Reducing Methane EmissionsDuring Completion Operations2007 Natural Gas STARProduction Technology TransferWorkshopGlenwood Springs, COSeptember 11, 2007Reducing 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 flow-through casing plug to isolate nextstage to be fracture stimulated.REPEAT for each stage (avg. 5 to 6 stages/well)Well continues to produce through the flow-through plugs untila workover rig is available to drill out the plugs.Stimulation fluids and gas areproduced while plugs are drilledout.Sand Flowback ProblemsWASHOUTGreen CompletionsTechnology used to recover gas wouldotherwise be 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 linethrough the productionequipment to insure propermetering.Water dumps to holdingtanksWater is recycled andreused for subsequentfracture stimulation jobs.Flowback Unit vesselsoperate at 275 to 300 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 75 29 46 794 307 487 61.3%2003 78 2 76 1227 31 1196 97.5%2004 251 10 241 5060 202 4858 96.0%2005 307 32 275 8070 841 7229 89.6%2006 466 40 426 10863 932 9931 91.4%Totals 1177 113 1064 26014 2313 23701 91.1%FlowbackGasRecovered(MMCF)FlowbackGasRecovered(%)ActualCompletionGasVented/Flared(MMCF)YearTotalNumber ofWellSpudsNo. of SpudsNotCompleted orCompletedWithoutFlowbackActual Numberof FlowbackCompletionsActualCompletionGas Generated(MMCF)Economics – Volume RecoveredWilliams Production Piceance BasinCompletion Gas Recovered0200040006000800010000120002002 2003 2004 2005 2006

MMCF60.0%70.0%80.0%90.0%100.0% Percent Gas Recovered, %Completion Gas ProducedPercent Gas RecoveredEconomics – Savings RealizedRecovery Cost Net Savings(M$) (MM$)2002 1.75 0.22 1.532003 7.20 0.90 6.302004 36.46 2.85 33.612005 48.73 4.85 43.882006 64.99 8.59 56.40Totals 159.13 17.41 141.72Year TotalRevenue(MM$)Flowback Revenue/Cost AnalysisEconomics – Savings RealizedWilliams Production Piceance BasinCompletion Gas Recovered0500010000150002000025000300002002 2003 2004 2005 2006

MMCFTotal Completion Gas, MMCFEstimated Completion Gas Recovered (No Improvement), MMCFTarget Opportunity to get theremaining completion gas capturedand sold.Without Green Completions anestimated 23 BCF of completiongas has been recovered and soldsince 2002.Capturing Gas During DrilloutsTypically gas is vented/flared duringdrillout procedureSolution: modular flowbackpackaged unit (Weatherford or PureEnergy)Example drillout:3,000-psi shut-in pressure1,400-psi drawdown while drilling8-12 hours for plug drill out time5,000 -15,000 MCFventing each drilloutConclusionReduces methane emissions, a potent Green HouseGas (GHG)Well completion type location and existinginfrastructure determine viability of Green CompletionTechnologiesProduced water and stimulation fluids from greencompletions are recycledReduces emissions, noise and citizen complaintsassociated with venting or flaringIncreases Economic Value AddedContactsJohn GardnerWilliams(303) 572-8413john.gardner@williams.comRobert VincentWilliams(970) 263-2702robert.vincent@williams.com