The Carrizo Wilcox aquifer in South Texas appears to contain enough water to support oil and gas drilling, including hydraulic fracturing in the Eagle Ford shale, along with other anticipated uses, said Texas Railroad Commissioner David Porter.
An Eagle Ford taskforce reached that conclusion early this year, said Porter who spoke in Houston Feb. 27 during an Infocast conference on water management for shale plays. The taskforce continues to meet monthly to examine any water issues in South Texas, he said.
“We will continue to study best practices for water management in the region to help mitigate any future issues,” Porter said, adding that the taskforce was formed in response to concerns about how fracing might affect water levels in the aquifer.
Critics of fracing have also suggested chemicals used in frac fluid could contaminate underground water supplies.
The taskforce found that drilling and completions in the Eagle Ford account for 6% of water demand in South Texas. Irrigation accounts for 64%, and municipal uses account for 17%.
The oil and gas industry also has reduced the volume of water used to frac Eagle Ford wells. Industry reports it now uses 11 acre-ft of water to complete the average Eagle Ford well, down from 15 acre-ft used 18 months ago, the taskforce reported.
Industry expects 2,600-2,800 wells/year will be completed in the Eagle Ford shale at peak demand, which translates into about 30,000 acre-ft of water/year during the heaviest point of development of the Eagle Ford shale. In 2008, the Carrizo Wilcox aquifer contained 540,000 acre-ft of available water.
Eagle Ford development peak demand is expected in the next 2 decades, industry spokesmen have said.
Porter said some companies are looking into using brackish water for fracing instead of fresh water, which could reduce demand on the Carrizo Wilcox aquifer.
“I think industry needs to be commended for trying to reduce its footprint,” Porter said.
RRC is considering new water recycling rules for the state, and a public comment period will start once a draft of the proposed rules becomes available, Porter said. The next Texas legislative session is scheduled for January 2013.
Local groundwater conservation districts are monitoring water usage in the region, Porter noted.
Historically during periods of drought such as South Texas recently experienced, water levels will decline until normal rain patterns return. The Carrizo Wilcox aquifer typically recharges to pre-drought water levels.
In September 2011, the Texas Water Development board released a draft of its 2012 Texas water plan, which the board updates every 5 years.
The water plan draft said 56% of Texas water goes to commercial crops, 26.9% to cities and public water systems, 9.6% to manufacturing and refineries, 4.1% to power generation, 1.8% to livestock, and 1.6% to mining, which includes oil and gas drilling.
The water development board said fracing is a recent issue and therefore was not integrated into the report.
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