Nanoscale Polyacrylamide Copolymer/Silica Hydrogel Microspheres with High Compressive Strength and Satisfactory Dispersion Stability for Efficient Profile Control and Plugging

Abstract

Polyacrylamide (PAM)-based microspheres are commonly used as water plugging and profile control agents, but the poor mechanical strength and few studies on the dispersion stability, both of which are closely related to the profile control performance, limit the application of microspheres. Herein, we synthesize nanoscale PAM-based copolymer hydrogel microspheres with an inverse microemulsion copolymerization of acrylamide (AM) and 2-methyl-2-acrylic amide propyl sulfonic acid (AMPS) in the presence of vinyl-functionalized silica nanoparticles (VSNPs). The results show that a small amount of VSNPs (1.0 wt %) increases the compressive strength of the hydrogel by 0.6 times. The swollen nanoscale PAM/silica hydrogel microspheres show good dispersion stability. VSNPs significantly improve the elasticity of the hydrogel microspheres, and their dispersion stability under high temperature and high-salinity conditions. The simulation evaluation of core plugging suggests that the plugging rate of PAM-based polymer/silica hybrid microspheres with addition of 0.7 wt % VSNPs increases from 80% to 92% compared to neat polymer microspheres. This work provides a novel design of nanoscale cross-linked microspheres for deep profile control in different geological environments.

Effect of polyacrylamide morphology templated using lyotropic liquid crystal on the proton conductivity of acid hydrogels

“…5, the storage ( G ′) and loss ( G ′′) moduli of both hydrogels increased with increasing frequency, similar to most PAM hydrogels. 19–21 G ′ was always higher than G ′′ over the measured angular frequency range, indicating that the elastic deformation of polymeric networks in the hydrogels overwhelmed the plastic one. 22 Meanwhile, the G ′ of G LLC-random was higher than that of G LLC-ordered probably because the isotropic state resulted in more uniform crosslinking to afford more robust hydrogels.…”

Mesomorphic Polymer Hydrogel Stabilizing Ionic Surfactant Self-Assembly for Fuel Cells

“…In this case, the lyotropic lamellas reoriented repeatedly to respond to the oscillatory shear at such low frequencies like the thermotropic LCs loaded in the display cells reorientated under the applied voltage, consuming energies to weaken the moduli of PAM-ImHS . At high frequencies (ω > 60 rad s –1 ), the L α LLC responded little to the shearing so that G ′ and G ″ of PAM-ImHS increased with the increase in frequency like those of normal polyacrylamide hydrogels. − The loss factor (tan δ) exhibited a peak at a frequency of 60 rad s –1 , corresponding to the transition from the LLC dominated behavior to the polymer dominated behavior. G ′ and G ″ of PAM-ImHS were 2 orders of magnitude higher than those of physical LLC gels, ,, enabling toleration of stronger external forces.…”

Preparation and Properties of Double Network Hydrogel with High Compressive Strength

“…in poor mechanical properties and the inability to meet the requirements of waterplugging strength [16,17]. In addition, the viscosity of the pre-polymerization solution before the formation of hydrogel is relatively high and cannot enter the underground smoothly to achieve the water shutoff effect during injection into the oil well.…”

“…Therefore, hydrogels can be applied to the field of water plugging in oil fields [ 13 ]. Although hydrogel has been used in the field of oil field water plugging [ 14 , 15 ], due to the uneven network structure of the traditional single network hydrogel plugging agent, it will cause permanent damage under external force, resulting in poor mechanical properties and the inability to meet the requirements of water–plugging strength [ 16 , 17 ]. In addition, the viscosity of the pre–polymerization solution before the formation of hydrogel is relatively high and cannot enter the underground smoothly to achieve the water shutoff effect during injection into the oil well.…”