transmission best management practices and opportunities lessons learned from natural gas star...

Transmission Best Management Transmission Best Management Practices and OpportunitiesPractices and Opportunities

Lessons LearnedLessons Learnedfrom Natural Gas STARfrom Natural Gas STAR

Transmission Technology Transfer WorkshopTransmission Technology Transfer Workshop

Duke Energy Gas Transmission,Duke Energy Gas Transmission,Interstate Natural Gas Association of America (INGAA) and Interstate Natural Gas Association of America (INGAA) and

EPA’s Natural Gas STAR ProgramEPA’s Natural Gas STAR Program

September 22, 2004September 22, 2004

Reducing Emissions, Increasing Efficiency, Maximizing Profits

Transmission BMP: AgendaTransmission BMP: Agenda Transmission Sector EmissionsTransmission Sector Emissions Introduction to Partner Reported Introduction to Partner Reported

Opportunities (PROs)Opportunities (PROs) Selected PRO OverviewsSelected PRO Overviews DI&MDI&M Industry ExperienceIndustry Experience New Leak Detection TechnologyNew Leak Detection Technology Discussion QuestionsDiscussion Questions


Natural Gas and Petroleum Industry Natural Gas and Petroleum Industry EmissionsEmissions

Transmission sector responsible for large Transmission sector responsible for large portion of emissionsportion of emissions

Bcf = billion cubic feetBcf = billion cubic feet

EmissionsEmissionsReductionsReductions

Trans & Storage Trans & Storage 96 Bcf 96 Bcf

Production Production 149 Bcf149 Bcf

Processing Processing 36 Bcf 36 Bcf

Distribution Distribution 77 Bcf77 Bcf

26 Bcf26 Bcf

5 Bcf5 Bcf

20 Bcf20 Bcf

1 Bcf1 BcfOil Downstream Oil Downstream 2 Bcf 2 Bcf

Inventory of U.S. Inventory of U.S. Greenhouse Gas Greenhouse Gas Emissions and Sinks Emissions and Sinks 1990 - 20021990 - 2002


Transmission Sector EmissionsTransmission Sector Emissions

The transmission sector has several large The transmission sector has several large methane emission sources that can be methane emission sources that can be targeted for reductionstargeted for reductions

Pneumatic DevicesPneumatic Devices11 Bcf11 Bcf

Centrifugal CompressorsCentrifugal Compressors8 Bcf8 Bcf

Pipeline LeaksPipeline Leaks 7 Bcf 7 Bcf

Gas Engine ExhaustGas Engine Exhaust11 Bcf11 Bcf

ReciprocatingReciprocatingCompressors Compressors 40 Bcf40 Bcf

Station VentingStation Venting7 Bcf7 Bcf

Other Sources Other Sources 5 Bcf5 Bcf

Station FugitivesStation Fugitives7 Bcf7 Bcf

Inventory of U.S. Inventory of U.S. Greenhouse Gas Greenhouse Gas Emissions and Sinks Emissions and Sinks 1990 - 20021990 - 2002


Transmission & Distribution Sector Transmission & Distribution Sector Best Management PracticesBest Management Practices

BMP 1: Directed inspection and maintenance at gates BMP 1: Directed inspection and maintenance at gates stations and surface facilities stations and surface facilities

BMP 2: Identify and rehabilitate leaky distribution pipe BMP 2: Identify and rehabilitate leaky distribution pipe

BMP 3: Directed inspection and maintenance at BMP 3: Directed inspection and maintenance at compressor stations compressor stations

BMP 4: Use of turbines at compressor stations BMP 4: Use of turbines at compressor stations

BMP 5: Identify and replace high-bleed pneumatic BMP 5: Identify and replace high-bleed pneumatic devices devices

BMP 6: Partner Reported OpportunitiesBMP 6: Partner Reported Opportunities


Transmission BMPTransmission BMP

60% of the transmission sector reductions 60% of the transmission sector reductions came from PROscame from PROs

