A saltwater disposal well reportedly exploded around 4:45 a.m, said the Karnes County Sheriff's Office. The injured person was transported off the scene by Airlife in an unknown condition.
According to one of the workers, the man is believed to be in his early 30s and is from Gonzales county.
Karnes County Sheriff Dwayne Villanueva said the fire had settled down, but that there's still danger of a follow up explosion.
Highway 80 between Gillett and Nixon, and Highway 119 to Yorktown, both of which are close to the explosion site, were shut down after the incident.
The sheriff identified Gulf Coast Acquisitions as the company that owns the well.
Karnes City, Kenedy, Gillett and Nixon fire departments responded to the scene of the explosion.