The sea itself is shallow and marshy, and the wind blows the water around so what is covered one day may not be the next. “I’ve been in the maritime industry for 40 years, and this is the strangest place I have ever worked,” said Mark Bacon , a shipping manager.

At night, Nanna Heitmann, a photographer, and I settled into a vast complex of star-shaped dormitories. Long buildings with sleeping quarters holding a total of 5,000 beds led into circular structures where meals were served.

The camp seemed an egalitarian place; expats and Kazakh engineers lived there and met at meals.

My room was clean but basic with a single bed, a wooden desk and a closet. The only decoration was a rug with the letters T.C.O. woven into it for Tengizchevroil, the company that runs the field. Uniformed security people were on patrol, opening and shutting doors and making the floors creak at night.

To our surprise, there were bars that served beer and wine. One evening Ms. Heitmann, who speaks Russian, which is the language of business in Kazakhstan, arranged for us to be invited to a birthday party thrown by a group of young workers. With their holidays coming soon, they were shaking off weeks of tight control and rules in a beery cigarette-fueled blowout.

Many of the people at Tengiz work a 28-days-on, 28-days-off rotation. It sounds like a lot of vacation, but long days are required on the job. Occasions like spouses’ birthdays and Christmas are missed, and it is easy to see how years of life in these camps could wear on the soul.

On the other hand, there was a sense around the oil field that Tengiz was “one of the most exciting projects and places to be on the planet,” as Jim Mayeaux, a senior construction manager, said. Word had come to people like Tom Koren, the chief engineer , from higher up the oil hierarchy that they would be wise to sign up.

Would it be the last project? Probably not. But Mike Rogers, a seasoned executive at Fluor, one of the main contractors, noted that there were “a lot of gray hairs” on this job. For these veterans the campaign on the Caspian might well be their last.