Investigation of Optimum Polymerization Conditions for Synthesis of Cross-Linked Polyacrylamide-Amphoteric Surfmer Nanocomposites for Polymer Flooding in Sandstone Reservoirs

Abstract

Currently enhanced oil recovery (EOR) technology is getting more attention by many countries since energy crises are getting worse and frightening. Polymer flooding by hydrophobically associated polyacrylamides (HAPAM) and its modified silica nanocomposite are a widely implemented technique through enhanced oil recovery (EOR) technology. This polymers class can be synthesized by copolymerization of acrylamide (AM), reactive surfmer, functionalized silica nanoparticles, and a hydrophobic cross-linker moiety in the presence of water soluble initiator via heterogeneous emulsion polymerization technique, to form latexes that can be applied during polymer flooding. Chemical structure of the prepared copolymers was proven through different techniques such as Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic spectroscopy (1H&13C-NMR), and molecular weight was measured by gel permeation chromatography. Study of the effects of monomer, surfmer, cross-linker, silica, and initiator concentrations as well as reaction temperature was investigated to determine optimum polymerization conditions through single factor and orthogonal experiments. Evaluation of the prepared copolymers for enhancing recovered oil amount was evaluated by carrying out flooding experiments on one-dimensional sandstone model to determine recovery factor.

Synthetic and natural polyampholytes: Structural and behavioral similarity

“…Due to their salt and temperature resistance, quenched polyampholytes are widely applied in enhanced oil recovery (EOR) as thickening agents in brine solution 60‐67 . Hydrophobically associating polyampholytes may be especially effective viscosity enhancers in high salinity media and at high temperatures, as they combine self‐assembly and polyampholytic properties 68,69 . Application of hydrophobically modified and acrylamide‐based polyampholytes in EOR has been reviewed 52,70 .…”

Hydrophobic Polymers Flooding

“…Rheological properties were assessed in accordance with salinity and temperature tolerance, polymer concentration, and shear rates. Core flooding carried out via a linear pressurized packed model [9,[78][79][80]. Based on the experimental results, the following conclusions can be drawn:…”

“…Further discussions of chemical synthesis and spectroscopic characterization of surfmer, HAPAM copolymer, and nanocomposite by means of FTIR, 1 H-NMR, 13 C-NMR, transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) as well as optimum polymerization conditions are reported in our previous literature [9,78,80]. Moreover, critical micelle concentration, surface excess concentration, and surface area of prepared surfmer and original surfactant indicate higher surface activity of prepared surfmer, which increases latex stability [78].…”

“…(1) Improving volumetric sweeping efficiency by adjusting the oil/water mobility ratio through polymer flooding agents, which increase displacing fluid viscosity in order to modify the viscous forces being applied to drive oil out of the pores [8], thus increasing the produced crude oil amount. A polymer solution has increased viscosity and decreased relative permeability so it is an attractive option to decrease the mobility ratio and increase the volumetric sweep efficiency of the injection [9].…”

Emulsion Polymerization Mechanism

“…Emulsion polymerization carried out below the cloud temperature and above the Kraft temperature [5]. Polymerizable surfactants (surfactants with active double bond) such as sodium dodecyl allyl sulfosuccinate [13,[22][23][24]] also used to produce latexes with chemically bound surface-active groups [5,[25][26][27][28][29][30]31]. Polymerized surfactants (surfactants with active double bond) consist of amphipathic structure comprising hydrophobic tail and hydrophilic head group [32], in addition to polymerized vinyl groups [33] in their molecular structure, which acquire them unique physicochemical properties other than traditional surfactants moieties [34] such as;…”