After a fire on August 22 that knocked out production at its E-Ku-A2 offshore platform, Petroleos Mexicanos (Pemex) is reportedly injecting nitrogen into the oil wells to resume output. According to a report from Bloomberg, the company has been working to restore full production today, and has turned to nitrogen as a solution to push oil out of the wells in the absence of natural gas, also offline due to the fire.

Unlike natural gas, nitrogen can spread oil into pockets within the reservoir, causing long-term issues with exploration.

The fire, which killed at least five people and injured six others, shut down production of 421,000 barrels per day, about 25% of Mexico’s total production.