Nanocomposite gels for water shut-off and temporary plugging in the petroleum industry: a review

Compared with conventional polymer gels, nanocomposite gels have significant advantages in strength and temperature resistance. They can adapt to more severe reservoir environments and achieve the purpose of controlling water and increasing oil or temporarily plugging and diverting. Based on nanoparticles used in nanocomposite gels, nanocomposite gels can be divided into silica-based nanocomposite gels, nano-montmorillonite-based nanocomposite gels, layered silicate nanocomposite gels, laponite-based nanocomposite gels, CFA (coal fly ash)-based nanocomposite gels, and other nanocomposite gels. The researcher summarized the materials used in various nanocomposite gels (nanomaterials, main polymers, and crosslinking agents), mechanisms, excellent performance, and analyzed the shortcomings of various nanocomposite gels and current development trends. The results show that the research of nanocomposite gels needs to deal with the high temperature and high salinity oil and gas reservoir environment, and it is necessary to adopt environmentally friendly, easy-to-prepare and cheap materials. At the same time, more numerical simulation studies are needed for theoretical guidance.