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
Processors Technology Transfer WorkshopProcessors Technology Transfer Workshop
Pioneer Natural Resources, Inc., Pioneer Natural Resources, Inc., Gas Processors Association andGas Processors Association andEPA’s Natural Gas STAR ProgramEPA’s Natural Gas STAR Program
September 23, 2004September 23, 2004
Page 2Reducing Emissions, Increasing Efficiency, Maximizing Profits
Vapor Recovery Units: AgendaVapor Recovery Units: Agenda
Methane LossesMethane Losses
Methane RecoveryMethane Recovery
Is Recovery Profitable?Is Recovery Profitable?
Industry ExperienceIndustry Experience
Discussion QuestionsDiscussion Questions
Page 3Reducing Emissions, Increasing Efficiency, Maximizing Profits
Sources of Methane LossesSources of Methane Losses
Estimate 373 MMcf/yr methane lost from Estimate 373 MMcf/yr methane lost from atmospheric condensate storage tanks in atmospheric condensate storage tanks in gathering stationsgathering stations
EPA/GTI study estimates the methane EPA/GTI study estimates the methane emissions from storage tanks in the emissions from storage tanks in the processing sector to be 311 MMcf/yrprocessing sector to be 311 MMcf/yr
EF from Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990 - 2002,EF from Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990 - 2002,
AF from EIA financial reporting system (FRS)AF from EIA financial reporting system (FRS)
Page 4Reducing Emissions, Increasing Efficiency, Maximizing Profits
Types of Methane LossesTypes of Methane Losses
Flash losses - occur when condensate in Flash losses - occur when condensate in pipeline systems enters tanks at pipeline systems enters tanks at atmospheric pressureatmospheric pressure
Working losses - occur when condensate Working losses - occur when condensate levels in tanks change levels in tanks change
Standing losses - occur with daily and Standing losses - occur with daily and seasonal temperature and barometric seasonal temperature and barometric pressure variationspressure variations
Page 5Reducing Emissions, Increasing Efficiency, Maximizing Profits
Methane RecoveryMethane Recovery
Vapor recovery units capture up to 95% of Vapor recovery units capture up to 95% of hydrocarbon vapors vented from tankshydrocarbon vapors vented from tanks
Recovered vapors have higher Btu content Recovered vapors have higher Btu content than pipeline quality gasthan pipeline quality 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 pipeline to recover NGLsRe-injected into pipeline to recover NGLs Used as on-site fuelUsed as on-site fuel
Page 6Reducing Emissions, Increasing Efficiency, Maximizing Profits
Types of Vapor Recovery UnitsTypes of Vapor Recovery Units
Conventional vapor recovery units (VRU)Conventional vapor recovery units (VRU) Use rotary compressor to extract vapors out of Use rotary compressor to extract vapors out of
atmospheric pressure storage tanksatmospheric pressure storage tanks Require electrical power or engineRequire electrical power or engine
Venturi ejector vapor recovery units (EVRUVenturi ejector vapor recovery units (EVRUTMTM)) 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
Page 7Reducing Emissions, Increasing Efficiency, Maximizing Profits
Conventional Vapor Recovery UnitConventional Vapor Recovery Unit
Condensate Stock
Tank(s)
ControlPilot
Vent LineBack Pressure
Valve
SuctionScrubber
SuctionLine
Condensate Return
BypassValve
ElectricControlPanel
Electric DrivenRotary Compressor
Gas SalesMeter Run
Gas
Liquid Transfer Pump
Check Valve
Source: Evans & Nelson (1968)Sales
Page 8Reducing Emissions, Increasing Efficiency, Maximizing Profits
Venturi Jet Ejector*Venturi Jet Ejector*
High-PressureMotive Gas(~850 psig)
Flow Safety Valve
Pressure Indicator Temp Indicator
PI TI
TI
PI
(-0.05 to 0 psig)
Low-Pressure Vent Gas from Tanks(0.10 to 0.30 psig)
PI TI
Discharge Gas
(~40 psia)
EVRUTM Suction Pressure
*Patented by COMM Engineering*Patented by COMM Engineering
Page 9Reducing Emissions, Increasing Efficiency, Maximizing Profits
Vapor Recovery with EjectorVapor Recovery with Ejector
Gas to Sales@ 1000 psig
LP Separator
Oil
Gas
Compressor
Ejector
5,000 Mcf/d Gas5,000 Bbl/d Oil
900 Mcf/d
Ratio Motive / Vent = 3 = 900/300
300 Mcf/d Gas
40 psig
6,200 Mcf/d
Stock Tank
(19 Mcf/d Incr.fuel)
281 Mcf/dNet Recovery
Note: Production application example.Note: Production application example.
