The Good, the Bad and the Ugly – The Strategic Petroleum Reserve
18th April 2022
The U.S. Strategic Petroleum Reserve (SPR) is facing significant challenges related to the storage and availability of its crude oil resources. Approved for construction by the 1975 Energy Policy and Conservation Act (EPCA), the storage sites were envisioned to be needed for 25 years and are subject to an estimated five drawdown cycles (Shages, 2014). In retrospect, the design has not matched actual use, and this has led to degradation of the SPR and impacted its ability to perform its function.
The SPR stores crude oil (either sweet or sour) in 62 underground salt caverns located at four different sites in Texas and Louisiana. The official storage capacity is 727 million barrels, based on sonic measurements. A 2010 study concluded there was a significant mismatch in design and use of the storage caverns. Instead of the initial estimated five large drawdown cycles, a large number of small drawdowns occurred over the previous 20 years. From 1996 through 2014, there were 14 instances of oil removals less than 10 million barrels. These multiple drawdowns have caused cavern deformation, salt falls and other damage to the cavern integrity. In addition, these underground salt caverns are shrinking due to tectonic stresses. The cavern shrinkage (aka closure) is estimated to be approximately two million barrels per year – but may be significantly higher.