Seeking Lower-Cost Ways To Deal With Fracturing Water

Abstract

Unconventional Water The management of water used for fracturing oil and gas wells is all over the map. In Pennsylvania, most of the produced water is treated so it can be used again for fracturing, but some is cleaned to the point at which it meets the stringent requirements for river disposal. In Texas, fracturing fluids generally use fresh water, and what flows back to the surface is injected into a deep disposal well. A 2012 report, prepared by the Bureau of Economic Geology for the Texas Oil & Gas Association, titled Oil & Gas Water Use in Texas, puts the percentage of produced water recycled for fracturing in the Eagle Ford shale at 0%, and in the Permian Basin near Midland at 2%. In these arid regions fresh water is used by a wide margin. In the Eagle Ford, 20% of the water for fracturing came from brackish aquifers, and 30% in the Permian around Midland used water too salty to be potable. Things change fast in these booming plays. But the lead author of the report, Jean-Philippe Nicot, a research scientist at the Bureau of Economic Geology of The University of Texas at Austin, said: “I don’t think those numbers have changed much. There is likely some reuse/recycling in all plays, so 0% is probably not correct, but close to it.” For Michael Dunkel, director of sustainable development at Pioneer Natural Resources, past performance in places like the Permian is not a useful indicator of the future in an area where so many are looking for alternatives. “I am confident what we are seeing today is just at the starting gate and it will continue to evolve,” he said. Given the thousands of unconventional wells drilled, this may seem to be a slow evolution, but the staggering scale of these formations, particularly in the Permian, means operators such as Pioneer are just moving from scattered exploration drilling to concentrated development. “We will be drilling for 30-plus years out there,” Dunkel said. While he is confident the industry will change how it manages water for unconventional development, there are a lot of ways it can go from here. The decisions hinge on a complex mix of variables, which can be boiled down to a simple imperative: What is the lowest-cost option? The correct answers will vary from region to region, and from company to company depending on factors such as the scale of a company’s operation. Chesapeake Energy treats most of the water produced in its wells in Pennsylvania for reuse in fracturing with a small amount sent for disposal, said Rick McCurdy, manager of chemicals and water reclamation at Chesapeake Energy Corp. In south Texas most of the water is pumped from freshwater aquifers and produced water is injected into disposal wells.