BMP3 DI&M BMP3 DI&M 21 %21 %

BMP4 BMP4 Turbines 17 %Turbines 17 %

BMP5 BMP5 PneumaticsPneumatics

2 %2 %

Wet Seals Wet Seals 16 %16 %

Fuel Fuel RecoveryRecovery

14 %14 %

PumpdownPumpdown

12 %12 %

Other PROsOther PROs

16 %16 %

Install VRUInstall VRU

2 %2 %


Why Are Partner Reported Why Are Partner Reported Opportunities (PROs) Important?Opportunities (PROs) Important?

Partner Annual Reports document Program Partner Annual Reports document Program accomplishmentsaccomplishments BMPs: The consensus best practicesBMPs: The consensus best practices PROs: Partner Reported OpportunitiesPROs: Partner Reported Opportunities

Simple vehicles for sharing successes and Simple vehicles for sharing successes and continuing Program’s future continuing Program’s future PRO Fact SheetsPRO Fact Sheets Lessons Learned: Expansion on the most Lessons Learned: Expansion on the most

advantageous BMPs and PROsadvantageous BMPs and PROs Technology Transfer WorkshopsTechnology Transfer Workshops


Why Are Partner Reported Why Are Partner Reported Opportunities (PROs) Important?Opportunities (PROs) Important?

Many transmission facilities have identified practical, Many transmission facilities have identified practical, cost-effective methane emissions reduction cost-effective methane emissions reduction practicespractices

Transmission Partners report saving 134 Bcf since Transmission Partners report saving 134 Bcf since 1993, 60% from PROs1993, 60% from PROs

Replacing wet seal with dry seals account for 16% Replacing wet seal with dry seals account for 16% of PRO emissions reductionsof PRO emissions reductions Lessons Learned study availableLessons Learned study available


Gas STAR PRO Fact SheetsGas STAR PRO Fact Sheets

43 PROs apply to transmission Sector43 PROs apply to transmission Sector 19 focused on operating practices19 focused on operating practices 24 focused on technologies24 focused on technologies

PRO Fact Sheets are derived from Annual PRO Fact Sheets are derived from Annual Reports 1994 to 2002Reports 1994 to 2002 Total 57 posted PROsTotal 57 posted PROs epa.gov/gasstarepa.gov/gasstar


Gas STAR Lessons Learned StudiesGas STAR Lessons Learned Studies

9 Lessons Learned studies are applicable to 9 Lessons Learned studies are applicable to transmission sectortransmission sector 5 focused on operating practices5 focused on operating practices 4 focused on technologies4 focused on technologies

All 16 Lessons Learned studies are on Gas All 16 Lessons Learned studies are on Gas STAR web siteSTAR web site epa.gov/gasstarepa.gov/gasstar


Lessons Learned Studies for Lessons Learned Studies for Transmission SectorTransmission Sector

Using hot taps for in service pipeline connectionsUsing hot taps for in service pipeline connections

Convert gas pneumatic controls to instrument airConvert gas pneumatic controls to instrument air

Using pipeline pump-down techniques to lower gas line pressure Using pipeline pump-down techniques to lower gas line pressure before maintenancebefore maintenance

DI&M at compressor stationsDI&M at compressor stations

Reducing emissions when taking compressors off-lineReducing emissions when taking compressors off-line

Reducing emissions from compressor rod packing systemsReducing emissions from compressor rod packing systems

Replacing wet seals with dry seals in centrifugal compressorReplacing wet seals with dry seals in centrifugal compressor

Options for reducing methane emissions from pneumatic devices in Options for reducing methane emissions from pneumatic devices in the natural gas industrythe natural gas industry

Composite wrap for non-leaking pipeline defectsComposite wrap for non-leaking pipeline defects


PRO Operating PracticesPRO Operating Practices

Rerouting of glycol skimmer gasRerouting of glycol skimmer gas

Close main and unit valves prior to blowdownClose main and unit valves prior to blowdown

