Investigation of the degradation and stability of acrylamide-based polymers in acid solution: Functional monomer modified polyacrylamide

Costa

J of Applied Polymer Sci

et al. 2019

Partially hydrolyzed polyacrylamide (HPAM) is the water-soluble polymer most often used in flooding applications in the petroleum industry. However, in aqueous solutions at high temperatures, HPAM undergoes hydrolysis of the lateral amide groups, and the presence of salts in the solution can lead to precipitation of this polymer. Therefore, a method was developed to monitor the thermal stability of HPAM solutions in different saline environments and varying temperatures. The proposed test method involved measurements of intrinsic viscosity as a function of time and determination of the degree of hydrolysis of the HPAM by elemental analysis. The results obtained indicated that the presence of divalent cations (Ca +2 and Mg +2 ) negatively influenced the intrinsic viscosity of the solutions and in some systems led to precocious precipitation of the polymer in environments with higher concentrations of these cations. The hydrolysis reaction of the amide groups to the acrylate groups of the HPAM chain was significantly affected by rising temperature: at 50 C, hydrolysis occurred, but not as significantly as at 70, 85, 90, and 95 C. Hydrolysis up to 84% was observed for solutions processed at 90 C. The results also indicated limits of hardness for the brine at some temperatures: 1353 ppm for 95 C and 2867 ppm for 70 C. For brine containing 13,610 ppm or more of divalent cations, hydrolysis and precipitation of the polymer were not observed at 50 C.

Section: Introductionmentioning

confidence: 99%

Hydrolysis and thermal stability of partially hydrolyzed polyacrylamide in high‐salinity environments

Costa

J of Applied Polymer Sci

et al. 2019

J of Applied Polymer Sci

“…Moreover, polymers are used widely as acid mud for drilling, fracturing, and acidizing during oil exploration, since they can increase viscosity, filtration loss, flow regulation, and have other functions . Polyacrylamide (PAM) is the most often‐used polymer in oil industry applications because of the promising rheological properties of polymer solution and the relatively low price . However, the efficiency of conventional polymers, for example, PAM significantly is reduced at harsh environment of high salinity‐high temperature (HS‐HT) or variate pH because of degradation or precipitation …”

Section: Introductionmentioning

confidence: 99%

Improved rheological properties and stability of multiwalled carbon nanotubes/polymer in harsh environment

Nourafkan

Haruna

Gardy

et al. 2018

This work aims to improve the rheological properties and stability of multiwalled carbon nanotubes (MWCNTs)/acrylamide (AA) base skeleton polymer blends at harsh environment of high salinity‐high temperature (HS‐HT) or various pH. Different co/terpolymers have been accomplished to modify the structure of AA polymer by free‐radical copolymerization of AA‐based monomers. Anionic, cationic, and hydrophobic functional groups were used for the synthesis of polyelectrolyte, polyampholytic, and partially hydrophobic AA polymer types. The conversion, molecular weight, and poly dispersity of co/terpolymers have been evaluated by nuclear magnetic resonance (1H‐NMR), gel permeation chromatography, and differential scanning calorimetry analysis. The effects of sonication power, concentration of polymer, and concentration of MWCNTs were also investigated on rheological behavior of co/terpolymers. The results show that negative polyelectrolyte and polyampholytic polymers are the best candidates for the improvement of MWCNTs/polymer stability and viscosity at HS‐HT and alkali environment, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47205.

Polymers for Advanced Techs

“…In order to apply the degelling process, the solution containing the degelling agent of citric acid (C 6 H 8 O 7 ) was added to the gel …”

Section: Methodsmentioning

confidence: 99%

“…In order to apply the degelling process, the solution containing the degelling agent of citric acid (C 6 H 8 O 7 ) was added to the gel. 17 Thus, the designed concentration of the degelling agent was solved in distilled water. Then, the desired weight ratio was added to the polymer gel sample, and again it was kept in oven at 90°C.…”

Section: Degellingmentioning

confidence: 99%

Experimental study of polyacrylamide gel in close‐in well operation

Hajipour

Salehi²,

Sefti

et al. 2017

An optimized polymer gel, known as temporary gel, based on polyacrylamide sulfonated copolymer, and a chromium acetate hydroxide were synthesized to close‐in the wells during applying well servicing work. Based on bottle tests, polymer gel with 28 000 ppm of polymer concentration, and 0.105 ratio of crosslinker to polymer, was selected. The pressure effect within the range of 1000 to 4000 psi indicated not impressive effect of pressure on the gel properties. As the results of creep test clarified, yield strength of the gel was measured at temperature of 90°C, and 2000 Pa. Moreover, the results of an experiment under simulated well condition showed a linear correlation between the height of polymer gel column, and the strength and persistence of gel against fluid pressure. At last, process of degelling with 40 g of optimum gel was performed using 14 g of 30 wt% solution of citric acid during 4 hours.