Abstract

The Nature and Suitability of Brackish Groundwater as an Alternative Water Source for Hydraulic Fracturing Fluids, Midland Basin, Texas

Frankie R. Reyes¹, Mark A. Engle¹^,², Michael A. Jacobs³, and Lixin Jin¹
¹University of Texas at El Paso, Dept. of Geol. Sciences, El Paso, TX, 79968
²U.S. Geological Survey, Reston, VA 20192
³Pioneer Natural Resources USA, Inc., Midland, TX 79706

The significant water resource demands associated with hydrocarbon extraction are impacted by continuing water scarcity in the U.S. A combination of more efficient technologies and new water sources is needed to sustain the future of hydrocarbon extraction methods and reduce the demand on freshwater resources in the U.S. The Midland Basin, located in semi-arid far west Texas, is already impacted by limited water quality and quantity. Accordingly, it presents an ideal opportunity to explore alternative water resources, such as brackish groundwater, for use in hydraulic fracturing, which is a significant water consuming activity in the production of hydrocarbons. The purpose of this study is to characterize brackish groundwaters within the Midland Basin and evaluate their suitability for use in hydraulic fracturing for local hydrocarbon development.

Brackish groundwater systems are poorly studied in the United States, but represent a vast potential water resource. We will use well log and geochemical data to investigate the potential source and hydrogeology of Late Triassic Dockum Group groundwater in the Midland Basin. Additionally, we will investigate the source and geochemical reactions controlling the chemistry and variability of these groundwaters by analyzing a combination of major ions, and stable and radiogenic isotopes (δD, δ¹⁸O, ⁸⁷Sr/⁸⁶Sr). Well logs and pump test results from recently drilled wells will be used to understanding spatial variability in the structure and transmissivity of the Dockum hydrostratigraphic unit.

The feasibility of utilizing brackish groundwater for hydraulic fracturing is limited by a variety of chemical conditions including high alkaline earth metals, sulfate, and dissolved organic carbon concentration. Understanding how the composition of brackish groundwaters affects corrosion and scale during hydraulic fracturing will also be investigated using geochemical modeling. Findings from this research will provide important baseline data on potential beneficial use of brackish groundwaters for the oil and gas industry.

AAPG Search and Discovery Article #90164©2013 AAPG Southwest Section Meeting, Fredericksburg, Texas, April 6-10, 2013