As of March 31, 2012 working crude oil storage capacity at the Cushing, Oklahoma storage and trading hub was 61.9 million barrels, an increase of 6.9 million barrels (13%) from September 30, 2011 and 13.9 million barrels (29%) from a year earlier, as reported in EIA's recently released report on Working and Net Available Shell Storage Capacity.
Utilization of working storage capacity on March 31, 2012 was 64%, an increase from the 53% observed in September 2011, but lower than the 86% observed on March 31, 2011. The report also noted that operating shell storage capacity increased 8.1 million barrels (12%) from September 30, 2011 to reach 74.6 million barrels.
Both storage capacity and the level of inventories held at Cushing are closely watched market indicators, as Cushing is the market hub for West Texas Intermediate (WTI) crude oil that is the basis for crude oil futures contracts traded on the New York Mercantile Exchange. High inventory levels at Cushing have been a symptom of transportation constraints that have resulted in WTI trading at a discount relative to comparable grades of crude oil since early 2011.
Growing volumes of U.S. crude oil production, along with a higher level of imports from Canada, have helped contributed to the record levels of inventories at Cushing. Increased flows of crude oil from these two sources, along with expectations for future increases, have consequently created the need for additional storage at the hub.
Weekly data show that as of June 1, 2012, crude oil inventories held at Cushing were 47.8 million barrels, the highest level on record and very close to total working storage capacity as of March 2011. However, due to the growth in storage capacity between March 2011 and March 2012, the utilization rate for working storage capacity at Cushing has actually declined over the past 14 months.