Indiana refinery outage escalates fears Cushing will top out

Concerns among oil traders are escalating that a combination of surprisingly resilient U.S. shale production and lower autumn refinery demand will cause storage tanks in Cushing, Oklahoma, to fill to the brim with surplus crude as early as October. 

http://www.reuters.com/article/2015/08/13/us-oil-spreads-cushing-idUSKCN0QI0ER20150813