"All personnel have been accounted for, and there were no injuries or off-site impacts associated with this incident," a company spokeswoman said in an email.
The cause was under investigation, the company said.
The company did not provide details about the operational status of the units involved or information on supply.
The Deer Park facility houses a 327,000 barrel-per-day (bpd) refinery and a chemical plant and is a 50-50 joint venture between Shell (LSE: RDSB.L - news) and Mexican national oil company Pemex. (Reporting by NR Sethuraman in Bangalore)