A slump in base oils and lube production in the Louisiana region of the US Gulf coast in January accounted for most of the drop in total US output that month.

Production in the Louisiana Gulf coast region fell to 1.04mn bl in January, down 36pc from 1.62mn bl the previous month, according to the EIA. Output in the region averaged around 1.62mn bl/month in 2021.

The January volume was the lowest since output fell to 822,000bl in February 2020, just before lockdowns caused by the Covid-19 pandemic.

It was also lower than output of 1.08mn bl in September 2020, when extensive storm damage affected refinery production in the Louisiana region.

Paraffinic base oils production also fell in the US East coast region in January from the previous month. But its 4pc fall in output lagged the 16pc fall in total US paraffinic base oils output that month.

The Louisiana Gulf coast region is home to several refineries with base oils production. These include Phillips 66’s 264,000 b/d Westlake refinery, ExxonMobil’s 520,000 b/d Baton Rouge refinery, and Chevron’s 356,000 b/d Pascagoula refinery.

Base oils output tends to fluctuate every month. A sharp change in production typically takes place because of planned or unexpected issues such as maintenance work.