Pipe glycol dehydrator to vapor recovery unitPipe glycol dehydrator to vapor recovery unit

Perform leak repair during pipeline replacementPerform leak repair during pipeline replacement

Inspect and repair compressor station blowdown valvesInspect and repair compressor station blowdown valves


Rerouting of Glycol Skimmer GasRerouting of Glycol Skimmer Gas

What is the problem?What is the problem? Non-condensable gas from the Non-condensable gas from the

condensate separator is vented condensate separator is vented Partner solutionPartner solution

Reroute the condensate separator Reroute the condensate separator gas to reboiler firebox for fuel usegas to reboiler firebox for fuel use

Methane savingsMethane savings Based on a dehydrator having a gas Based on a dehydrator having a gas

entrainment rate of 3 cf/ gallon of entrainment rate of 3 cf/ gallon of glycol and gas containing 95% glycol and gas containing 95% methanemethane

ApplicabilityApplicability All dehydrators with vent All dehydrators with vent

condenserscondensers

Methane Methane SavingsSavings

7,600 Mcf/yr7,600 Mcf/yr

Project Project EconomicsEconomics

Project Project CostCost

< $1,000< $1,000

Annual Annual O&M O&M CostsCosts

$100 - $100 - $1,000$1,000

PaybackPayback < 1 yr< 1 yr


Close Main and Unit Valves Prior to Close Main and Unit Valves Prior to BlowdownBlowdown

What is the problem?What is the problem? Main valves are closed for Main valves are closed for

maintenance practices and the gas is maintenance practices and the gas is vented to the atmospherevented to the atmosphere

Partner solutionPartner solution Close main AND unit valves AND blow Close main AND unit valves AND blow

down isolated sections of equipmentdown isolated sections of equipment Methane savingsMethane savings

Based on venting of high pressure Based on venting of high pressure equipment, large volume vessels or equipment, large volume vessels or pipeline segments to the atmosphere pipeline segments to the atmosphere during routine maintenanceduring routine maintenance

ApplicabilityApplicability All compressor stationsAll compressor stations





NoneNone


$100 - $100 - $1,000$1,000



Pipe Glycol Dehydrator to Vapor Pipe Glycol Dehydrator to Vapor Recovery UnitRecovery Unit

What is the problem?What is the problem? Methane gas from glycol dehydrator Methane gas from glycol dehydrator

is vented to the atmosphereis vented to the atmosphere Partner solutionPartner solution

Reroute vented gas to Vapor Reroute vented gas to Vapor Recovery Unit (VRU)Recovery Unit (VRU)

Methane savingsMethane savings Based on an electric or energy Based on an electric or energy

exchange circulation pump, can exchange circulation pump, can recover 3 to 9 Mcf of methane per recover 3 to 9 Mcf of methane per MMscf of gas processedMMscf of gas processed

ApplicabilityApplicability No limitations when the VRU No limitations when the VRU

discharges to fuel gas or main discharges to fuel gas or main compressor stationcompressor station





$1,000 - $1,000 - $10,000$10,000


> $1,000> $1,000



Perform Leak Repair During Pipeline Perform Leak Repair During Pipeline ReplacementReplacement

What is the problem?What is the problem? Corrosion and debris in pipelines Corrosion and debris in pipelines

accumulate in valve seats, preventing accumulate in valve seats, preventing tight closures and causing emissions tight closures and causing emissions during isolation of pipelinesduring isolation of pipelines

Partner solutionPartner solution Inspect and repair pipeline valves in Inspect and repair pipeline valves in

vicinity of ongoing pipeline repair/ vicinity of ongoing pipeline repair/ replacement projectsreplacement projects

Methane savingsMethane savings Based on leak rates through gate valves Based on leak rates through gate valves

~ 130 Mcf/yr and gate valve stem ~ 130 Mcf/yr and gate valve stem packing ~ 120 Mcf/yrpacking ~ 120 Mcf/yr

