NEW ORLEANS – Operators of offshore supply vessels say they are bracing for a shortage of qualified crew members that could drive up costs and hamper the pace of deepwater drilling in the Gulf of Mexico more than two years after the BP oil spill.

Covington-based Hornbeck Offshore Services reported earlier this month that its operating expenses for the year could rise to $255 million, up $13 million from earlier forecasts, blaming higher labor costs. The company says competition for offshore mariners is increasing and driving up the wages that are paid.

Hornbeck warned in its most recent quarterly filing with the Securities and Exchange Commission that the shortage — spurred in part by new regulatory requirements and increases in required staffing levels on some vessels — could mean that fewer supply vessels are available to support deepwater drilling operations in the Gulf.

Last summer, some in the industry speculated that as many as 50 vessels had moved from the region in the 15 months after the spill.

Joseph Bennett, chief of investor relations for Tidewater Inc., a New Orleans company that operates a fleet of supply vessels for the oil and gas industry, said that although it operates primarily in international waters, Tidewater is not immune to work force pressures, “especially as more equipment is needed.”

“When you’re a capital-intensive company or an industry like we are, that requires people to run the equipment,” Bennett said.

Shane Guidry, chairman and chief executive of Harvey Gulf International Marine in New Orleans, said that as some operators dry-docked their supply vessels or left the Gulf in the months after the Deepwater Horizon disaster, many qualified local mariners were laid off and may have since abandoned the field or started work on different kinds of vessels.