Installing Vapor Recovery Units Installing Vapor Recovery Units to Reduce Methane Losses to Reduce Methane Losses Lessons Learned Lessons Learned from Natural Gas STAR from Natural Gas STAR Small and Medium Sized Producer Technology Transfer Small and Medium Sized Producer Technology Transfer Workshop Workshop Bill Barrett Corporation, Evergreen Resources Inc, Bill Barrett Corporation, Evergreen Resources Inc, Southern Gas Association and EPA’s Natural Gas STAR Southern Gas Association and EPA’s Natural Gas STAR Program Program June 29, 2004 June 29, 2004
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Installing Vapor Recovery Units to Reduce Methane Losses
Installing Vapor Recovery Units to Reduce Methane Losses. Lessons Learned from Natural Gas STAR Small and Medium Sized Producer Technology Transfer Workshop Bill Barrett Corporation, Evergreen Resources Inc, Southern Gas Association and EPA’s Natural Gas STAR Program June 29, 2004. - PowerPoint PPT Presentation
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Installing Vapor Recovery Units to Installing Vapor Recovery Units to Reduce Methane LossesReduce Methane Losses
Lessons Learned Lessons Learned from Natural Gas STARfrom Natural Gas STAR
Small and Medium Sized Producer Technology Transfer Small and Medium Sized Producer Technology Transfer WorkshopWorkshop
Bill Barrett Corporation, Evergreen Resources Inc,Bill Barrett Corporation, Evergreen Resources Inc,Southern Gas Association and EPA’s Natural Gas STAR ProgramSouthern Gas Association and EPA’s Natural Gas STAR Program
Sources of Methane LossesSources of Methane Losses
~ 5.56 Bcf methane lost from storage tanks ~ 5.56 Bcf methane lost from storage tanks each year from small and medium sized each year from small and medium sized producersproducers
Flash losses - occur when crude is transferred Flash losses - occur when crude is transferred from containment at higher pressure to from containment at higher pressure to containment at atmospheric pressurecontainment at atmospheric pressure
Working losses - occur when crude levels Working losses - occur when crude levels change and when crude in tank is agitatedchange and when crude in tank is agitated
Standing losses - occur with daily and seasonal Standing losses - occur with daily and seasonal temperature and pressure changestemperature and pressure changes
Source: EF from Inventory of U.S. Greenhouse Gas Source: EF from Inventory of U.S. Greenhouse Gas Emissions and Sinks, AF from EIA financial reporting Emissions and Sinks, AF from EIA financial reporting system (FRS)system (FRS)
Capture up to 95% of hydrocarbon vapors Capture up to 95% of hydrocarbon vapors vented from tanksvented from tanks
Recovered vapors have higher Btu content Recovered vapors have higher Btu content than pipeline quality natural gasthan pipeline quality natural gas
Recovered vapors are more valuable than Recovered vapors are more valuable than natural gas and have multiple uses natural gas and have multiple uses Re-injected into sales pipelineRe-injected into sales pipeline Used as on-site fuelUsed as on-site fuel Sent to processing plants for recovering NGLsSent to processing plants for recovering NGLs
Types of Vapor Recovery UnitsTypes of Vapor Recovery Units
Conventional vapor recovery units (VRUs)Conventional vapor recovery units (VRUs) Use rotary compressor to suck vapors out of Use rotary compressor to suck vapors out of
atmospheric pressure storage tanksatmospheric pressure storage tanks Require electrical power or engineRequire electrical power or engine
Venturi ejector vapor recovery units (EVRUsVenturi ejector vapor recovery units (EVRUsTMTM)) Use Venturi jet ejector in place of rotary Use Venturi jet ejector in place of rotary
compressorcompressor Do not contain any moving partsDo not contain any moving parts Require source of high pressure gas and Require source of high pressure gas and
intermediate pressure systemintermediate pressure system
Criteria for Vapor Recovery Unit Criteria for Vapor Recovery Unit LocationsLocations
Steady source and sufficient quantity of lossesSteady source and sufficient quantity of losses Crude oil stock tankCrude oil stock tank Flash tank, heater/treater, water skimmer ventsFlash tank, heater/treater, water skimmer vents Leaking valve in blanket gas systemLeaking valve in blanket gas system
Outlet for recovered gasOutlet for recovered gas Access to pipeline or on-site utilitiesAccess to pipeline or on-site utilities
Tank batteries not subject to air regulationsTank batteries not subject to air regulations
Quantify Volume of LossesQuantify Volume of Losses
Estimate losses from chart based on oil Estimate losses from chart based on oil characteristics, pressure and temperature at characteristics, pressure and temperature at each location (each location (±± 50%) 50%)
Estimate emissions using the E&P Tank Model Estimate emissions using the E&P Tank Model ((±± 20%) 20%)
Measure losses using ultrasonic meter (Measure losses using ultrasonic meter (±± 5%) 5%) Measure losses using recording manometer Measure losses using recording manometer
and orifice well tester (and orifice well tester (±± 100%) 100%)
Quantify Volume of LossesQuantify Volume of Losses
E&P Tank ModelE&P Tank Model Computer software developed by API and GRIComputer software developed by API and GRI Estimates flash, working and standing lossesEstimates flash, working and standing losses Calculates losses using specific operating Calculates losses using specific operating
conditions for each tankconditions for each tank Provides composition of hydrocarbon lossesProvides composition of hydrocarbon losses
What is the Recovered Gas Worth?What is the Recovered Gas Worth?