Page 10Reducing Emissions, Increasing Efficiency, Maximizing Profits
Example Facility for EVRUExample Facility for EVRUTMTM
Oil production:Oil production: 5,000 Bbl/d, 30 Deg API5,000 Bbl/d, 30 Deg API
Gas production:Gas production: 5,000 Mcf/d, 1060 Btu/cf5,000 Mcf/d, 1060 Btu/cf
Separator:Separator: 50 psig, 10050 psig, 100ooFF
Storage tanks: Storage tanks: 4 - 1500 Bbls @1.5oz 4 - 1500 Bbls @1.5oz reliefrelief
Gas compressor:Gas compressor: Wauk7042GSI/3stgArielWauk7042GSI/3stgAriel
Suction pressure:Suction pressure: 40 psig40 psig
Discharge pressure:Discharge pressure:1000 psig1000 psig
Measured tank vent:Measured tank vent: 300 Mcf/d @ 1,850 Btu/cf300 Mcf/d @ 1,850 Btu/cf
Page 11Reducing Emissions, Increasing Efficiency, Maximizing Profits
Emissions Before EVRUEmissions Before EVRUTMTM
COCO22 Equivalents Equivalents
Engine exhaust: Engine exhaust: 3,950 Tons/yr @ 790 Hp load3,950 Tons/yr @ 790 Hp load
Tank vents: Tank vents: 14,543 Tons/yr14,543 Tons/yr
Total CO2 equivalents:Total CO2 equivalents: 18,493 Tons/yr18,493 Tons/yr
Fuel consumption @ 9000 Btu/Hp-hr = 171 MMBtu/dFuel consumption @ 9000 Btu/Hp-hr = 171 MMBtu/d
Gas sales:Gas sales: 5,129 MMBtu/d5,129 MMBtu/d
Gas value:Gas value: $25,645/d @ $5/MMBtu$25,645/d @ $5/MMBtu
Page 12Reducing Emissions, Increasing Efficiency, Maximizing Profits
Emissions After EVRUEmissions After EVRUTMTM
COCO22 Equivalents Equivalents Motive gas required:Motive gas required: 900 Mcf/d900 Mcf/d Engine exhaust:Engine exhaust: 4,897 Tons/yr @ 980 Hp load4,897 Tons/yr @ 980 Hp load Tank vents:Tank vents: 0 Tons/yr0 Tons/yr Fuel consumption @ 9000 Btu/Hp-hr:Fuel consumption @ 9000 Btu/Hp-hr: 190 MMBtu/d190 MMBtu/d Total COTotal CO22 equivalents: equivalents: 4,897 Tons/yr4,897 Tons/yr Reduction:Reduction: 13,596 Tons/yr (73.5%)13,596 Tons/yr (73.5%) Total COTotal CO22 equivalents: equivalents: 4,897 Tons/yr4,897 Tons/yr Reduction:Reduction: 13,596 Tons/yr (73.5%)13,596 Tons/yr (73.5%) Gas sales:Gas sales: 5,643 MMBtu/d5,643 MMBtu/d Gas value:Gas value: $28,215/d @ $5/MMBtu$28,215/d @ $5/MMBtu Income increase:Income increase: $2,570/d = $77,100/mo$2,570/d = $77,100/mo EVRU cost installed:EVRU cost installed: $75,000$75,000 Installed cost per recovered unit of gas: Installed cost per recovered unit of gas: $0.68/Mcf/yr$0.68/Mcf/yr Payout:Payout: <1 month<1 month
Page 13Reducing Emissions, Increasing Efficiency, Maximizing Profits
Vapor Recovery Unit Decision ProcessVapor Recovery Unit Decision Process
IDENTIFY possible locations for VRUsIDENTIFY possible locations for VRUs
QUANTIFY the volume of lossesQUANTIFY the volume of losses
DETERMINE the value of recoverable lossesDETERMINE the value of recoverable losses
DETERMINE the cost of a VRU projectDETERMINE the cost of a VRU project
EVALUATE VRU project economicsEVALUATE VRU project economics
Page 14Reducing Emissions, Increasing Efficiency, Maximizing Profits
Criteria for Vapor Recovery Unit LocationsCriteria for Vapor Recovery Unit Locations
Steady source and sufficient quantity of Steady source and sufficient quantity of losseslosses Condensate tanks at gathering/ boosting Condensate tanks at gathering/ boosting
stationsstations Pig trap liquids tanksPig trap liquids tanks
Outlet for recovered gasOutlet for recovered gas Access to pipeline or on-site fuelAccess to pipeline or on-site fuel
