A well completion and workover method wherein a subterranean formation is contacted with a high density, nondamaging treating fluid which comprises a saturated, aqueous saline solution with at least one water soluble salt that is substantially insoluble in the saturated saline solution. The water soluble salt has a particle size range of about 5 microns to about 800 microns, and greater than about 5 percent of the particles are coarser than 44 microns to control the pressure in the formation; to bridge and seal off the formation; to avoid particle invasion; and also to minimize fluid loss to the formation. A minor amount of a fluid loss additive is included in the treating fluid to inhibit loss of fluid into the formation and a minor amount of a suspension additive is included in the treating fluid to prevent settling of the water soluble salt particles in the aqueous saline solution. The aqueous saline solution should have a density of at least about 10 pounds per gallon.