Page 1 of 5 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF
AIR AND RADIATION

Petroleum and Natural Gas Systems (Subpart W) of the Greenhouse Gas Reporting

Rule Docket: EPA-HQ-OAR-2009-0923

Title: Minimum Gas Pr ocessing Throughput

Summary: The purpose of this analysis is to de termine a clear distinction between gas processing facilities and gas gathering facilities for subpart W of the MRR.Page 2 of 5 Minimum Gas Processing Throughput

The purpose of this analysis is to determin e a clear distinction be tween gas processing facilities and gas gathering facilities for subpart W of the MRR. By removing gas gathering and boosting equipment from today’s fi nal rule, there could be uncertainty as to exactly where the gas processing segment starts in relationship to gas gathering. Today’s final rule applies two criteria for gas pr ocessing segment: fractionation and throughput. All processing plants with fractionation are processing facilities. Those gas processing plants that do not have fr actionation, but have gas thr oughput capacity greater than 25 mmscfd are processing facilities.

Data

In considering this question of what dis tinguishes gas processing from gathering, EPA

consulted the Oil and Gas Journal Worldwide Gas Processing Survey, 1 This survey lists all the U.S. Gas Processing Plants, incl uding their capacity a nd unit processes (e.g. fractionators, acid gas removal, sulfur plant, etc. This survey illustrates the throughput capacity of all processing facilities that ow ner-operators submitted for their processing plant(s). Not all of these plants have fractionation.

EPA then considered the GHG emissions from these processing plants. The subpart W Technical Support Document 2 lists all of the processing plants from the OGJ survey, along with calculated GHG emissions. Th e method of calculating processing plant

emissions is described in the TSD. This da ta was plotted for processing plants without fractionation in Figure 1 and for all processi ng plants in the OGJ survey in Figure 2.

Analysis

Figure 1 plots the 2005 throughputs for gas pr ocessors (processi ng plants without fractionation), in million cubic feet per day, listed in the OGJ 2006 Worldwide Gas Processing Survey against the total emission for each plant determined in the threshold analysis. The 2005 natural gas throughput and emissions are plotted using a logarithmic

scale. The vertical line marks the 25,000 tonne CO 2 e threshold for reporting to the MRR. The horizontal line marks a reporting throughput floor at 25 million cubic feet per day just below the smallest gas processing plan t that will have to report emissions under subpart W. The smallest gas processing pl ant without fractionati on has a throughput of

1.5 mmcfd and is well below the subpart W reporting theshold.

Figure 2 plots the 2005 throughputs for every pro cessing plant, in million cubic feet per day, listed in the OGJ 2006 Worldwide Gas Processing Survey and the total emission for each plant determined in the threshold anal ysis. The 2005 natural gas throughput and the emissions are plotted using a logarithmic s cale. Again, the vertical line marks the 25,000

tonne CO 2 e threshold for reporting to the MRR. The horizontal line at 25 million cubic

1 OGJ. (2006) Worldwide Gas Processing Survey . Oil and Gas Journal < http://www.ogj.com >

2 EPA. (2010) Technical Support Document. Subpart W. Final Mandatory Reporting Rule. Environmental Protection Agency. Appendix C. Docket No. (EPA-HQ-OAR-2009-0923)Page 3 of 5 feet per day from Figure 1 marks the potenti al throughput floor for processing facilities.

It is observed that this throughput floor would exclude mo re than 200 processing plants

that have fractionation from the defin ition of a processing facility, including approximately 40 that are above the 25,000 tC O2e reporting threshold. EPA believes that there are gas gathering and boosting stat ions with throughputs above the minimum throughput of the smallest non- fractionating process plant in the OGJ survey: 1.5 mmcfd.

Conclusion

EPA concluded that fractionation alone w ould not suffice as a definition for gas processing, as there are severa l plants in the OGJ survey with emissions well above the reporting threshold and a few near enough to the threshold that combustion emissions alone may not require them to report to subpart C. Furthermore, excluding some fractionation plants from the OGJ survey doe s not conform with the existing Clean Air Act facility definition; most, if not all of th ese fractionation plants are likely permitted. It is difficult to argue that a ga s processing plant w ith fractionation, represented in the OGJ gas processing survey, is a gathering/boosti ng station. Therefore, today’s final rule defines gas processing facili ties as those with frac tionation and those without fractionation with a gas throughput ca pacity of 25 mmcfd and above.Page 4 of 5Figure 1. Natural Gas Processing Plant Throughputv. Total Emissions for Gas Processors Only1101001000 1 , 000 1

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2005 Natural Gas Processing Plant Throughput (MMcfd)25 Million Cubic Feet per Day25,000metrictonsCO2ePage 5 of 5Figure 2. Processing Plant Throughputv. Processing Facility Emissions0.101.0010.00100.001,000.0010,000.00 1,000 1

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2005 Natural Gas Processing Plant Throughput (MMcfd)25 Million Cubic Feet per Day25,000metrictonsCO2e