## Lessons Learned from the Natural Gas STAR Program 

# Options for Reducing Methane Emissions from Pneumatic Devices

Producers Technology Transfer Workshop
Newfield Exploration Company, Anadarko Petroleum Corporation, Utah Petroleum Association, Interstate Oil & Gas Compact Commission, Independent Petroleum Association of Mountain States


## Vernal, UT March 23, 2010 epa.gov/gasstar



# Pneumatic Devices: Agenda Methane Losses Methane Recovery Is Recovery Profitable? Industry Experience Discussion Questions

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# 2007 Production Sector Methane Emissions Storage Tank Venting Well Venting and Flaring 5 Bcf 7 Bcf Pneumatic Devices Meters and 43 Bcf Pipeline Leaks 8 Bcf
Compressor Fugitives, Venting, And Exhaust 12 Bcf

EPA. Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990 – 2007. April, 2009. Available on the web at: epa.gov/climatechange/emissions/usinventoryreport.html 2 Note: Natural Gas STAR reductions from gathering and boosting operations are reflected in the production sector. 

### Offshore Operations 29 Bcf

Other Sources 7 Bcf

Dehydrators and Pumps 12 Bcf



# What is the Problem? Pneumatic devices are collectively a major source of methane emissions from the natural gas industry Natural gas powered pneumatic devices used throughout the oil and natural gas industry Natural Gas Systems Petroleum Systems Production and Gathering 1 

## 411,000 379,436 Processing 1 

## 11,000
- Transmission and Storage 1 

## 85,000
- 1 - Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990 - 2008 3



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# Methane Emissions As part of normal operations, pneumatic devices release natural gas to atmosphere High-bleed devices bleed in excess of 6 scf/hour Equates to >50 Mcf/year Typical high-bleed pneumatic devices bleed an average of 140 Mcf/year 

# Actual bleed rate is largely dependent on device’s design

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# Location of Pneumatic Devices at Production Sites

Wellheads
SOV = Shut-off valve (Unit isolation) LC = Level control (Separator , contactor, flash tank separator, TEG regenerator) TC = Temperature control (Regenerator fuel gas) FC = Flow control (TEG circulation, compressor bypass) PC = Pressure control (FTS pressure, compressor suction/discharge) PC PC SOV SOV

LC SOV Separator Dehydrator Unit Compressor To Pipeline

FC LC TC FC PC



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# Pneumatic Device Schematic

Pneumatic Controller Process Measurement Liquid Level

Pressure Temperature Flow Weak Signal Bleed (Continuous) Strong Signal Vent (Intermittent)

Process Flow Control Valve Valve Actuator Strong Pneumatic Signal Weak Pneumatic Signal (3 to 15 psi) Regulator Gas 100+ psi Regulated Gas Supply 20 psi

psi = pounds per square inch



# How Can Methane Emissions be Recovered? Option 1: Replace high-bleed devices with low-bleed devices Option 2: Retrofit controller with bleed reduction kits Field experience shows that up to 80% of all high-bleed devices can be replaced or retrofitted wit h low-bleed equipment 

# Option 3: Maintenance aimed at reducing losses

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# Option 1: Replace High-Bleed Devices Most applicable to Controllers: liquid-level and pressure Positioners and transducers 

# Suggested action: evaluate replacements Replace at end of device’s economic life Early replacement

Norriseal Fisher Pneumatic Liquid Electro-Pneumatic Level Controller Transducer

Source: www.emersonprocess.com Source: www.norriseal.com 8



# Option 1: Cost to Replace High-Bleed Devices Costs vary with size: Typical costs range from $700 to $3,000 per device
Incremental costs of low-bl eed devices are modest ($150 to $250) Gas savings often pay for r eplacement costs in short periods of time (2 to 8 months)

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# Option 2: Retrofit with Bleed Reduction Kits Applicable to most high-bleed controllers Suggested action: evaluate cost-effectiveness as alternative to early replacement Retrofit kit costs ~ $675 Payback time ~ 9 months

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# Option 3: Maintenance to Reduce Losses Applies to all pneumatic devices Suggested action: add to routine maintenance procedures Field survey of controllers Where process allows, tune c ontrollers to minimize bleed

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# Option 3: Maintenance to Reduce Losses (cont’d)

Becker Single-Acting 

# Suggested action (cont’d): Re-evaluate the need for pneumatic Valve Positioner 

# positioners Repair/replace airset regulators Reduce regulated gas supply pressure to minimum Routine maintenance should include repairing/replacin g leaking components

