During the early 21st century, nanotechnology has stood strong in the oil and gas industry, with many applications that have gone from laboratory and numerical simulation studies to successful trial applications in the field. In this Review, recent advances of nanofluid and nanoparticle applications in real environments of the oil and gas industry are presented. These applications cover more than 20 wells in Colombia that have been treated to overcome different formation damage mechanisms, such as asphaltene precipitation/deposition, fines migration, and inorganic scale deposition. Also, different approaches to enhance drilling fluids in Canada, Brazil, Iran, and Colombia are examined. In the case of improved oil recovery (IOR), different applications are discussed, including strategies to improve the productivity of heavy crude oil and extra-heavy crude oil reservoirs through enhanced mobility and hydraulic fracturing in Colombia, a field trial for water shutoff in Csongrad-3 formation in the Algyo field in Hungary, nanocapsules injection for wettability alteration, applications of gas injection (N2 and CO2) in the presence of nanoparticles in Austin chalk, Buda and Eagle Ford formations in the United States, and the use of nanoparticle-assisted foams for well dewatering in China. For secondary and tertiary recovery, we explore the design and implementation of A-Dots and carbon quantum dots as tracers in Saudi Arabia and Colombia, respectively, hydrophobic nanoparticles as drag reducers in injector wells in China, and nanofluids for enhancing chemical enhanced oil recovery processes in southern Colombia. It is worth mentioning that the results were based on oil production and reserves derived from production curves and analysis of the declination curves. Finally, challenges and perspectives of the role of nanotechnology in the oil and gas industry today are discussed.