Technology Focus: Water Management (December 2014)

Abstract

Technology Focus The demands for fresh water used in hydraulic-fracturing operations are placing constraints on water resources in some regions of the United States. Because of the high volumes of fresh water needed for hydraulic fracturing, the competing demand driven by industrial, municipal, and agricultural users has decreased the availability of fresh water and increased associated costs. Along with higher acquisition costs for fresh water, produced-water-disposal costs also have increased. To overcome these challenges, operators are using alternative methods of water management, including recycling and reusing produced water, to help reduce the total amount of fresh water required for their fracturing operations and, at the same time, reduce the amount of produced water that must be transported, treated, and disposed of. If the produced water is not recycled, the water is pumped into disposal wells. This practice has become a topic of public concern after reports of earthquakes began approximately 4 years ago in the central United States, where disposal wells are heavily used. Research conducted by the US Geological Survey and universities suggests that the increased injection of produced water from oil and gas operations near fault zones may be inducing earthquakes. Reclaiming produced water as a base fluid for hydraulic fracturing not only helps alleviate the oil and gas industry’s dependence on fresh water but also lowers the overall cost of fracturing. Produced water is usually composed of formation water and injected fluids from previous fracturing treatments. It can contain hydrocarbon and high levels of total dissolved solids (TDS), along with suspended solids and residual production chemicals. To reuse high-TDS produced water effectively in crosslinked-gel- based hydraulic-fracturing fluids, the water must first be treated. The goal of treatment is to control ions that hinder the development of the stable crosslinked fluid or that cause scale buildup in the wellbore. In response, a growing group of chemical suppliers, researchers, and service companies is on a mission to develop chemicals that will enable guar to hydrate and crosslink with boron crosslinker in untreated, high- TDS produced waters and yield a stable crosslinked fracturing fluid. The papers featured this month deal with water management and produced-water- treatment technologies. I urge you to look at OnePetro, the SPE online library, and download papers. You will find updates on best practices, case studies, new treatment technologies, and much more. JPT Recommended additional reading at OnePetro: www.onepetro.org. SPE 168520 One Company’s Upstream- Water-Resources-Management Guide by Stuart R.D. Lunn, Imperial Oil, et al. SPE 168401 Chevron San Ardo Facility Unit Beneficial Produced-Water Reuse for Irrigation by James E. Myers, Chevron SPE 168568 Appalachia Shale-Gas- Water Management Best Practices by Sean Beecroft, Chevron, et al. SPE 168469 Water Worth Waiting for: Smart Water Management Reduces Environmental Impact by S. Monroe, Baker Hughes, et al. SPE 165138 Produced-Water- Reinjection Design and Uncertainties Assessment by Jalel Ochi, Total, et al.