Nanoparticles based drilling muds a solution to drill elevated temperature wells: A review

Demand of the oil and gas energy is increasing very drastically. Conventional hydrocarbon reservoirs contain below the sealing cap rock (shale) and easily move towards wellbore are at the depletion stage. Therefore, drilling engineers in collaboration with mud engineers, geologists and geophysicists are looking for innovative materials to drill unconventional hydrocarbons reservoir which are distributed at the basin scale and cannot approach easily. Geo-thermal energy wells and most of unconventional reservoirs are occurred at high pressure high temperature (HPHT) conditions. Conventional micro-macro organic drilling mud additives with heat insulator in nature can minimize efficiency while drilling HPHT wells. Oil-based muds (OBM) are strictly restricted due to high toxic level and poor emulsion stability at HT. However, this review suggests that addition of macro size organic particles and inorganic nanoparticles can enhance rheological performance, reduce filtrate loss volume and improve shale inhibition characteristics of environmental friendly water-based mud (WBM). Despite an impressive amount of experimental work has been done over drilling additives and their effect over rheological and shale inhibition, taking into account their literature review are rare. In addition, there is no review work of the knowledge gained to date. This work will hope fully trigger further development and new research topics in the area of drilling muds system.