During the development of a secondary recovery project by water injection in a Colombian field called Casabe it was observed that the packed production wells presented an abnormal declination on production rates. This was initially attributed to the completion type: slotted liners or screen packed with 10/20 or 20/40 gravel. The packings have an average length of 1,200 ft. The partial recovery of a slotted liner and screen demonstrated that there was an impermeable material that plugging the external phase of the pipe by 90%, not allowing the oil to flow into the wells. The phenomena in question seriously compromised the volumes of production and the life span of the injection project since plugging in the wells generates loss of productivity and represuring in the field causing premature casing collapse. This article shows the methodology used by teamwork in charge of defining the cause for the plugging in the wells, designing a treatment that would lessen the problem and establishing an operational technique to selectively stimulate the intervals present in the packed wells.