Aerodyne Research, Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States.
Environ Sci Technol. 2020 Mar 17;54(6):3530-3538. doi: 10.1021/acs.est.9b07148. Epub 2020 Mar 9.
Shipboard measurements of offshore oil and gas facilities were conducted in the Gulf of Mexico in February 2018. Species measured at 1 s include methane, ethane, carbon-13 (C) and deuterium (D) isotopes of methane, and several combustion tracers. Significant variability in the emission composition is observed between individual sites, with typical ethane/methane ratios around 5.3% and C and D methane isotopic compositions around -40 and -240‰, respectively. Offshore plumes were spatially narrower than expectations of the plume width based on terrestrial atmospheric stability classes; a modified Gaussian dispersion methodology using empirically measured horizontal plume widths was used to estimate the emission rates. A total of 103 sites were studied, including shallow and deepwater offshore platforms and drillships. Methane emission rates range from 0 to 190 kg/h with 95% confidence limits estimated at a factor of 10. The observed distribution is skewed with the top two emitters accounting for 20% of the total methane emissions of all sampled sites. Despite the greater throughput of the deepwater facilities, they had moderate emission rates compared to shallow-water sites. Analysis of background ethane enhancements also suggests a source region in shallow waters. A complete 1 s measurement database is published for use in future studies of offshore dispersion.
2018 年 2 月，在墨西哥湾对海上石油和天然气设施进行了船舶测量。在 1 秒时间内测量的物种包括甲烷、乙烷、碳-13（C）和氘（D）同位素甲烷，以及几种燃烧示踪剂。各个站点之间的排放成分存在显著的可变性，典型的乙烷/甲烷比约为 5.3%，C 和 D 甲烷同位素组成分别约为-40 和-240‰。海上羽流的空间宽度比基于陆地大气稳定度类别的羽流宽度预期要窄；使用经验测量的水平羽流宽度的修正高斯扩散方法来估计排放率。共研究了 103 个站点，包括浅水区和深水区海上平台和钻井船。甲烷排放率范围为 0 至 190 kg/h，95%置信限估计为 10 的因子。观察到的分布呈偏态，前两个排放源占所有采样点总甲烷排放量的 20%。尽管深水区设施的吞吐量更大，但与浅水区站点相比，它们的排放率适中。背景乙烷增强的分析也表明浅水区存在一个源区。发布了一个完整的 1 秒测量数据库，供未来海上扩散研究使用。
