Will Seaway pipeline reversal reduce Cushing stocks?

Crude oil stocks in Cushing Oklahoma as of 27th April reached to the historical record at 42.96 million barrels, according to the latest data by the U.S. Energy Information Administration.

Previous record was 41.9 million barrels posted in April 2011. Cushing inventories had decreased during May 2011 and January 2012 toward just above 28 million barrels level. The crude oil stocks have surged to the new record level over the past few months.

Cushing is a centre of petroleum refineries and crude oil transportation in the U.S. Midwest. Since physical delivery of NYMEX WTI futures contracts is done in the region, its inventory level is watched by market participants.

Crude oil produced in the U.S. southern region and imports arrived in Mexican Gulf coast are supplied to the Midwest area.

Moreover, Keystone pipeline has started delivering crude oil from Canada and North Dakota to Midwest since February last year. The fresh supply has been recognized as high inventory pressure in the Midwest region.

Crude oil imports into the Midwest region has certainly increased after mid-2011. But Cushing inventories were declining consistently during the later half of 2011 despite the increasing supply.
Also, growth of crude oil imports into the Midwest region remains in the same pace as previous, despite surged Cushing inventories in this year.

We can not see definite correlation between the supply and inventory...

Trends for crude oil imports in the U.S. each region also do not show apparent change. Imports into the Mexican gulf coast dipped in July last year from previous  5-6 million barrels per day to 4-5 million bpd and still have maintained that level.

Some people explain that recent higher Cushing inventories are preparing for the Seaway pipeline reversal scheduled to start operation in late May.

The pipeline was used to transport crude oil from Mexican gulf to Midwest, but the reversal operation is expected to reduce the inventory pressure in the Midwest area where has had no route to release crude oil.

The Seaway pipeline is scheduled to transport 150,000 bpd of crude oil in the beginning. The transportation volume is likely to increase to about 400,000 bpd by the 1Q 2013.

However, I am not sure whether the Seaway pipeline reversal will reduce Cushing inventories or not, because increased imports caused by the Keystone pipeline have not had certain correlation against the inventory level.