Quantification of emissions due to the natural gas storage well-casing blowout at Aliso Canyon/SS-25 using tracer flux ratio methods.
Abstract
The methane emission rate from the well blowout at Aliso Canyon Natural Gas Storage Facility in Porter Ranch, California was quantified using the tracer flux ratio method (TFR). Over 400 tracer plume transects were collected, each lasting 15-300 seconds, using instrumentation aboard a mobile platform on 25 days between December 21, 2015 and March 9, 2016. The leak rate from October 23rd to February 11th has been estimated here using a combination of our leak rate measurements (TFR) and the flight mass balance (FMB) data [Conley et al., 2016]. The TFR approach employed here is assessing only the leaks due to the SS-25 well blowout and excludes other possible emissions at the facility. By "calibrating" the FMB dataset, the leak rate is integrated from Oct 23rd to December 21th. The sum of the inferred inferred and measured meissions suggests a total leak burden of 86,022 ± 8,393 metric tons of CH4. The primary uncertainty in this value is due to the uncertainty in the emission rate prior to the beginning of the TFR quantification. The ethane to methane enhancement ratio observed downwind of the leak site is consistent with the content of ethane in the natural gas at this site and provides definitive evidence that the methane emission rate quantified via tracer flux ratio is not due to a nearby landfill or other potential biogenic sources.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A14E..02H
- Keywords:
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- 0345 Pollution: urban and regional;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0394 Instruments and techniques;
- ATMOSPHERIC COMPOSITION AND STRUCTURE