One Hundred Million Barrels of Oil From Block 31 Unit

Duane's take

Here's my telling of what the official marker has to say, straight from Crane County, Texas. Now, picture this. It's November of 1945, somewhere out in the West Texas hardpan, about a mile to the northeast of where we're standing right now.

A crew drills down into the earth, deeper and deeper, until they hit the Devonian formation, about eight thousand five hundred feet below the surface. That well, University A No. 1, drilled by the Atlantic Richfield Company, turns out to be a discovery well. And friend, that is the beginning of one of the great oil stories in Texas history.

The land underneath all of this belongs to the University of Texas, a stretch the marker calls Block 31 Unit, seven thousand two hundred acres in area. Atlantic Richfield stayed on as the operator, and they were joined by Phillips Petroleum Company, Continental Oil Company, and Champlin Petroleum Company, all leasing that University of Texas land together. Seventy-two wells, each one reaching down roughly eight thousand five hundred feet, all punching into that same Devonian formation.

Now here is where the story gets interesting, because getting the oil out of subterranean rock is not as simple as just poking a hole and waiting. Over the years, the folks running this unit tried some unusual processes to squeeze every last barrel out of the reservoir. First, they injected high pressure natural gas down into the formation, using it to wash oil right out of the rock.

Then, when that got too costly, they switched to exhaust gas instead. Research, patience, and what the marker calls farsighted policies made unusually high recovery possible in this reservoir. And the Texas Railroad Commission, as the regulatory body overseeing oil production, along with the University of Texas and the unit's owners, all share the credit for the conservation and good management that made it happen.

So how much oil are we talking? By July 27, 1969, this single unit had produced one hundred million barrels of crude oil. One hundred million.

Then, in 1989, a supplemental plate was added to this marker, because the story wasn't finished. On October 17, 1987, the Block 31 Unit hit its second milestone. The two hundred millionth barrel of crude oil came up out of that Devonian formation.

One discovery well, drilled in November of 1945. Two hundred million barrels later, that well earned its name.

What the marker says

A discovery well completed in Nov. 1945 about a mile to the northeast has led to vast production of oil--one hundred million barrels by July 27, 1969. The discovery well, University A No.1 , was drilled by the Atlantic Richfield Company. This development is on land belonging to the University of Texas, designated as Block 31 Unit, and leased to Atlantic Richfield (the operator), Phillips Petroleum Company, Continental Oil Company and Champlin Petroleum Company. The unit--7,200 acres in area--has 72 wells approximately 8,500 feet deep, into the earth stratum known as the Devonian formation. Through the years, unusual processes were used to increase unit oil recovery. High pressure natural gas was injected, to wash oil from subterranean rock. Later, exhaust gas was injected instead of the costlier natural gas. Research and farsighted policies made possible unusually high recovery in this reservoir. Credit for the conservation and good management of this unit goes to the Texas Railroad Commission (as the regulatory body with oversight of oil production), the University of Texas and owners of the unit. (1969) supplemental plate added 1989: A second milestone was reached October 17, 1987, when the two hundred millionth barrel of crude oil was produced from the Block 31 Unit.