ApplicabilityApplicability All pipeline repair and replacement All pipeline repair and replacement

projectsprojects





NoneNone


$100 - $100 - $1,000$1,000

PaybackPayback 1 - 3 yrs1 - 3 yrs


Inspect & Repair Compressor Station Inspect & Repair Compressor Station Blowdown ValvesBlowdown Valves

What is the problem?What is the problem? Pressure, thermal and mechanical Pressure, thermal and mechanical

stresses wear blowdown valves making stresses wear blowdown valves making them significant emission sources them significant emission sources through inaccessible vent stacksthrough inaccessible vent stacks

Partner solutionPartner solution Annually inspect and repair leaking Annually inspect and repair leaking

blowdown valves at compressor stationsblowdown valves at compressor stations

Methane savingsMethane savings Based on EPAs emission factor for Based on EPAs emission factor for

transmission compressor station transmission compressor station blowdown valvesblowdown valves

ApplicabilityApplicability Applicable to all sitesApplicable to all sites





NoneNone


$100 - $100 - $1,000$1,000



Technology Enabled PROsTechnology Enabled PROs

Install pressurized storage of condensateInstall pressurized storage of condensate

Use of composite wrap repairUse of composite wrap repair

Use ultrasound to identify leaksUse ultrasound to identify leaks

Install flaresInstall flares

Use YALEUse YALE®® closures for emergency shut down (ESD) closures for emergency shut down (ESD) testingtesting

Convert gas-driven chemical pumps to instrument airConvert gas-driven chemical pumps to instrument air


Install Pressurized Storage of Install Pressurized Storage of CondensateCondensate

What is the problem?What is the problem? Condensate from compressor scrubbers, Condensate from compressor scrubbers,

when transferred to atmospheric tanks, when transferred to atmospheric tanks, flash methane to the atmosphereflash methane to the atmosphere

Partner solutionPartner solution Pressurized storage and transport of Pressurized storage and transport of

condensate recovers methane and NGLscondensate recovers methane and NGLs

Methane savingsMethane savings Based on estimate of condensate Based on estimate of condensate

production of 0.01 barrel per Mscf of gas production of 0.01 barrel per Mscf of gas and methane emissions of 0.25 Mcf/ and methane emissions of 0.25 Mcf/ barrelbarrel

ApplicabilityApplicability Compressor stations receiving field Compressor stations receiving field

production gasproduction gas





> $10,000> $10,000


> $1,000> $1,000

PaybackPayback 1 to 3 yrs1 to 3 yrs


Use Ultrasound to Identify LeaksUse Ultrasound to Identify Leaks

What is the problem?What is the problem? Leakage through blowdown, vents Leakage through blowdown, vents

and PRVs cannot be easily detected and PRVs cannot be easily detected when discharged through roof ventswhen discharged through roof vents

Partner solutionPartner solution Use Ultrasonic leak detectors which Use Ultrasonic leak detectors which

can detect leaks inside a valvecan detect leaks inside a valve Methane savingsMethane savings

Assumption that 100 leaks can be Assumption that 100 leaks can be found through the operation’s with found through the operation’s with an emission rate of 20 Mcf/yr/valvean emission rate of 20 Mcf/yr/valve

ApplicabilityApplicability All in-service shut-off valves with All in-service shut-off valves with

open ended dischargeopen ended discharge





< $1,000< $1,000


> $1,000> $1,000

PaybackPayback 1 to 3 1 to 3 yrsyrs


Use YALEUse YALE®® Closures for ESD Testing Closures for ESD Testing

What is the problem?What is the problem? Gas from dump valves during ESD Gas from dump valves during ESD

testing is vented to the atmospheretesting is vented to the atmosphere Partner solutionPartner solution

Use YALEUse YALE®® closures to block dump closures to block dump valves for testing individual valve valves for testing individual valve with minimal gas ventingwith minimal gas venting

