A method of forming a subterranean well and a method of reducing lost circulation in a subterranean well while drilling the subterranean well are disclosed. The methods include using multi-component fibers as lost-circulation materials. The multi-component fibers having external surfaces and include at least a first polymeric composition and a second polymeric composition. At least a portion of the external surfaces of the multi-component fibers includes the first polymeric composition, which at least partially adhesively bonds the mud cake formed during the method.