Viscosity and retention of sulfonated polyacrylamide polymers at high temperature

Abstract

ABSTRACT:The viscosity and retention of several copolymers of acrylamide (AM) with sodium salt of 2-acrylamido-2-methylpropane sulfonic acid (PAMS), and also hydrolyzed polyacrylamide (HPAM) have been studied under aerobic condition with and without the sacrificial agent, isobutyl alcohol (IBA) added at a temperature of 80 C. Parallel experiments have been performed in synthetic seawater (SSW) and 5 wt % NaCl. The viscosity at high temperature has been studied as a function of aging time, shear rate, sulfonation degree, molecular weight, and concentration of IBA. The retention in porous medium for sulfonated polyacrylamide polymers was measured in core floods using outcrop Berea sandstone. For the studied polymer sacrificial agent may protect polymer structure at high temperature. Higher sacrificial agent concentration gives better thermal stability in both 5 wt % NaCl and SSW solvents. Sulfonation degree also has a direct effect on thermal stability, i.e., higher sulfonation degree lead to better thermal stability in terms of viscosity. By increasing temperature, less relative reduction in polymer solution viscosity was observed for the polymer with lower molecular weight. The presence of divalent ions at high temperature leads to strong reduction of HPAM polymer solution viscosity, but the viscosity is better maintained for PAMS copolymer solution at high temperature. The precipitation of HPAM first occurred after 3 months at 80 C and for PAMS copolymer with lowest sulfonation degree precipitation started after 7 months. For the studied polymers the retention was found to be relatively independent of temperature and compared to HPAM a much lower retention is observed for the sulfonated copolymers.

Review on Polymer Flooding: Rheology, Adsorption, Stability, and Field Applications of Various Polymer Systems

“…The main problems associated with xanthan gum are high cost, viscosity loss due to biochemical reactions, biodegradation, and injectivity issues due to cellular debris that may remain after manufacturing. 56,97,21,174 Xanthan gum is not suitable for reservoirs with temperatures above 93 • C. 101 Aqueous solutions of xanthan gum have a low elasticity, 49 and the bacterial degradation of xanthan gum can be reduced with formaldehyde under field conditions. 173 …”

“…The same solution lost one-third of its viscosity within 10 days when aged at 130 • C. Residual impurities of the polymerization process also cause thermal instability, 96 with a highly purified solution showing better thermal stability. Rashidi et al 97 investigated the thermal stability of AM-AMPS copolymer at different shear rates and sulfonation with and without the presence of isobutyl alcohol (IBA). The presence of IBA improved the thermal stability in an aerobic environment.…”

Efficient estimation of hydrolyzed polyacrylamide (HPAM) solution viscosity for enhanced oil recovery process by polymer flooding

“…A large number of investigations have been conducted to study the impact of polymer concentrations, shear rate, temperature, salt concentration, HPAM hydrolysis degree, and hardness on the solution viscosity as the main rheological property of HPAM solutions [5,7,[15][16][17][18][19][20][21][22][23]. Some researchers have undertaken a number of experimental investigations to examine the performance of Hydrophobically Associating Polyacrylamide (HAPAM) [24] and HPAM/Cr(III) [25] to improve the performance of HPAM components in EOR.…”

Experimental investigation of the effect of different process variables on the viscosity of sulfonated polyacrylamide copolymers

“…Literature shows that process variables, such as polymer concentration, shear-rate, sulfonation degree, salt concentration and molecular weight, have an influence on the polymer solution viscosity (Luo et al 2006;Rashidi et al 2011;Sheng 2011;Sorbie 1991). The main focus of this paper is to precisely assess the effects of the above-mentioned parameters on the polymer solution viscosity.…”