Methane savingsMethane savings Based on retrofitting ten 8 inch ESD Based on retrofitting ten 8 inch ESD

valves with a 3 foot stack and relief valves with a 3 foot stack and relief rate of 400 Mcf/minute on a 500 psig rate of 400 Mcf/minute on a 500 psig systemsystem

ApplicabilityApplicability All ESD valvesAll ESD valves





$1,000- $1,000- $10,000$10,000


$100 - $100 - $1,000$1,000

PaybackPayback 1 to 3 1 to 3 yrsyrs


Directed Inspection and Maintenance Directed Inspection and Maintenance at Compressor Stationsat Compressor Stations

What is the problem?What is the problem? Gas leaks are Gas leaks are invisibleinvisible, , unregulatedunregulated and and go unnoticedgo unnoticed

STAR Partners find that valves, connectors, STAR Partners find that valves, connectors, compressor seals and open-ended lines (OELs) are compressor seals and open-ended lines (OELs) are major sourcesmajor sources 27 Bcf methane emitted per year by reciprocating 27 Bcf methane emitted per year by reciprocating

compressors seals and OELscompressors seals and OELs Open ended lines contribute half these emissionsOpen ended lines contribute half these emissions

Facility fugitive methane emissions depend on Facility fugitive methane emissions depend on operating practices, equipment age and maintenanceoperating practices, equipment age and maintenance


Combustion Equipment9.9%

Amine Vents0.5%

Flare Systems24.4%

Non-leaking Components0.1%

NRU Vents0.3%

Storage Tanks11.8%

Leaking Components53.1%

Clearstone Engineering, 2002

Natural Gas Losses by SourceNatural Gas Losses by Source


Control Valves4.0%

Open-Ended Lines11.1%

Other Flow Meters0.2%

Orifice Meters0.1%

Pressure Relief Valves3.5%

Valves26.0%

Blowdowns0.8%

Connectors24.4%

Compressor Seals23.4%

Crankcase Vents4.2%

Pump Seals1.9%

Pressure Regulators0.4%

Clearstone Engineering, 2002

Natural Gas Losses Natural Gas Losses by Equipment Typeby Equipment Type


Methane Leaks by Equipment TypeMethane Leaks by Equipment Type

Component Type% of Total Methane

Emissions% Leakers

Estimated Average Methane Emissions per

Leaking Component (Mcf/Yr)

Valves (Block & Control) 26.0% 7.4% 66Connectors 24.4% 1.2% 80Compressor Seals 23.4% 8.1% 372Open-Ended Lines 11.1% 10.0% 186Pressure Relief Valves 3.5% 2.9% 844

Methane Emissions from Leaking Components at Gas Plants

Clearstone Engineering, 2002, Identification and Evaluation of Opportunities to Reduce Methane Losses at Four Gas Processing Plants. Report of results from field study of 4 gas processing plants in WY and TX to evaluate opportunities to economically reduce methane emissions.


How Much Methane is Emitted?How Much Methane is Emitted?

Summary of Natural Gas Losses from the Top Ten Leakers1

Plant No. Gas Losses From Top 10

Leakers (Mcf/d)

Gas Losses From All Equipment

Leakers (Mcf/d)

Contribution By Top 10 Leakers

(%)

Percent of Plant

Components that Leak

1 43.8 122.5 35.7 1.78

2 133.4 206.5 64.6 2.32 3 224.1 352.5 63.6 1.66

4 76.5 211.3 36.2 1.75 Combined 477.8 892.84 53.5 1.85

1Excluding leakage into flare system


How Can These Losses Be Reduced?How Can These Losses Be Reduced?

Implementing a Directed Inspection and Implementing a Directed Inspection and Maintenance (DI&M) ProgramMaintenance (DI&M) Program

Clearstone Engineering


What is a DI&M Program?What is a DI&M Program?

