Polymeric gels have been an important category for material scientists due its versatile structural features. Hence, hydrogels are being used to reduce excess production water in oil reservoirs. In this work, cross-linked partially hydrolyzed polyacrylamide (HPAM) composite hydrogels impregnated with bentonite clay (Bent) and bentonite clay modified (Orgbentent) with the surfactant hexadecyltrimethylammonium bromide were synthesized and characterized as a sealing agent in high water producing permeable zones in the petroleum industry. The concept of utilizing hydrophobically modified clay as an inorganic additive in the hydrogel matrix emanates from the fact that this additive exhibit greater interaction with the polymer chains. These interactions can promote the inherent properties of the hydrogel. Polyethyleneimine (PEI) was chosen as the cross-linking agent. HPAM/PEI conventional hydrogels and HPAM/PEI/Bent and HPAM/PEI/Orgbent at 100 mg•L −1 clay were synthesized. The developed hydrogels were characterized by a hybrid rheometer and Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) instruments. Rheological results reveal that the (HPAM/PEI/Bent-3 and HPAM/PEI/Orgbent-3) composite hydrogels showed higher elastic modulus (G′) and durability in the studied conditions (stable at 30 days) than conventional ones (HPAM/PEI), indicating the dispersion and reinforcing effect of clay. The functional groups of these hydrogels were confirmed by FTIR, and TGA demonstrated the structural reinforcement due to the presence of the clays, which had lower weight loss than the conventional hydrogel. The hydrogel morphologies were analyzed by SEM, and the results corroborated with those obtained by TGA, indicating better structural reinforcement when using organophilic clay.

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High water production and low oil recovery are attributable to reservoir heterogeneity, making extraction economically inefficient. To improve oil production, it is important to solve permeability issues, to allow a more uniform and efficient sweep. In recent years, several studies of preformed particle gel (PPG) have been performed reduce reservoir heterogeneity and enhance oil recovery. In this work, the effect of coal fly ash (CFA) on hydrolyzed polyacrylamide (PHPA) crosslinked with polyethyleneimine PPG were evaluated regarding thermal, rheological, and structural properties. The rheological results showed an increase in elastic behavior with the presence of CFA. Thermal analysis revealed degradation resistance of 271% with only 1.0% CFA. The swelling test proved that the presence of CFA supports the absorption of a brine solution. The results suggest a significant increase in properties assessed with small CFA contents due to a strong interaction between CFA and three‐dimensional polymer networks.

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No cenário energético mundial, as companhias petrolíferas exibem enormes gastos com tecnologias em busca de novas regiões para exploração de petróleo. Portanto, prolongar o tempo de operação nos reservatórios já existentes se tornou uma boa alternativa para atender a demanda de óleo e controlar as adversidades geradas pelas operações de baixa eficiência. Para isso, a técnica de controle de conformidade vem sendo muito discutida no intuito de melhorar a eficiência de varrido e diminuir a água de produção indesejada. Dentre os métodos químicos existentes, os géis poliméricos exibem a capacidade de bloquear as regiões fraturadas ou heterogêneas presentes em reservatórios com problemas de permeabilidade. No entanto, a autonomia destes hidrogéis ainda não foi completamente estabelecida por conta das drásticas condições encontradas nesses reservatórios. Neste contexto, agentes de reforço vêm sendo utilizados para a elaboração de hidrogéis poliméricos compósitos, os quais buscam melhorar as propriedades frente aos sistemas convencionais. Dentre os sistemas de reforço estão: nanosílica, argila, nanotubos de carbono, cinzas volantes de carvão, partículas de asfaltenos, nanocristais de celulose, óxido de grafeno, dentre outras. No geral, a presença destes componentes contribui de maneira semelhante, portanto deve-se considerar o custo e, principalmente, o uso de materiais ecológicos não prejudiciais ao meio-ambiente.