Prevention of network destruction of partially hydrolyzed polyacrylamide (HPAM): Effects of salt, temperature, and fumed silica nanoparticles

Abstract

Polymer flooding is one of the most effective enhanced oil recovery (EOR) methods. High temperature and a high salt content in oil reservoirs significantly decrease the performance of polymer flooding. In this work, the viscoelastic properties of a partially hydrolyzed polyacrylamide (HPAM) solution with and without salt (NaCl) and at two different temperatures (35 °C and 70 °C) were evaluated using rheological approaches. Two fumed silica nanoparticles (NPs) featuring different surface chemistries were used, and their ability to prevent destruction of the polymer network structure against salt addition and temperature increase was investigated. Linear rheological tests (frequency sweep, creep, and creep recovery) and nonlinear rheological tests (large amplitude oscillatory shear) were employed to evaluate the network structure of these systems. The results showed that either adding salt or increasing the temperature destroyed the mechanical integrity of the HPAM 3-dimensional elastic network. However, the introduction of both types of NPs at a sufficient concentration maintained the network structure of HPAM solutions in the small deformation region. In the large deformation region, it was shown that the extent of intra-cycle shear-thickening behavior in the HPAM solution (T = 35 °C and without any salt) decreased by incorporating salt or by increasing the temperature. Moreover, upon incorporating either of the NPs to the HPAM solution, the nonlinear viscoelastic behavior dramatically changed, and the critical strain (linear to nonlinear transition) decreased to a much lower strain amplitude. The outcomes of this study will help petroleum scientists to design more efficient EOR methods.

Structural Characterization of CVD Custom-Synthesized Carbon Nanotube/Polymer Nanocomposites in Large-Amplitude Oscillatory Shear (LAOS) Mode: Effect of Dispersion Characteristics in Confined Geometries

“…Given the limitations of SAOS, and to simulate large-deformation industrial processing conditions, large-amplitude oscillatory shear (LAOS) flow has drawn great interest. Additionally, as the strain amplitude and frequency can be controlled independently, LAOS flow covers a wide spectrum of nonlinear situations with respect to time and deformation. , Considering the aforementioned reasons, over the past decade, LAOS has been extensively employed to study nonlinear viscoelasticity to detect any changes in topology, morphology, concentration, and so forth in a variety of systems, such as polymer solutions, , polymer nanocomposites, and polymer hydrogels …”

Morphology Evolution, Molecular Simulation, Electrical Properties, and Rheology of Carbon Nanotube/Polypropylene/Polystyrene Blend Nanocomposites: Effect of Molecular Interaction between Styrene-Butadiene Block Copolymer and Carbon Nanotube

“…In our previous works we showed the sensitivity of intra-cycle nonlinear viscoelastic response to subtle changes in the microstructure of different systems [ 74 , 75 , 76 , 77 , 78 , 79 , 80 ]. Hence, more information regarding the morphological changes of polymer blends with and without copolymers based on intra-cycle nonlinear viscoelasticity is provided in this section.…”

Impact of PAM-Grafted Nanoparticles on the Performance of Hydrolyzed Polyacrylamide Solutions for Heavy Oil Recovery at Different Salinities

“…The flow curves of unmodified TiO 2 and Al 2 O 3 NPs were not measured because of the low dispersivity of the NPs into the polymer solution, as seen in Figure . The pseudoplastic behavior of HPAM solutions is suppressed by the presence of electrolytes. ,− Relatively high concentrations of Na + neutralize part of the negative charges of the COO – groups on the polymer chain reducing the hydrodynamic volume of the chain as well as the degree of polymer entanglement. Both effects lead to the reduction of the solution viscosity as well as its dependence on the shear rate, as seen in Figure .…”

“…The current limits for polymer flooding are summarized by Sheng and co-workers and Delamaide . The addition of metal oxide NPs have been proposed to address polyacrylamides performance limitations. − The nanohybrids can be prepared by two methods: (1) mixing the polymer and the NPs ,,− or (2) grafting of the polymer onto the NP surface. − …”