RHEOLOGICAL PROPERTIES OF MICELLAR SOLUTIONS OF A MIXTURE OF COCAMIDOPROPYLBETAINE AND SULFOSUCCINATES OF ETOXYLATED FATTY ALCOHOLS

Abstract

Restoring and improving the filtration characteristics of the bottomhole zone of carbonate reservoirs using acidic compositions is the most com- monly used geological and technical measure. One of the main recent trends to increase the effectiveness of acidic compositions is the modifi- cation of their compositions, which is associated with the addition of various organic and inorganic components in order to give the reagent the required technological properties. An example of the acidic composi- tions modification is the use of viscoelastic viscoelastic surfactants, which give acidic reagents «self-diverting» properties. When hydrochlo- ric acid interacts with carbonate rock, a change in the pH of the medium changes and divalent metal cations concentration increase, which leads to a thickening of the system and the deviation of a fresh acid portion, moreover viscoelastic properties are not manifested in the presence of hydrocarbons. Thus, it is a continuous diverting process during the acid composition injection. The change in the rheological properties of the composition is explained by the aggregation of surfactants with the for- mation of a three-dimensional micellar structure with viscoelastic char- acteristics. This paper presents the results of laboratory experiments of the rheo- logical properties of aqueous and hydrochloric acid solutions of the mixture of cocamidopropylbetaine and sulfosuccinates etoxylated fatty alcohol sulfosuccinates. The rheological properties study results of mixed micellar aqueous and hydrochloric acid solutions based on the optimal ratio of surfactant, the dependence of the viscosity of mixed zwitterionic-anionic surfactant solutions on the total concentration and the viscosity dependence of the composition on reactions with carbonate rock, also the temperature and hydrocarbons effect on the rheological properties of a viscoelastic surfactant system indicate that the proposed surfactants combination enables to develop acid composition which has viscoelastic gel properties.