Foam-Acid Treatment of Formations


The foam-acid treatment of formation is done by injection of aerated or gassed acid solution into it. To stabilize the foam system the acid solution is treated with surface-active substance.

In contrast to acid solution, which in connection with carbonate rock reacts quickly in the borehole critical area and is fully neutralized, the foam-acid neutralizes very slowly and it is possible to influence upon remote zones of treatment.

The main advantage of the foam-acid treatment in comparisson with treatment by acid solution is its ability to increase repeatedly the scope of the treated formation on account of penetration selectivity of the foam-acid into crevices with different permeability.

Besides, the high resilient energy of the aerated solution makes it possible to remove effectivelly products of reaction from the formation.