The Analysis of Fresh and Produced Waters in Hydraulic Fracturing Fluids

Determining the composition of fresh and produced waters used in fracking activities is crucial to investigate additive performance for optimizing extraction processes, to determine recyclability for minimizing operational costs, and to reduce potential effects on the ecosystem for safe disposal. Typically, fracking fluids exhibit high total dissolved solids (TDS), high organic residual, and high particulate content, which contribute to the challenge of composition analysis. In addition, the composition of fracking fluids has been observed to depend on the geological site and can significantly vary from one site to the other. Thus, it is important to have a robust plasma and a wide operating range to accurately and precisely measure concentrations in the range of µg/L to g/L under extreme matrix conditions. This study demonstrates the accuracy for standard certified reference materials, long-term stabilities, and excellent analytical spike recoveries, all within ± 20%, of fracking fluids from Permian Basin, Texas, United States, using the inductively coupled plasma – optical emission spectroscopy (ICP-OES) equipped with an autosampler and a salt kit introduction system. We present the determination of trace to major concentration levels of elements with a precision of < 3% relative standard deviation (RSD) achieved using the dual view plus feature of the PQ9100E. The high-frequency generator offers a plasma that is highly robust, ensuring consistent and stable signal intensity. These findings present a promise for the direct analysis of fracking fluids and to similar research and industry applications dealing with chemical analysis under extreme matrix conditions.