Abstract: A method and wellbore fluid using Curaua fiber to prevent or cure loss circulation during well operations. The wellbore fluid includes a base fluid and a plurality of Curaua fibers. The wellbore fluid may include concentration up to 120 lb/bbl Curaua fibers. The base fluid may include at least one of water-based fluid, brine-based fluid, oil-based fluid, synthetic-based fluid, or Pneumatic-drilling fluid system. The water-based fluids may further include at least one of seawater, brine, saturated brine, or formate brine. The water-based fluid may include a dispersed system. The water-based fluid may further include a non-dispersed system. The oil-based fluid may include at least one of diesel, mineral oil, and low-toxicity linear olefins and paraffins. The synthetic-based fluid may include at least one of one of esters, internal olefins and linear paraffins. The oil-based and the synthetic-based fluids may further include lime.