The record-breaking drought gripping Texas has the state's reservoir/aquifer managers eyeing water levels and issuing warnings. But lower water reserves apparently have not seriously affected oil and gas activities in the state, at least not yet.
In the Barnett Shale in North Texas producer water comes about half and half from surface sources and from underground aquifers, Robert Mace, deputy executive administrator with the Texas Water Board, told NGI's Shale Daily. In the Eagle Ford Shale of South Texas, producers rely more heavily on the sandstone aquifer below their feet, he said.
Surface water resources are more heavily impacted by droughts, Mace said. The Texas Commission on Environmental Quality (TCEQ) administers permitting for access to surface water. In a written response to questions, a TCEQ spokeswoman did allow that "some [producer] temporary water use permits have been suspended," but she did not provide any details.
Anadarko Petroleum Corp. said its activities have not been curtailed by the drought; however, the company is taking steps to be more mindful of the amount of water it uses in drilling and hydraulic fracturing (fracking) operations. The company gets water from the Carrizo-Wilcox Aquifer and from the Rio Grande.
"We are in the process of installing metering devices on our wells to measure the amount of water we draw for our operations to ensure water is managed in a responsible way," said Anadarko spokesman Brian Cain. The company is also rebuilding roads with limestone, allowing for dust management without having to use water, he said. "We work cooperatively with officials at the Wintergarden Groundwater Conservation District, and we share withdrawal data in an effort to help authorities monitor water levels and usage."
Ed Walker is manager of the Wintergarden District and overseas the Carrizo-Wilcox Aquifer. "Water levels, at least in the confined portion of the Carrizo, are at an all-time low, but, you know, by 20-25 feet, which is not a horrendous amount. But they're 20-25 feet lower than we've ever seen them in the past due to previous droughts," Walker told NGI's Shale Daily.
Besides Anadarko, other big producers accessing the aquifer are Chesapeake Energy Corp. and EOG Resources Corp., Walker said. His district covers La Salle, Dimmit and Zavala counties -- Eagle Ford Shale country in South Texas. La Salle and Dimmit have the most oilfield activity of the three.
Walker said his office is in the process of developing a drought contingency plan that would specify slowing of pumping from the aquifer, triggered by declining water levels, in times of drought. "Before we wreck the train, let's slow it down," he said of the idea behind the plan.
If "the aquifer goes dry, [oil and gas producers] are in as much trouble as anyone because they can't drill without it. So they're keenly aware of the concerns," he said.
When farmers, ranchers and homeowners see huge trucks driving by hauling water for fracking, they might be inclined to think that the oil and gas industry is using the majority of the water available, whether it be from aquifers or reservoirs. However, in reality energy patch usage is but a fraction of what is used for agricultural purposes, Mace said.
"The agricultural use is still pretty high compared to what the producers are using for fracking," he said. Based on research by the Bureau of Economic Geology at the University of Texas at Austin, Mace said water usage for fracking in Texas is expected to peak around 2031. At that time it is estimated such use will still only be equivalent to about 20% of the water used for agriculture, Mace said.
And water usage for fracking can vary depending on the play, Mace said. For instance, wells in the Pearsall/Eagle Ford Shale can require one million to 13 million gallons each to frack. In the Haynesville the figure is one million to 10 million gallons. However, in the Barnett Shale individual wells can be fracked with three million to four million gallons, Mace said.