208,000 bbl storage pond (8.7 million gallons ~ 27 acre-ft)Middle Fork Water Facility•17 miles connected pipeline•4 high pressure pumps•217,000 bbl storage pond (9.1 million gallons ~ 28 acre-ft)www.encana.comwww.encana.comWater Quality & TreatmentTypical Water Treatment Facility in the Industrywww.encana.comPiceance Water Basin StrategySecondary Water/Condensate/Solids Separation•Dissolved Air Flotation - Solids and hydrocarbon removal step•Oil/Water Separator – Hydrocarbon removal stepwww.encana.comPiceance Basin Challenges & OpportunitiesDissolved Air Flotation Results90% Solids Reduction50% BOD Reduction75% IronReduction80% HydrocarbonReductionwww.encana.comQuestions?