Is chitosan a green crosslinker for polyacrylamide gelation?

In many review articles, chitosan is also proposed as a green crosslinker for polyacrylamide (PAM) gelation for high-temperature reservoirs for conformance control applications ( Negi et al., 2021Magzoub et al., 2020Hamza et al., 2019El-Karsani et al., 2014Amir et al., 2019 ).

Can chitosan grafted polyacrylamide be used for water shutoff?

This paper uses one of the polysaccharides and proposes an environmentally friendly PPG for water shutoff applications in reservoirs of high temperature (≤130 °C) and high salinity (200,000 ppm), named chitosan grafted polyacrylamide crosslinked with N, N′-methylene bisacrylamide, synthesized chemically by microwave assisted method.

Which polymeric formulations are used to seal high permeability and fractured zones?

Polymeric formulations such as preformed particle gel (PPG), foamed gel, and in-situ crosslinked gel have proved their potential application in sealing high permeability and/or fractured zones. In addition, they are used for conformance control to enhance CO flooding sweep efficiency and storage efficiency ( Sun et al., 2020

Why are polysaccharides based gels weaker than covalent gels?

Polysaccharides-based gels prepared by physical crosslinking are weaker than the ones crosslinked by strong covalent bonding.

Can preformed particle gels be used for conformance control?

A recent and efficient technology for conformance control is the injection of preformed particle gels (PPGs), which results in a more practical production process. Nevertheless, existing treatments fail in high-temperature reservoirs, are extremely sensitive to salinity, and are hazardous.

Does swelling capacity affect gel strength in deionized water?

Since swelling capacity and gel strength have an inverse relationship, and as the developed Cs/PAMBA PPGs suggested to be insensitive to salinity with approximately the same swelling ratios, their gel strengths were almost similar in deionized water, and the other two brines of A and B.