Mr. Triepke predicted that over the next six months, the big three land drilling companies — Helmerich & Payne, Nabors Industries and Patterson-UTI Energy — are “likely to cut approximately 15,000 jobs out of the 50,000 people they currently employ.”

Already, day rates that oil companies are willing to pay for rigs have dropped 10 percent, Helmerich & Payne said. That is a sign, analysts said, that producers are trying to squeeze costs before they cut revenue-producing output required to pay dividends and the interest on their debts.

Even with the reductions, though, large-scale layoffs across the industry are not expected, at least not immediately. Producers contract their rigs for as long as three to four years, and many companies have hedges that lock in higher prices than the going market rates. In addition, producers often need to drill simply to retain their leases or keep their revenue up.

Nationwide, the oil industry employs about a million people, including extraction, pipeline construction and refining, and the boom has added about 150,000 industry jobs over the last three years, according to Citi Research.

Industry executives say companies are reluctant to let highly skilled workers go, especially when oil prices are likely to rebound in the next couple of years as global energy demand rises. But rig and fracking crews will inevitably be let go first, they said, since those workers can easily be rehired or replaced when drilling rebounds.

Domestic oil production has increased by more than a million barrels a day in each of the last three years. But executives say they believe production may begin to slow near the end of the year as the drilling of new wells declines.