The reasons for the dearth of qualified job candidates are varied. Both Mercer and Manpower cited age, disruptive technology like hydraulic fracturing and education as key drivers of the problem.
The latter, however, is the subject of much controversy. Critics of the skills gap argument say it's often used as a cover for companies to ship jobs to low-wage workers overseas. Others argue that if U.S. companies need highly specific skills, they should train people for them.
Manpower's Perez said that most companies are loath to ship jobs offshore, however, because they've simply become more expensive. A hallmark of the U.S. manufacturing renaissance is that the energy boom has helped make labor-intensive sectors cheaper than a decade ago, Perez said.
Read MoreBooming US energy sector may overtake manufacturing
Manpower calls energy companies, government and educational institutions to work together to promote the sector and provide job opportunities.
Perez said he believes a helpful model could be replicated from old-line manufacturers. Automakers, for instance, were known to use in-house "colleges" and specialty institutes to train and advise workers.
"We need to think about how we reposition the 'cool factor' of technical jobs" like oil and gas, Perez said. "The energy sector is a great environment to work. … [They're] not the dirty, bad jobs we sometimes think of."
—By CNBC's Javier E. David