Reducing Methane Emissions DuringCompletion Operations2006 Natural Gas STARAnnual Implementation WorkshopHouston, TXOctober 24, 2006Reducing Methane Emissions duringCompletion OperationsAgendaObjectivesPiceance Basin WellCompletion ProcessDescriptionEquipment NeededEconomicsConclusionWilliams Production RMT – Piceance Basin OperationsObjectives:Virtually eliminate venting of natural gasproduced during new well completions.Capture produced gas and deliver to sales.Meter produced gas for revenue distributions.Ensure safety of personnel during entireprocess.Piceance Basin Well CompletionsWilliams Fork Formation – low permeability, tight,lenticular sandstone10-acre SpacingWells drilled to depths of 6,500 ft to 9,000 ft.Reservoir pressures as high as 4000 psi.Fracture stimulation required to make wellseconomical.Typically fracture stimulate 5 to 6 separate stagesper well.Piceance Basin Well CompletionsPerforate casing prior to Stage 1 – makes fracture stimulationpossibleFracture Stimulate Stage 1. Flowback until next step.Shut in well. Set casing plug to isolate next stage to befracture stimulated.REPEAT for each stage (avg. 5 to 6 stages/well)Once fracture stimulations aredone, all of the plugs are drilledout using a Workover Rig.Stimulation fluids and gas areproduced while plugs are drilledout.Drillout phase is when most of the gas is vented.Sand Flowback ProblemsWASHOUTGreen CompletionsTechnology used to recover gas that isotherwise vented or flared during thecompletion phase of natural gas well.Williams designed equipment to handlehigh pressure, high rate flowback fluids soas to safely handle and to sell the naturalgas produced during flowback period.Flowback equipment is used to separatesand, water and gas during initial flowback.Flowback UnitSand VesselGas VesselFlowback Unit - OperationSand Vesselseparates sand fromflowback liquids.Sand is dumped toreserve pit. Gas andLiquids dump to theGas Vessel.Flowback Unit - OperationGas Vessel separatesgas from water used forfracture stimulation.Gas routed to sales line.Water dumps to holdingtanks automaticallyWater is filtered andreused for future fracturestimulation jobs.Vessels operate at 275 to300 psi.RisksSafety – Primary ConcernHigh pressure gas, liquids and sand canerode steel pipe.To mitigate safety concerns:Pipe, Fittings and Vessels use high strength metalFlowback Units are monitored 24/7.Simultaneous OperationsDrillingCompletionDrilloutProductionRisksOperations & Reservoir RisksFluids pumped downhole must be recovered asquickly as possibleWellbore damage by fluids can diminish productionFlowing fluids to flowback skid results in decreasedflowback rates because of high backpressure (versusno backpressure when venting)Economics – Volume Recovered2002 751461599112 487 81.3%2003 809711348152 1196 88.8%2004 253342195635757 4878 86.6%2005 3020302671806718 100.0%2006* 4450445974009740 100.0%* - ForecastedActualCompletion GasGenerated(MMCF)FlowbackGasRecovered(MMCF)Flowback GasRecovered (%)ActualCompletionGasVented/Flared(MMCF)YearTotalNumber ofWell SpudsNo. of SpudsNot Completedor CompletedWithoutFlowbackActual Numberof FlowbackCompletionsPrior to “Green Completions” only 88% of the Completiongas was recovered.Economics – Savings RealizedVent/Flare Volumes with and without Green Completions02004006008001000120020022003200420052006*

Vent/Flare Volume, MMCFActual Vent/Flare Volume, MMCFVent/Flare without Green Completions, MMCF1.8 BCF would have beenvented/flared if GreenCompletions were not used.1.0 BCF of completiongas vented or flaredsince 2002.Economics – Savings RealizedRecovery Cost Net Savings(MM$) (MM$)2002 1.28 0.221.062003 6.32 0.895.432004 27.87 2.8525.022005 42.68 6.7235.962006* 50.06 11.38 38.68* - ForecastedYear TotalRevenue(MM$)Flowback Revenue/Cost AnalysisConclusionReduces methane emissions, a potent Green HouseGas (GHG)Well completion type determines viability of GreenCompletion TechnologiesProduced water and stimulation fluids from greencompletions are recycledEliminates emissions, noise and citizen complaintsassociated with flaringIncreases Economic Value AddedContactsGerard G. Alberts,Williams(303) 572-3900jerry.alberts@williams.comRobert Vincent,Williams(970) 263-2702robert.vincent@williams.com