这是从美国出口到加拿大的流量。从加拿大入口的流量是1.792BCF /d。看来这两个数据要相减。

http://www.pennenergy.com/articles/pennenergy/2015/08/pipeline-news-alliance-force-majeure-to-cut-natural-gas-flows-to-zero-for-unspecified-length-of-time.html

During the past 30-days, Alliance Canada has been flowing an average 1,792 MMcf/d across the border to Alliance U.S., with single-day flows reaching as high as 1,977 MMcf/d on the roughly 2,000 MMcf/d capacity