摘要 |
A process for acidizing a formation where variable density acids 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 acid is injected into the interval. Thereafter, a low density spacer fluid is injected into the interval being treated. Next, a second stage high density acid having a density lower than the first stage acid 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.
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