[akg_67]

If you think Cushing storage of 3 days is massive, you will be shocked with Strategic Petroleum Reserve maintained by US govt, that covers a large swath underground below Texas and Louisiana states, and only holds about 30 days of consumption.

https://en.wikipedia.org/wiki/Strategic_Petroleum_Reserve_%2...

Actually, Cushing storage is not that much. Unlike SPR, it is mostly short term storage in between transit. Cushing is a transfer point between different pipelines that connect at Cushing which also later became a delivery point for oil and gas futures traded in futures market.

[Someone]

The norm for a country's total reserves is 90 days of imports (https://en.m.wikipedia.org/wiki/Global_strategic_petroleum_r...)

US imports are about 1/4 of consumption (http://www.eia.gov/tools/faqs/faq.cfm?id=32&t=6), so total reserves (including commercial storage) should be around 25 days.

As to Cushing, from both the article and what you say I would be more concerned about losing those pipes than of losing the oil stored there.