Although millions of gallons of water will be needed for hydraulic fracturing as drilling booms throughout the Eagle Ford shale, the amount of water used for fracking will be much less than what’s needed by municipalities and for irrigation and industry in the region, an expert said.
“We have people coming into South Texas voicing gloom and doom,” said Darrell Brownlow, a principal at Intercoastal Inland Services LLC, a consulting firm.
“But let’s put our water use in perspective,” he said. “Look at the ratios,” he said to a packed meeting room on the opening day of Houston-based Hart Energy’s Developing Unconventional Gas Eagle Ford Conference & Exhibition that runs through midday Wednesday at the convention center.
Brownlow, a geologist who from 2000-2010 was Gov. Perry’s appointee to the Evergreen Underground Water Conservation District, said it’s only natural that in the middle of a drought people are concerned about water use, including for hydraulic fracturing.
But Brownlow said he’s telling concerned people: “The horse is not out of the barn. Don’t freak out. There is time to plan and we can update the (water) plans. We have a very active water-planning process that can take a look at these previously unseen demands, not just for energy but for municipal and agricultural interests. I have faith in the water-planning process.”
It takes about 4.7 million gallons of water to frack the average well in the Eagle Ford shale, a vast reservoir containing oil and natural gas that swoops beneath about 26 counties in South Texas. Estimates are that 25,000 wells may be drilled in the Eagle Ford shale over the next 20 years. They’ll require more than 15,000 acre-feet of water per year.
But that total is dwarfed by regionwide water usage, Brownlow said.
The South Texas water-management region that includes Bexar County uses 1.1 million acre-feet per year, while the entire South Texas region uses 4.2 million acre-feet of water per year.
That means that for every 1 acre-foot of water used in fracking, 280 acre-feet will be used for other purposes, he said.
In another comparison, Brownlow estimated that 83 wells, about the number to be drilled each year in each county in the heart of the shale, would require the same amount of water needed to grow 625 acres of corn.
The economic gain from the oil and gas is stupendous compared to growing corn.
The 83 wells would generate almost $2.5 billion, assuming the wells produce for 30 years at an average $100 a barrel for a barrel of oil or oil equivalent. The corn would net a grower $187,500, assuming a net price of $300 an acre for the grain.
Brownlow acknowledged, though, that “there will be challenges” in water planning and usage.
Throughout much of the Eagle Ford, the water source is the Carrizo aquifer, which underlies more than 80 percent of the shale reservoir, he said. It’s a vast reservoir that contains billions of acre-feet of water.
But the Carrizo doesn’t extend to the westernmost edge of the Eagle Ford or to parts of the eastern stretch of the play, so operators must truck water in, he said.
“And there will be conflicts. There are conflicts right now about municipal and irrigation uses,” he said.
The conference that sponsored Brownlow’s talk continues through midday Wednesday. Today, former Secretary of Defense Robert Gates will give the keynote address at noon. Other talks will focus on the geology of the Eagle Ford shale, the oil window of the reservoir, and pipeline companies’ expansion plans.