High temperatures and wellbore-integrity issues are often encountered when drilling onshore and offshore wells. Formate drilling fluid was initially developed in the 1990s to battle high temperature. Field applications of formate mud have increased since the 2000s. This paper presents worldwide implementations of formate drilling fluid, including field cases in Canada, the North Sea, Germany, the Middle East, and Russia. Experiences with formate mud in Chinese fields that were previously unknown because of the language barrier are also reported. Most field cases reported high rate of penetration (ROP), excellent wellbore stability, good thermal stability, and high production rates upon completion. Reclamation and reuse of formate have significantly improved the cost–effectiveness of formate mud. In the current drilling industry, formate fluid has become one of the best choices for battling high–temperature and wellbore–stability issues.