Tank batteries not subject to air regulationsTank batteries not subject to air regulations
Page 15Reducing Emissions, Increasing Efficiency, Maximizing Profits
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%)
Page 16Reducing Emissions, Increasing Efficiency, Maximizing Profits
Estimated Volume of Tank VaporsEstimated Volume of Tank Vapors
Pressure of Vessel Dumping to Tank (Psig)Pressure of Vessel Dumping to Tank (Psig)
Vap
or V
ente
d fr
om T
anks
- cf
/Bbl
- G
OR
Vap
or V
ente
d fr
om T
anks
- cf
/Bbl
- G
OR
110110
100100
9090
8080
7070
6060
5050
4040
3030
1010
2020
1010 2020 3030 4040 5050 6060 7070 8080
Under 30° APIUnder 30° API
30° API to 39° API
30° API to 39° API40° API and Over
40° API and Over
Source: Natural Gas Star, Lessons Learned – Installing Source: Natural Gas Star, Lessons Learned – Installing Vapor Recovery Units on Crude Oil Storage TanksVapor Recovery Units on Crude Oil Storage Tanks
Page 17Reducing Emissions, Increasing Efficiency, Maximizing Profits
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
Page 18Reducing Emissions, Increasing Efficiency, Maximizing Profits
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
Page 19Reducing Emissions, Increasing Efficiency, Maximizing Profits
Value of Recovered GasValue of Recovered Gas
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 recovered natural gasP = Price of recovered natural gas
NGL = Value of natural gas liquidsNGL = Value of natural gas liquids
Page 20Reducing Emissions, Increasing Efficiency, Maximizing Profits
Cost of a VRUCost of a VRU
Major cost items:Major cost items: Capital equipment costsCapital equipment costs Installation costsInstallation costs Operating costsOperating costs
Page 21Reducing Emissions, Increasing Efficiency, Maximizing Profits
Cost of a Conventional VRUCost of a Conventional VRU
Capacity CompressorCaptial Costs Installation Costs O&M Costs
(Mcfd) Horsepower ($) ($) ($/year) 25 5-10 15,125 7,560 - 15,125 5,25050 10-15 19,500 9,750 - 19,500 6,000100 15 - 25 23,500 11,750 - 23,500 7,200200 30 - 50 31,500 15,750 - 31,500 8,400500 60 - 80 44,000 22,000 - 44,000 12,000
Vapor Recovery Unit Sizes and Costs
Note: Cost information provided by Partners and VRU manufacturers.
Page 22Reducing Emissions, Increasing Efficiency, Maximizing Profits
Value of Recovered NGLsValue of Recovered NGLs
1 2 3 4
Btu/gal MMBtu/gal $/gal
$/MMBtu1,
2
(=3/2)Methane 59,755 0.06 0.32 5.32 Ethane 74,010 0.07 0.42 5.64 Propane 91,740 0.09 0.59 6.43 n Butane 103,787 0.10 0.73 7.06 iso Butane 100,176 0.10 0.78 7.81 Pentanes+ 105,000 0.11 0.85 8.05 Total
5 6 7 8 9 10 11
Btu/cf MMBtu/Mcf $/Mcf $/MMBtuVapor
Compostion
Mixture (MMbtu/Mcf
)Value
($/Mcf)
(=4*6)(=(8*10)/1
000)
Methane 1,012 1.01 5.37$ 5.32 82% 0.83 4.41$ Ethane 1,773 1.77 9.98$ 5.64 8% 0.14 0.80$ Propane 2,524 2.52 16.21$ 6.43 4% 0.10 0.65$ n Butane 3,271 3.27 23.08$ 7.06 3% 0.10 0.69$ iso Butane 3,261 3.26 25.46$ 7.81 1% 0.03 0.25$ Pentanes+ 4,380 4.38 35.25$ 8.05 2% 0.09 0.70$ Total 1.289 7.51$
1 Nautral Gas Price assumed at $5.32/MMBtu as on mar 5 at Henry Hub
2 Prices of Indvidual NGL components are from Platts Oilgram for Mont Belvieu, TX, March 05,2004
3 Other NGl information obtained from Oil and Gas Journal, refining Report, March 19, 2001, p-83
Page 23Reducing Emissions, Increasing Efficiency, Maximizing Profits
Is Recovery Profitable?Is Recovery Profitable?
