| 摘要 |
A method for simultaneously matrix acidizing two spaced apart zones of a carbonate containing formation. Initially, a lower density acid is injected into an upper zone of said formation hereby forming wormholes which make this zone more permeable. Simultaneous with the injection of the lower density acid, a higher density acid is injected into a lower spaced apart zone of said formation at a pressure sufficient to simultaneously form wormholes within said lower zone thereby acidizing each zone simultaneously. Thereafter, a solidifiable viscous gel with gel breakers is directed into the upper and lower zones which gel enters the wormholes and forms a solid gel therein which precludes entry of additional acid while displacing the acid further into the formation. Subsequently, additional acid is introduced into the upper and lower zones which acid bypasses the wormholes containing the solid gel and penetrates substantially further thereby substantially increasing the permeability of the formation.
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