Gas well treated with 100% reused frac fluid

摘要

Reusing frac fluid benefits environment, saves water, and precludes disposal. Regulatory agencies, landowners, citizens concerned about environmental impact, and municipalities concerned about supplies of freshwater are drivers behind industry efforts to reuse water from which fracture fluids are prepared. Operating companies and other well-service companies have approached the problem of renewable freshwater supply by separating, filtering, and even distilling or crystallizing produced formation waters and frac-fluid flowback waters to purify them for future use or surface discharge. The four-component system (FCS) enables use of frac-fluid mix waters that do not require high-purity freshwater. The source waters are monovalent and anion tolerant in the presence of specific ratios of divalent cations (brine up to 12% NaCl and sulfate concentrations > 6%). Source waters also must be pH tolerant. Four subsystems that play key, synergistic roles in preparing frac fluid from flow-back and produced waters include.