Table 1.
Formulation of ionic mother liquor.
Table 2.
Properties of simulated fracturing fluid.
Fig 1.
FE-SEM images of the original fracturing fluid at (a, b) low and (c, d) high magnifications. EDX Mapping results of the original fracturing fluid: (e) Mapping of all elements, (f) Mapping of Cl, O, Na and Ca.
Fig 2.
(a) FTIR spectra of the original fracturing fluid and pure HPG. (b) Schematic of broken keys for HPG.
Fig 3.
XPS full-scan spectrum of (a) simulated fracturing fluid-0 and (d) simulated fracturing fluid (after gel-breaking). High-solution C 1s XPS spectra of (b) simulated fracturing fluid-0 and (e) simulated fracturing fluid. High-solution N 1s XPS spectra of (c) simulated fracturing fluid-0 and (f) simulated fracturing fluid.
Fig 4.
Molecular weight (MW) distributions of organic matter in the (a) pure HPG (b) simulated fracturing fluid-0 and (c) simulated fracturing fluid. Five MW fractions (<1 kDa, 1–10 kDa, 10–100 kDa, 100–1000 kDa, and>1000 kDa) were identified in the pure HPG, simulated fracturing fluid-0 and simulated fracturing fluid.
Table 3.
The parameter values of HPG E-DLVO model.
Fig 5.
Interaction energy curves between HPG colloidal particles.
Fig 6.
(a) The flocculation efficiency, (b) TOC content and removal efficiency of different flocculants after treating simulated fracturing fluid.