They borrowed $1.55bln for two days according to their 8-K.
Here's a link to WSJ blog post: http://blogs.wsj.com/moneybeat/2016/04/04/why-an-energy-company-borrowed-1-55-billion-for-two-days/?mod=yahoo_hs
I must admit I am surprised that SWN has the expertise to know they can do this to increase their borrowing capacity. Who would have thought they would actually read the agreements?