Transcripción del resumen del autor. The alteration of the wettability from liquid-wetting to intermediate gas-wetting has great potential in improving gas well productivity, from mitigating water blocking to condensate banking in gas reservoirs. Even a small quantity of salt ions (such as Na+) in the initial saturation in rock has a detrimental effect on the alteration of the wettability by chemical treatments. The initial salt ions may cause clay release and permeability reduction. Berea cores are usually used in laboratory flow studies, including wettability alterations. In this work, we present a comprehensive study on the use of Berea, both unfired and fired, in single- and two-phase flows, with a focus on the salt and firing effect on the chemical treatment. Three fluoropolymeric surfactants are used. We find that one of the three, a nonionic surfactant, is effective in the alteration of wettability in the fired Berea (with and without salt in the initial saturation). The treatment efficiency of ionic surfactants is reduced in the presence of the initial salt.

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