Cargando…

Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions

[Image: see text] A gel system composed of acrylamide (AM), N,N′-methylenebisAM (BIS), and ammonium persulfate ((NH(4))(2)S(2)O(8)) was developed and applied extensively in reservoirs to reduce water cut and increase oil production in mature fields. However, this gel system suffers from thermal stab...

Descripción completa

Detalles Bibliográficos
Autores principales: Xiong, Chunming, Wei, Falin, Li, Weitao, Liu, Pingde, Wu, Yong, Dai, Mingli, Chen, Jun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645078/
https://www.ncbi.nlm.nih.gov/pubmed/31459189
http://dx.doi.org/10.1021/acsomega.8b01205
_version_ 1783437385227304960
author Xiong, Chunming
Wei, Falin
Li, Weitao
Liu, Pingde
Wu, Yong
Dai, Mingli
Chen, Jun
author_facet Xiong, Chunming
Wei, Falin
Li, Weitao
Liu, Pingde
Wu, Yong
Dai, Mingli
Chen, Jun
author_sort Xiong, Chunming
collection PubMed
description [Image: see text] A gel system composed of acrylamide (AM), N,N′-methylenebisAM (BIS), and ammonium persulfate ((NH(4))(2)S(2)O(8)) was developed and applied extensively in reservoirs to reduce water cut and increase oil production in mature fields. However, this gel system suffers from thermal stability loss and syneresis at high temperatures that reduces its ability to control water flow. It has been widely accepted that the loss of gel thermal stability can be explained via three aspects: the rupture of polymer chains, the breakage of cross-linker chains, and hydrolysis of polymer. The mechanism of hydrogel syneresis through polymer hydrolysis has been investigated extensively in other publications. However, research on the other two mechanisms is quite limited. In this article, we conduct a series of experiments to demonstrate how the rupture of polymer and cross-linker chains leads to the hydrogel instability at high temperatures. Viscosity and energy-dispersive system measurements suggested that polyAM chains were disrupted by the oxidation reactions involving free radicals. The method to measure the cross-linking degree was established and in combination with X-ray photoelectron spectroscopy measurements, the results showed that cross-linker chains were broken as a result of weaker C–N bond resulting from positively charged mesomethylene carbon and hydrolysis of amide groups on the cross-linker. Because of the application of deionized water in the experiments, nuclear magnetic resonance and FTIR measurements showed that the hydrolysis degree of polymer was weak. Hence, our results verified that breakage of polymer and cross-linker chains led to the rupture of the gel network at high temperature. Besides, cross-linker chains may play a more important role in the thermal stability of the gel, which explains some work into high-temperature-resistant gels.
format Online
Article
Text
id pubmed-6645078
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher American Chemical Society
record_format MEDLINE/PubMed
spelling pubmed-66450782019-08-27 Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions Xiong, Chunming Wei, Falin Li, Weitao Liu, Pingde Wu, Yong Dai, Mingli Chen, Jun ACS Omega [Image: see text] A gel system composed of acrylamide (AM), N,N′-methylenebisAM (BIS), and ammonium persulfate ((NH(4))(2)S(2)O(8)) was developed and applied extensively in reservoirs to reduce water cut and increase oil production in mature fields. However, this gel system suffers from thermal stability loss and syneresis at high temperatures that reduces its ability to control water flow. It has been widely accepted that the loss of gel thermal stability can be explained via three aspects: the rupture of polymer chains, the breakage of cross-linker chains, and hydrolysis of polymer. The mechanism of hydrogel syneresis through polymer hydrolysis has been investigated extensively in other publications. However, research on the other two mechanisms is quite limited. In this article, we conduct a series of experiments to demonstrate how the rupture of polymer and cross-linker chains leads to the hydrogel instability at high temperatures. Viscosity and energy-dispersive system measurements suggested that polyAM chains were disrupted by the oxidation reactions involving free radicals. The method to measure the cross-linking degree was established and in combination with X-ray photoelectron spectroscopy measurements, the results showed that cross-linker chains were broken as a result of weaker C–N bond resulting from positively charged mesomethylene carbon and hydrolysis of amide groups on the cross-linker. Because of the application of deionized water in the experiments, nuclear magnetic resonance and FTIR measurements showed that the hydrolysis degree of polymer was weak. Hence, our results verified that breakage of polymer and cross-linker chains led to the rupture of the gel network at high temperature. Besides, cross-linker chains may play a more important role in the thermal stability of the gel, which explains some work into high-temperature-resistant gels. American Chemical Society 2018-09-06 /pmc/articles/PMC6645078/ /pubmed/31459189 http://dx.doi.org/10.1021/acsomega.8b01205 Text en Copyright © 2018 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Xiong, Chunming
Wei, Falin
Li, Weitao
Liu, Pingde
Wu, Yong
Dai, Mingli
Chen, Jun
Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions
title Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions
title_full Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions
title_fullStr Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions
title_full_unstemmed Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions
title_short Mechanism of Polyacrylamide Hydrogel Instability on High-Temperature Conditions
title_sort mechanism of polyacrylamide hydrogel instability on high-temperature conditions
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645078/
https://www.ncbi.nlm.nih.gov/pubmed/31459189
http://dx.doi.org/10.1021/acsomega.8b01205
work_keys_str_mv AT xiongchunming mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions
AT weifalin mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions
AT liweitao mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions
AT liupingde mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions
AT wuyong mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions
AT daimingli mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions
AT chenjun mechanismofpolyacrylamidehydrogelinstabilityonhightemperatureconditions