Citgo Petroleum Corp is working on a start-up plan for its 167,500 barrel-per-day (bpd) Corpus Christi, Texas, refinery, which was shut last week due to severe winter weather conditions.

"We are progressing on a thorough assessment of potential damages," Citgo said in an emailed statement on Monday.

The company also said its 418,000 barrel-per-day Lake Charles, Louisiana refinery is now operating at full production.

As per a Texas Commission on Environmental Quality (TCEQ) filing, the company reported refinery utilities (steam, nitrogen, water) were impacted due to a severe weather event and are gradually being restored at Corpus Christi, West and East Plants.

The cold snap knocked out nearly 4 million bpd of the US refinery capacity. As the brutal cold starts to ease, other refiners also started ramping up operations.