The US EIA has said that crude oil inventory data for the week ending February 20 shows that total utilisation of crude oil storage capacity in the US stands at 60%, compared with 48% for the same time in 2014. Most US crude oil stocks are held in the Midwest and Gulf Coast, where storage tanks were between 69% and 56% of capacity as of February 20. The capacity use calculation reflects only crude oil stored in tanks or underground caverns at tank farms and refineries, and excludes some crude oil that is included in commercial inventory data, such as pipeline fill and lease stocks held in production areas.
The EIA has reported that capacity stands at 67% for Cushing, Oklahoma, compared with 50% at the same point in 2014. Working capacity in Cushing alone is reported to be approximately 71 million bbls, or move than half of all Midwest working capacity and approximately 14% of the national total.
Measures of capacity
Net available shell capacity includes tank bottoms, working storage capacity, and contingency space. Tank bottoms are volumes below the normal suction lines of a storage tank that may include water and sediment and are difficult to access. Contingency space is space above the maximum operating inventory level that remains empty during normal operations. This contingency space allows flexibility to exceed working storage capacity without creating safety hazards or operational disruptions.
Working storage capacity excludes contingency and tank bottoms, but is perhaps a more useful measure of capacity. From September 2013 – September 2014, total crude oil working storage capacity increased from 502 million bbls to 521 million bbls. Operation of crude oil storage and transportation systems requires some amount of working storage to be available to be filled at all times in order to receive deliveries by pipeline, tanker, barge and rail. Therefore, it is not possible to completely fill all the working storage capacity that EIA reports on for the US and PADD regions. The exact amount of storage capacity that must be available to maintain operation of crude oil storage and transportation systems is unknown.
Edited from press release by Claira Lloyd
Read the article online at: https://www.hydrocarbonengineering.com/refining/10032015/us-crude-oil-storage-utilisation/