November 24, 2004

By BJ Weiner
Public Affairs Officer
U.S. Army Corps of Engineers
Gulf Region District South

Preserve the reservoir.

That’s what water injection systems are for – to maintain oil reservoir pressure by replacing the oil that is withdrawn with treated water.

This past month, the Southern Oil Company of Basrah took ownership of the restored water injection system at the Qarmat Ali Water Treatment Plant on behalf of the Ministry of Oil in the new Iraq government.

To understand the process, one has to understand Oil 101, said Marcia Meekins, oil area engineer. Oil does not sit in large pools beneath the ground; rather, it is embedded in porous rock. “It’s not like the ‘Beverly Hillbillies, it doesn’t just bubble out of the ground. You have to drill down into these oil deposits through the rock.” she said.

As the oil is extracted, the reservoir loses pressure, according to Meekins. To preserve the life of the reservoir, water is injected into the rock to replace the pressure created by the oil.

“You have to strategically do this,” she said.” You have to inject the water in the right place, using the right amount of water, and you have to drive that water to the wellhead to equalize the pressure as you move the oil. That’s the object of the game.”

Meekins said that the Qarmat plant feeds Iraq ’s Rumaylah Reservoir. First tapped in the 1950s by the British, the reservoir splits into two fields; one in the south or and one in the north, Rumaylah South and North respectively.

“We spent about $225 million dollars which includes the power to do the water injection work, and there is talk about spending more money because the water injection is Iraq ’s first priority,” said Meekins.

Designed to process raw river water from a tributary of the Euphrates River , Qarmat Ali plant works as follows.

Treating the water first removes small solids from the river that could plug the reservoir pores if it builds up.  Water treatment also controls the acidity level and stymies bacterial growth. Left untreated, the reservoir could clog, not only reducing the oil flow, but requiring well repairs, re-perforating the well or, at worst having to redrill the well, according to a report done by Kellogg, Brown and Root (KBR), which began construction on the treatment plant in March 2003 at the direction of the U.S. Army Corps of Engineers. 

Qarmat Ali uses several pumps to draw, treat, and inject water. Stage One pumps draw the water from the river and pump it to elevated holding tanks. After being mixed, settled and filtered, the water is stored. Stage Two pumps shoot the stored water from the plant to a series of cluster pump stations to be injected into the oil reservoir.

Restoring the Qarmat Ali plant marks the largest project completion in the oil program thus far, said Meekins. “Most of our projects are centered on two goals,” she said. “One is to increase the export of crude oil to three million barrels a day. Right now, it puts out less than two.”

The second goal aims at increasing the production of liquid petroleum gas (LPG) to 3,000 metric tons a day, according to Meekins. Iraq’s current LPG production rests between four and six metric tons, depending on the time of year. “Right now, they have to import LPG,” she said. “LPG is what we would call propane. And that is used for cooking and for heating.”

Meekins emphasized that all projects in the oil sector forecast a good economic future for Iraq . “We don’t have any project here that’s not potentially a winner,” she said. “Not one.”