### EPA Office of Air and Radiation

epa.gov/gasstar 

# Overview of Reduced Emissions Completions (RECs)

Cost

- effective practice to recover natural gas and condensate produced during flowback following hydraulic fracture of natural gas wells.

# U.S. Oil & Natural Gas System Emissions

2 Oil and Gas Production, 397 Bcf 64%

Transmission and Storage, 110 Bcf 18% Distribution, 72 Bcf 11% Processing,

44 Bcf 7% Oil Downstream,

2 Bcf <1% Bcf = billion cubic feet

EPA. Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990

– 2009. April, 2011. Available on the web at: epa.gov/climatechange/emissions/usinventoryreport.html. 2009 U.S. Oil and Gas Industry Methane Emissions (624 Bcf / 252 million tonnes CO2E)

# 2009 Oil and Natural Gas Production Emissions Sources

3 2009 Production Sector Methane Emissions (397 Bcf / 160 million tonnes CO 2 e)

Source: EPA. Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990

– 2009. April, 2011. Available on the web at: epa.gov/climatechange/emissions/usinventoryreport.html. Bcf = billion cubic feet

Storage Tank Venting 14 Bcf Other Sources

13 Bcf Pneumatic Devices

67 Bcf

Well Venting and Flaring 217 Bcf Offshore Operations 37 Bcf Dehydrators and Pumps 19 Bcf

Meters and Pipeline Leaks 12 Bcf Compressor Fugitives,

Venting, and Engine Exhaust 18 Bcf

# Overview of Hydraulic Fracturing
Gas wells in tight formations, coal beds, and shale may require hydraulic fracture to produce gas For new wells or re

-fracturing to stimulate production of existing wells (workovers) 

### During completion of the well, flowback of fracturing liquids 

### and proppant (often sand) is necessary to clean out the well bore and formation prior to production High volume of liquid and solids are produced at high pressure to expel sand, cuttings, and hydraulic fracture fluids prior to production 

### Hydraulic fracturing video: www.northernoil.com/drilling.php Video is for oil production but well drilling and hydraulic fracture process similar for gas

4

# Natural Gas Losses during Gas Well Completions and Workovers One standard practice is for operators to produce flowback to an open pit or tank to collect sand, cuttings, and fluids for disposal Vent or flare the natural gas 

## Typical composition of pollutants in flowback emissions: Primarily methane (CH 4

### ) Substantial amount of VOCs Trace amounts of HAPs

5 Source: Newfield

# Reduced Emission Completions (RECs) Practice to recover natural gas and condensate produced during flowback following hydraulic fracture 

### Portable equipment brought to well site Separates sand and water Processes gas and condensate for sales 

### Route recovered gas through dehydrator and meter to sales line, reducing venting and flaring while increasing gas sales

Portable REC Equipment Source: Weatherford 6

# RECs: Equipment Skid or trailer mounted portable equipment to capture 

## produced gas during cleanup Sand trap 

### Three

-phase separator 

## Use portable dehydrator to remove water 

## from the produced gas before it enter sales line

Source: Williams 7

# RECs: Diagram

8 Temporary, Mobile Surface Facilities, Adapted from BP (for produced fluid, mainly water)

# RECs: Preconditions Permanent equipment required on site before cleanup Nearby gathering system / sales line Piping from wellhead to sales line 

### Lease meter Gas quality meets gathering system specification Stock tanks for wells producing significant amounts of 

### condensate Dehydrator (if needed to process gas to pipeline 

### specifications)

9

# RECs: Benefits Reduced methane and other air emissions during completions and workovers 

### Increase sales revenue from recovered gas and condensate Partners report recovering 500 to 2,000 Mcf/day/well Partners also report recovering zero to several hundred bbl/day/well of condensate (which can result in significant additional revenue) Typical well flowback time is 3 to 10 days 

### Improved relations with government agencies, public, and neighbors 

### Reduced environmental impact Reduced disposal costs

10

# Partner Experience Economics Noble in Ellis County, Oklahoma RECs on 10 wells using energized fracturing 

### Total cost of $325,000 Estimated net profits: $340,000, or $34,000 per well on average 

## BP in Green River Basin, Rocky Mountain region RECs on 106 total wells, high and low pressure Capital investment of ~$500,000 per skid (including portable 

### three

-phase separators, sand traps, and tanks) Conservative net value of gas saved: $20,000 per well 

## A Partner Company (Fort Worth Basin, Texas) RECs on 30 wells Incremental cost of $8,700 per well 

### Conservative net value of gas saved: about $50,000 per well

11

# Related Regulations

Oil and Gas Systems Greenhouse Gas Reporting Rule, Subpart W Reporting of emissions from the oil and gas sector For hydraulically fractured well completions and workovers, will collect total number of completions and workovers and emissions from these sources as well as the number of wells using Reduced Emission Completion techniques and total gas recovered for sales
Clean Air Act (CAA) New Source Performance Standards (NSPS) and National Emissions Standards for Hazardous Air Pollutants (NESHAP) Review EPA is currently reviewing CAA NSPS and NESHAP for the oil and gas sector Proposed rule projected for release July 2011 EPA has identified completion of fractured gas wells to be a significant source of emissions and is considering coverage under the NSPS State Regulations Wyoming requires “ flareless completions” for wells in Jonah

- Pinedale and concentrated development areas Colorado requires sand traps, surge vessels, separators, and tanks as soon as practicable during flowback and cleanout of certain wells EPA is also addressing potential water or other impacts under relevant statutes including Safe Drinking Water Act, Clean Water Act, Resource Conservation and Recovery Act 1213 

# References
Natural Gas STAR Program: http://www.epa.gov/gasstar/

Natural Gas STAR Technical Documents: http://www.epa.gov/gasstar/tools/recommended.html
2011 U.S. Greenhouse Gas Inventory Report: http://epa.gov/climatechange/emissions/usinventoryreport.html