Partner Reported Opportunities (PROs) PRO Fact Sheet No. 904 for Reducing Methane Emissions 

Install Flares 

Technology/Practice Overview 

Description 

Remote, unmanned production sites and 

compressor stations may vent lowpressure natural gas and vapors from 

storage tanks and other onsite 

equipment to the atmosphere. These 

gases, which contain methane and often

volatile organic compounds (VOC), 

hydrogen sulfide, and hazardous air 

pollutants (HAP), can pose an 

environmental, health, and safety 

hazard. In order to reduce these 

emissions, Partners have reported 

installing flares to combust these gases 

instead of venting them to the 

atmosphere. 

Partners have applied flaring technology 

typically consisting of a small flare stack 

with one or two pilots. Emissions 

sources, such as tank vents, compressor 

blowdown lines, low-pressure separator 

vents, overpressure relief valves, and 

other vent streams are piped directly to

the flare. 

Operating Requirements 

If the heat content of the stream is below 

300 Btu per scf, auxiliary fuel is needed. 

The average pilot gas consumption is 70 

scf per hour per pilot burner. 

Applicability 

Flares can be applied to all point source 

vented emissions of combustible gas with 

minimal sulfur content. 

Methane Emissions 

The methane emissions reduction is 

uniquely dependent on the types and

sizes of sources and the methane content 

of the flared gas. Wellhead gas may

range from 70 to 90 percent methane 

while crude oil production tank vapors 

Compressors/Engines 

Dehydrators 

Directed Inspection & 

Maintenance 

Pipelines 

Pneumatics/Controls 

Tanks 

Valves 

Wells 

Other 

Applicable Sector(s) 

Production 

Processing 

Transmission 

Distribution 

Other Related PROs: 

Install Electronic Flare Ignition 

Devices, PRO No. 903 

Estimated 

Gas Price 

Annual 

Methane 

Savings 

Value of 

Annual

 Gas Savings* 

Estimated 

Implementation 

Cost 

Incremental 

Operating Cost 

Payback 

(months) 

$7.00/Mcf 2,000 Mcf N/A $21,000 $4,200 None 

$5.00/Mcf 2,000 Mcf N/A $21,000 $3,000 None 

$3.00/Mcf 2,000 Mcf N/A $21,000 $1,800 None 

Economic and Environmental Benefits 

Economic Evaluation 

Additional Benefits 

 Safer operations 

Estimated annual methane emission reductions 2,000 Mcf per flare (with a single pilot) 

Methane Savings 

* Because the natural gas is flared, there are no economic gas savings associated with this activity. 
 

 

 

PRO Fact Sheet No. 904 Continued 

Install Flares (Cont’d) 

may be as low as 50 percent methane. Partners have 

reported production site application for tank vents, relief 

valves, and compressor blow-down at 2,000 Mcf per year, 

low-pressure separators at 4,000 Mcf per year, and

condensate tanks at 36,000 Mcf per year. 

Economic Analysis 

Basis for Costs and Emissions Savings 

Methane emissions reductions of 2,000 Mcf per year 

apply to a single flare with a single pilot. Costs for a 

flare are estimated to be $3,000 based on partner

experiences (which vary significantly and are often

between $1,000 and $5,000). In addition, and there is a

fuel cost of $1,800 per year for each pilot (at $3 per Mcf of 

gas). 

Discussion 

Flares are commonly installed on higher-pressure 

blowdown or emergency pressure relief valves for safety 

reasons. Low-pressure gas installations have been 

justified by environmental emissions control. There are 

no revenues from the gas as it is destroyed through 

combustion. 

The average methane content of natural gas varies by natural gas 

industry sector. The Natural Gas STAR Program assumes the 

following methane content of natural gas when estimating 

methane savings for Partner Reported Opportunities. 

Production 79 % 

Processing 87 % 

Transmission and Distribution 94 % 

Methane Content of Natural Gas 

EPA provides the suggested methane emissions estimating methods contained 

in this document as a tool to develop basic methane emissions estimates only. 

As regulatory reporting demands a higher-level of accuracy, the methane emission estimating methods and terminology contained in this document may not 

conform to the Greenhouse Gas Reporting Rule, 40 CFR Part 98, Subpart W 

methods or those in other EPA regulations. 

2011 2