This invention relates to the optimum formulation of workover and completion fluids used in oil, gas, water, or mineral recovery wells. Specifically, it discloses a method of processing peanut hulls and combining these with a suitable suspending agent in order to effect a seal against permeable formations during workover, completion, coring, drill-stem-testing, or drilling operations, without causing permanent permeability damage. Moreover, it discloses that when the procedures discovered are practiced as taught by this invention, the sealing action is reversible by simple fluid circulation and placing the well on production.
