METHOD FOR PLACEMENT OF A SCALE INHIBITOR IN A FORMATION

摘要

A method for placement of a long life scale inhibitor into a formation where variable density scale inhibitors are utilized. A substantially low density non-reactive fluid is loaded into an interval of the formation to be treated. Afterwards, a high density first stage scale inhibitor is injected into the interval. Thereafter, a low density spacer fluid is injected into the interval being treated. Next, a second stage high density scale inhibitor having a density lower than the first stage inhibitor is injected into said interval. Subsequently, a low density spacer is injected into the interval. Volume increments are repeatedly injected with decreasing fluid densities until a desired zone has been treated. The entire treatment is then overflushed with an inert high density fluid. Use of this method allows even inhibitor distribution in intervals of a formation with permeability variations thereby preventing scale build-up.