Preparation and characterization of nanocomposite hydrogels based on polyacrylamide for enhanced oil recovery applications

Abstract

ABSTRACT:In the present work, attempts have been made to prepare nanocomposite type of hydrogels (NC gels) by crosslinking the polyacrylamide/montmorillonite (Na-MMT) clay aqueous solutions with chromium (III). The Xray diffraction patterns of the NC gels exhibited a significant increase in d 001 spacing between the clay layers, indicating the formation of intercalated as well as exfoliated type of morphology. Exfoliation of the clay layers through out the gel network was found to be predominated, which evidences the high interaction between the polyacrylamide segments and montmorillonite layers. Gelation time as well as variation of viscoelastic parameters such as storage modulus (GЈ) of the gel network during gelation process at 75°C was studied and followed by rheomechanical spectroscopy (RMS). The NC gels prepared with lower crosslinker concentration showed higher strength and elastic modulus compared with the similar but unfilled polyacrylamide gel. This distinct characteristic of the NC gels yields a gel network structure with high resistance towards syneresis at high temperature in the presence of the oil reservoir formation water. The effects of the composition, such as clay content, crosslinker concentration, and also water salinity upon the gelation rate, gel strength as well as rate of syneresis have been investigated. To optimize the injectivity of the intercalated polyacrylamide solution before the onset of gelation with the gel strength of the final developed gel, sodium lactate was employed as retarder. This was found to be effective to balance these two characteristics of the NC gels, which are aimed to be used for water shut-off and as profile modifier in enhanced oil recovery (EOR) process during water flooding process. The nanocomposite gels showed much more elasticity and extensibility at low crosslinker concentration compared with the similar but unfilled gel, which makes the NC gels suitable as an in-depth profile modifier, and also as an oil displacing agent in the heterogeneous oil reservoir in chemical EOR. Effects of the clay content on the thermal stability of the gel network have also been investigated by thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) has been performed upon the NC-gel samples.

Synthesis, characterization and evaluation of polyacrylamide graft starch/clay nanocomposite hydrogel system for enhanced oil recovery

“…The basal peak disappeared when MMT mixed with PAAm. This indicates that clay layers either were exfoliated or too low in content in the polymer (Zolfaghari et al 2006;. FTIR analyses were utilized to clarify grafting of starch onto polyacrylamide and MMT.…”

“…Several researchers have focused on studying nanocomposite hydrogels suitable for enhanced oil recovery applications due to their characteristic network structures Zolfaghari et al 2006). These nanocomposite hydrogels mainly consist of polymer chains connecting neighboring clay sheets .…”

“…These nanocomposite hydrogels mainly consist of polymer chains connecting neighboring clay sheets . Zolfaghari et al (2006) prepared hydrogels based on partially hydrolyzed polyacrylamide (PHPA), montmorillonite (nanoclay) and Cr (III) (as a crosslinker). They showed that the nanocomposite gels prepared with a low crosslinker concentration had high gel strength and modulus, which results in high syneresis at high temperatures compared with the unfilled polyacrylamide gel.…”

Synthetic polyacrylamide as a potential flocculent to remove commercial chromium(III) oxide from aqueous suspension

“…PAM is also used as a dispersant, spatial stabilizer and thickener (Sojka and Entry 2000;Entry et al 2002;Zolfaghari et al 2006;Xia 2007;Yuan et al 2011).…”

Preparation and Performance of a Novel Water‐Soluble Cationic Polymer Containing β‐Cyclodextrin

“…With the rapid development of economy, water-soluble polymer materials are widely used in all fields of national economy, especially in the oil industry, water treatment, and papermaking industry [1][2][3][4][5][6][7]. Due to the good performance of the viscoelasticity in chemical flooding processes, water-soluble acrylamide polymers are attracting increasing attention [8].…”