Lost circulation control during drilling and completion in complex formations

Well drilling is a common method for Earth exploration, underground mineral resource extraction, and geological storage of nuclear waste and carbon dioxide. Drilling fluid circulates in the well during drilling, cooling the drill bit, transporting rock cuttings, preventing wellbore collapse, and balancing formation pressure. Lost circulation occurs when less fluid returns from the wellbore than is pumped into it, resulting in economic losses due to drilling fluid wastage and nonproductive time. Untreated losses can cause well control issues, poor hole cleaning, pack-offs, and stuck pipe, impairing normal drilling. Lost circulation incidents are more likely to occur with the increasing share of difficult wells (deep-water, deviated, horizontal, high pressure, high temperature) in the drilling portfolio. It is one of the most troublesome drilling problems. . . .