VoluntaryVoluntary program to identify and fix leaks program to identify and fix leaks that are cost-effective to repairthat are cost-effective to repair

Outside of mandatory LDAR Outside of mandatory LDAR

Survey cost will pay out in the first yearSurvey cost will pay out in the first year

Provides valuable data on leakersProvides valuable data on leakers


How Do You Implement a DI&MHow Do You Implement a DI&M Program? Program?

SCREEN and MEASURE leaksSCREEN and MEASURE leaks

ESTIMATE repair cost, FIX to a Payback criteriaESTIMATE repair cost, FIX to a Payback criteria

PLAN for future DI&MPLAN for future DI&M

RECORD savings/report to Gas STARRECORD savings/report to Gas STAR

CONDUCT baseline surveyCONDUCT baseline survey

FIX on the spot leaksFIX on the spot leaks


Summary of Screening and Measurement Techniques Instrument/ Technique

Effectiveness Approximate Capital Cost

Soap Solution * * $

Electronic Gas Detectors * $$

Acoustic Detection/ Ultrasound Detection

* * $$$

TVA (FID) * $$$

Bagging * $$$

High Volume Sampler * * * $$$

Rotameter * * $$

Screening and MeasurementScreening and Measurement

EPA’s Lessons Learned Study


Cost-Effective RepairsCost-Effective Repairs

Repair the Cost Effective Components

Component Value of

Lost Gas1 ($)

Estimated Repair Cost

($)

Payback (Months)

Plug Valve: Valve Body 12,641 200 0.2

Union: Fuel Gas Line 12,155 100 0.1

Threaded Connection 10,446 10 0.0

Distance Piece: Rod Packing 7,649 2,000 3.1

Open-Ended Line 6.959 60 0.1

Compressor Seals 5,783 2,000 4.2

Gate Valve 4,729 60 0.2

Hydrocarbon Processing, May 2002 1Based on $3/Mcf gas price


How Much Gas Can Be Saved?How Much Gas Can Be Saved?

Natural Gas STAR Lessons Learned study for DI&M Natural Gas STAR Lessons Learned study for DI&M at compressor stations estimatesat compressor stations estimates Potential Average Gas Savings ~ 29,000 Potential Average Gas Savings ~ 29,000

Mcf/yr/compressor stationMcf/yr/compressor station

Value of gas saved ~ $87,000 / compressor stationValue of gas saved ~ $87,000 / compressor station

Average initial implementation cost ~ $26,000 / Average initial implementation cost ~ $26,000 / compressor stationcompressor station


DI&M by Leak ImagingDI&M by Leak Imaging

Real-time visual image of gas leaksReal-time visual image of gas leaks Quicker identification & repair of leaksQuicker identification & repair of leaks Screen hundreds of components an hourScreen hundreds of components an hour Screen inaccessible areas simply by viewing themScreen inaccessible areas simply by viewing them


Infrared Gas Imaging TechnologyInfrared Gas Imaging Technology

Shoulder- and/or tripod- mountedShoulder- and/or tripod- mounted

Hand-held prototypeHand-held prototype

Aerial surveillance applicationsAerial surveillance applications

Require battery and/or power cordRequire battery and/or power cord

Most very large leaks (> 3cf/hr) clearly seenMost very large leaks (> 3cf/hr) clearly seen


Infrared Gas ImagingInfrared Gas Imaging

Video recording of fugitive leak found by Video recording of fugitive leak found by infrared camerainfrared camera


Discussion QuestionsDiscussion Questions

To what extent are you implementing these To what extent are you implementing these opportunities?opportunities?

Can you suggest other opportunities?Can you suggest other opportunities?

How could these opportunities be improved upon or How could these opportunities be improved upon or altered for use in your operation?altered for use in your operation?

What are the barriers (technological, economic, lack What are the barriers (technological, economic, lack of information, regulatory, focus, manpower, etc.) of information, regulatory, focus, manpower, etc.) that are preventing you from implementing these that are preventing you from implementing these practices?practices?

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