Pipeline Blowdowns
Summary
Pipeline blowdowns are routine operations on natural gas transmission and distribution systems to allow operators to safely perform maintenance, inspections, construction, and emergency response. This practice involves isolating and depressurizing a section of the pipeline and typically venting the natural gas to the atmosphere, which can result in methane emissions, loss of product and sales, customer inconvenience (including noise levels), and costs associated with evacuating the pipeline section.
Description
Natural gas transmission systems transfer gas from production and gas processing areas to local distribution companies who then deliver gas to customers via distribution lines. On occasion, natural gas transmission and distribution companies may need to shut down and depressurize a segment of pipeline for maintenance, inspections, emergency response, and other situations. It is common practice to shut down a portion of the system during these operations, vent the gas within the isolated segment, and purge the pipeline with inert gas (i.e., nitrogen and carbon dioxide) to preclude fire or explosion hazards. The volume of emissions released during these activities depends upon several factors, including operating temperature and pressure. The volume of gas vented in high pressure transmission pipelines may be 40 to 60 times the actual volume of the isolated segment. Unless mitigation measures are implemented, natural gas is released to the atmosphere via vents or stacks.
References
Interstate Natural Gas Association of America. (2018, August). Improving methane emissions from natural gas transmission and storage. https://www.ingaa.org/File.aspx?id=34990&v=56603504
Lowell, D., Jones, B., Seamonds, D., & Russell, P. (2016, June). Analysis of Pipeline and Hazardous Materials Safety Administration proposed new safety rules: Pipeline blowdown emissions and mitigation options. Environmental Defense Fund Blog: Energy Exchange. https://blogs.edf.org/energyexchange/files/2016/07/PHMSA-Blowdown-Analysis-FINAL.pdf (1 MB)
Tangeman, J. (2017). Mitigating emissions from pipeline blowdowns. Kinder Morgan. https://www.epa.gov/sites/default/files/2017-11/documents/12.tangeman_2017aiw.pdf (881 KB)
U.S. Environmental Protection Agency. (2009, January 29). Greenhouse gas emissions reporting from the petroleum and natural gas industry – Background technical support document. https://www.epa.gov/sites/default/files/2015-05/documents/background-tsd-posted-4-12-10-epa-hq-oar-2009-0923-0027.pdf (1 MB)
Please Note: This platform reflects experiences and lessons learned from voluntary program partners. Some of these emission sources and technologies are now regulated at the federal, state, and/or local level in the United States and in other countries. The end user is solely responsible for complying with any and all applicable federal, state, and local requirements. For information on U.S. regulations for the oil and gas industry, refer to eCFR. EPA makes no expressed or implied warranties as to the performance of any technology and does not certify that a technology will always operate as advertised. Mention of names of specific companies or commercial products and services does not imply endorsement.