Value depends on Btu content of gasValue depends on Btu content of gas Value depends on how gas is usedValue depends on how gas is used
On-site fuel - valued in terms of fuel that is On-site fuel - valued in terms of fuel that is replacedreplaced
Natural gas pipeline - measured by the higher Natural gas pipeline - measured by the higher price for rich (higher Btu) gasprice for rich (higher Btu) gas
Gas processing plant - measured by value of Gas processing plant - measured by value of NGLs and methane, which can be separatedNGLs and methane, which can be separated
Gross revenue per year = (Q x P x 365) + NGLGross revenue per year = (Q x P x 365) + NGL
Q = Rate of vapor recovery (Mcfd)Q = Rate of vapor recovery (Mcfd)P = Price of natural gasP = Price of natural gasNGL = Value of natural gas liquidsNGL = Value of natural gas liquids
1 Nautral Gas Price assumed at $5.32/MMBtu as on mar 5 at Henry Hub2 Prices of Indvidual NGL components are from Platts Oilgram for Mont Belvieu, TX, March 05,20043 Other NGl information obtained from Oil and Gas Journal, refining Report, March 19, 2001, p-83
1 Unit Cost plus esimated installation at 75% of unit cost2 $7.51 x 1/2 capacity x 365, Assumed price includes Btu enriched gas (1.289 MMBtu/Mcf)3 Based on 10% Discount rate for future savings. Excludes value of recovered NGLs4 Calculated for 5 years
Vapor recovery can yield generous returns when Vapor recovery can yield generous returns when there are market outlets for recovered gasthere are market outlets for recovered gas Recovered high Btu gas or liquids have extra Recovered high Btu gas or liquids have extra
valuevalue VRU technology can be highly cost-effectiveVRU technology can be highly cost-effective EVRUEVRUTMTM technology has extra O&M savings, technology has extra O&M savings,
higher operating factorhigher operating factor Potential for reduced compliance costs can be Potential for reduced compliance costs can be
considered when evaluating economics of considered when evaluating economics of VRU/EVRUVRU/EVRUTMTM
VRU should be sized for maximum volume VRU should be sized for maximum volume expected from storage tanks (rule-of-thumb expected from storage tanks (rule-of-thumb is to double daily average volume)is to double daily average volume)
Rotary vane or screw type compressors Rotary vane or screw type compressors recommended for VRUs where there is no recommended for VRUs where there is no source of high-pressure gas and/or no source of high-pressure gas and/or no intermediate pressure systemintermediate pressure system
EVRUsEVRUsTMTM recommended where there is gas recommended where there is gas compressor with excess capacitycompressor with excess capacity
Top Gas STAR Partners for VRUsTop Gas STAR Partners for VRUs
Top five companies for emissions reductions using VRUs in 2003Top five companies for emissions reductions using VRUs in 2003
Company Reduction (Mcf)
Marathon Oil Company 1,333,484Kerr-McGee Corporation 633,919Chevron 532,134Union Pacific Resources Group, Inc. 403,454Burlington Resources, Inc. 299,609Source: Natural GasSTAR Program
Chevron installed eight VRUs at crude oil Chevron installed eight VRUs at crude oil stock tanks in 1996stock tanks in 1996
Project Economics – Chevron Methane
Loss Reduction
(Mcf/unit/yr)
Approximate Savings per
Unit1
Total Savings
Total Capital and Installation
Costs
Payback
21,900 $43,800 $525,600 $240,000 <1 yr 1 Assumes a $3 per Mcf gas price; excludes value of recovered NGLs. Refer to the Lessons Learned for more information.
Profitable technology to reduce gas lossesProfitable technology to reduce gas losses Can help reduce regulatory requirements Can help reduce regulatory requirements
and costsand costs Additional value of NGLs further improves Additional value of NGLs further improves
To what extent are you implementing this To what extent are you implementing this BMP?BMP?
How can this BMP be improved upon or How can this BMP be improved upon or altered for use in your operation(s)?altered for use in your operation(s)?
What is stopping you from implementing this What is stopping you from implementing this technology (technological, economic, lack of technology (technological, economic, lack of information, focus, manpower, etc.)?information, focus, manpower, etc.)?