Source: www.bpe950.com 

# Costs are low

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# Five Steps for Reducing Methane Emissions from Pneumatic Devices
Locate and INVENTORY high-bleed devices

ESTIMATE the savings
EVALUATE economics of alternatives

DEVELOP an implementation plan ESTABLISH the technical feasibility and costs of alternatives



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# Suggested Analysis for Replacement Replacing high-bleed controllers at end of their economic life End of economic life when major overhaul cost avoidedDetermine incremental cost of low-bleed device over highbleed equivalent Determine gas saved with low-bleed device using manufacturer specifications Compare savings and cost 

# Early replacement of high-bleed controllers Compare gas savings of low-bl eed device with full cost of replacement

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# Economics of Replacement
Replace at End of Life 

## Early Replacement Level Control Pressure Control Cost ($) 1 

### 210 – 340 2 

### 513 1809 Annual Gas Saving (Mcf) 50 - 200 166 228 Annual Value of Gas Saved ($) 3 

### 350 - 1400 1165 1596 Paybacks (months) 3 - 8 6 14 IRR (%) 4 

### 138 - 933 226 84
1 - All data based on partners’ experiences. See Lessons Learned for more information 2 - Range of incremental costs of low-bleed over high bleed equipment 3 - Gas price is assumed to be $7/Mcf 4 - Internal Rate of return IRR calculated over 5 years 15



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# Suggested Analysis for Retrofit Retrofit of low-bleed kit Compare savings of low-bleed device with cost of conversion kit Retrofitting reduces emissions by average of 90% Level Controllers Pressure Controllers Mizer Large to small orifice Large to small nozzle Large to small orifice Implementation Costs 1 ($) 675 41 189 41 Bleed rate reduction (Mcf/device/year) 219 184 131 184 Value of gas saved ($/year) 2 1533 1288 917 1288 Payback (months) 6 <1 3 <1 IRR (%) 3 226 >3100 >450 >3100 1 - All data based on partners’ experiences. See Lessons Learned for more information 2 - Gas price is assumed to be $7/Mcf 3 - Internal Rate of return IRR calculated over 5 years 16



# Suggested Analysis for Maintenance For maintenance aimed at reducing gas losses Measure gas loss before and after procedure Compare savings with labor (and parts) required for activity Reduce Supply Pressure Repair & Retune Change Settings Remove Valve Positioners Implementation Cost ($) 1 207 31 0 0 Gas Savings (Mcf/year) 175 44 88 158 Value of gas saved ($/year) 2 1225 308 616 1106 Payback (months) 3 2 immediate Immediate IRR 3 >500% >900
-- - -- - 1 - All data based on partners’ experiences. See Lessons Learned for more information 2 - Gas price is assumed to be $7/Mcf 3 – Internal rate of return (IRR) calculated over 5 years 17



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# Industry Experience – Chesapeake Energy Level controllers retrofitted with Mizer components
Hi-flow sampler used to measure Fisher 2500, 2506 Retrofit w/ Mizer, bracket, 

# emissions reduction from tubing & relay plug 

# retrofits

Invalco 415, 215, 402 Cemco/WellMark 6900 Retrofit w/ Mizer valve, Retrofit w/ Mizer Valve block & gauges 18



# Industry Experience – Chesapeake Energy

District Retrofits Done Thru 31-Mar-09 Total Capital ($) Daily Reduction (MCF) Annual Reduction (MMCF) Anadarko 1264 685,088 885 324 Arkansas 100 54,200 70 26 N. Mid Continent 467 253,114 327 98 Southern Oklahoma 372 201,264 260 99 W. Mid Continent 47 25,474 33 13 Gulf Coast 161 87,262 113 41 Louisiana 17 9,214 12 4 N. Permian 93 20,406 65 24 S. Permian 149 80,578 104 22 Total 2,670 1,447,140 1869 651 Average Installation Cost = $542 Using $3.50/MCF, the simple payback is 7 months 19



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# Lessons Learned Most high-bleed pneumatics can be replaced with lower bleed models Replacement options save the most gas and are often economicRetrofit kits are available and can be highly costeffective Maintenance is low-cost and reduces gas loss

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# Discussion Questions To what extent are these opportunities being implemented? How could these opportunities be improved upon or altered for use in your operation? What are the barriers (technological, economic, lack of information, regulatory, focus, manpower, etc.) that are preventing you from implementing these practices?

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