Copiapo, Chile (CNN) -- An oil drill that rescuers are using to reach the trapped miners in Chile could provide a faster solution than the other two methods they have employed.
The Plan C drill has previously been able to reach depths of 1,000 meters in 24 hours, according to a representative of the company overseeing technical aspects of the operation.
But officials do not know how long it will take the drill, which is normally used in very different circumstances to drill for oil, to reach the 33 men trapped 700 meters (2,300 feet) underground.
"Once we start drilling in earnest, I will have a much better idea of how fast we can make it down the 700 meters to the miners," said Juan Carlos Marin, a representative for Schlumberger who is in Chile to oversee technical aspects of the operation.
He said engineers are dealing with hard rock and a much smaller area than they normally encounter.
"When we drill for oil, we have a much bigger target area of perhaps 50 or 60 meters. Here we have a margin of error of just 4 meters," Marin said.
Four meters is the approximate width of the tunnels in the San Jose mine complex.
The need for precision in this drilling operation means the drill will move much more slowly, he said, but he gave no precise predictions.
"If we did not have such a specific objective at 700 meters, then we could do this in two days," he said. "But what changes all this is that we have to reach an objective with precision, and so we do not know how long that could take."
For now, the company has told Chilean officials that it could take 40 days to complete the work, he said. He did not say whether time it took to assemble the rig and drill the pilot hole was included in that timeframe.
The rig, which is owned by Canadian Precision Drilling, began operations Sunday and has drilled a pilot hole down 23 meters.
A pipe will now be placed in that pilot hole, which will be encased with a steel tube and cemented in. Andre Sougarret, coordinator of the rescue effort, said the rescue shaft once encased with steel piping would measure 23 inches.
Marin expects that work to be completed and drilling to begin in earnest within three days.
Sougarret said that serious drilling could begin as early as Tuesday night and that an average of 20 to 30 meters per day for the drill would be a "good average."
Two other drills are also trying to reach the miners, who have been trapped since the August 5 cave-in. The drills, dubbed Plan A and Plan B, each require two holes to be drilled and have been moving at a rate of 30 or 40 meters a day.
Plan A has drilled a 15-inch shaft to a depth of 351 meters, Sougarret said.
A 12-inch bore hole made by the Plan B drill reached the miners Friday, making it 623 meters into the mine. But it must be widened before the miners can squeeze through -- a process that should take a few weeks. At the full diameter of 28 inches, it has reached a depth of 50 meters, according to Sougarret.
Officials are planning how they will bring the miners to the surface once a bore hole is wide enough for the task. The daunting rescue may require an oxygen-fed cage that will haul them up one at a time.
Sougarret added that the largest of the miners measures 48 inches around the shoulders.
Previously, officials have said that the workers could be rescued, if all goes well, in late October or early November.
When asked whether the Plan C drill would be able to cover 100 meters a day, Marin said "ojala," Spanish for "I hope so."
It also means "that would be nice."
"When I look at their faces on their video they have sent to the surface, I would love to have them out by tomorrow," he said.
CNN's Esprit Smith contributed to this report.