Peak Capacity (Mcfd)
Installation &
Capital Costs1
O & M Costs
($/year)Value of Gas2
($/year)Annual Savings
Payback
period3
(months)
Return on
Investment4
25 26,470 5,250 34,242$ 28,992$ 11 107%50 34,125 6,000 68,484$ 62,484$ 7 182%100 41,125 7,200 136,967$ 129,767$ 4 315%200 55,125 8,400 273,935$ 265,535$ 2 482%500 77,000 12,000 684,836$ 672,836$ 1 874%
1 Unit Cost plus esimated installation at 75% of unit cost2 $7.51 x 1/2 capacity x 365, Assumed price includes Btu enriched gas (1.289 MMBtu/Mcf)3 Based on 10% Discount rate for future savings. Excludes value of recovered NGLs4 Calculated for 5 years
Financial Analysis for a conventional VRU Project
Economics for various sized conventional VRUsEconomics for various sized conventional VRUs
Page 24Reducing Emissions, Increasing Efficiency, Maximizing Profits
Trade OffsTrade Offs
Conventional Conventional VRUVRU
EjectorEjector
Fuel for electricity (Mcf/yr)Fuel for electricity (Mcf/yr) 2,2812,281 __
Fuel (Mcf/yr)Fuel (Mcf/yr) __ 6,9356,935
Operating factorOperating factor 70%70% 100%100%
MaintenanceMaintenance HighHigh LowLow
Installed cost per recovered Installed cost per recovered unit of gas ($/Mcf/yr)unit of gas ($/Mcf/yr)
$1.00$1.00 $0.68$0.68
Payback (excl. maintenance)Payback (excl. maintenance) 3 to 27 months3 to 27 months <1 month<1 month
Page 25Reducing Emissions, Increasing Efficiency, Maximizing Profits
Technology ComparisonTechnology Comparison
Mechanical VRU Mechanical VRU advantagesadvantages Gas recoveryGas recovery Readily availableReadily available
Mechanical VRU Mechanical VRU disadvantagesdisadvantages Maintenance costsMaintenance costs Operation costsOperation costs Lube oil contaminationLube oil contamination ~ 70% runtime~ 70% runtime Sizing/turndownSizing/turndown
EVRU advantagesEVRU advantages Gas recoveryGas recovery Readily availableReadily available Simple technologySimple technology 100% runtime100% runtime Low maintenance/ Low maintenance/
operation /install costsoperation /install costs Sizing/turndown (100%)Sizing/turndown (100%) Minimal space required Minimal space required
(mount in pipe rack)(mount in pipe rack)
EVRU disadvantagesEVRU disadvantages Need HP Motive GasNeed HP Motive Gas Recompression of motive Recompression of motive
gasgas
Page 26Reducing Emissions, Increasing Efficiency, Maximizing Profits
Lessons LearnedLessons Learned
Vapor recovery can yield generous returns Vapor recovery can yield generous returns when there are market outlets for recovered when there are market outlets for recovered gasgas 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 Potential for reduced compliance costs can be considered when evaluating economics be considered when evaluating economics of VRU/EVRUof VRU/EVRUTMTM
Page 27Reducing Emissions, Increasing Efficiency, Maximizing Profits
Lessons Learned (cont’d)Lessons Learned (cont’d)
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
Page 28Reducing Emissions, Increasing Efficiency, Maximizing Profits
Case Study – PioneerCase Study – Pioneer
Pioneer Natural Resources USA, Inc. Pioneer Natural Resources USA, Inc. recycled vapors from 3 phase separators to recycled vapors from 3 phase separators to the plant inletthe plant inlet Methane emissions reduction = 3796 McfMethane emissions reduction = 3796 Mcf
Estimated cost incurred = $5,000Estimated cost incurred = $5,000
Total value of gas saved = $11,388 Total value of gas saved = $11,388
Page 29Reducing Emissions, Increasing Efficiency, Maximizing Profits
Vapor Recovery UnitsVapor Recovery Units
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
cost-effectivenesscost-effectiveness Exemplifies profitable conservationExemplifies profitable conservation
Page 30Reducing Emissions, Increasing Efficiency, Maximizing Profits
Discussion QuestionsDiscussion Questions
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.)?
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