This chapter reviews active research efforts have been made on the possible use of nanoscale catalysts for the upgrading of heavy and extra-heavy oil, in-situ in the reservoir. It discusses the persistent development and field trials of the combined technology of horizontal well and hydraulic fracturing brought the amazing shale oil and gas production in the US and Canada, which for many decades was considered to be impossible to achieve. All around the world and especially in Alberta, Canada, and the Orinoco Belt of Venezuela, there are trillions of barrels of heavy oil to be recovered if the economics of their production is right. There exists a huge literature on steam-assisted gravity drainage, cyclic steam stimulation (CSS), and other steam-based heavy oil recovery techniques, for which there are excellent reviews and monographs. Yi et al. studied the effects of adding nickel nanoparticles on oil recovery during the late cycles of CSS process.