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One of the major problems in heavy oil recovery in Mexican carbonate reservoirs is related to the formation of highly stable and viscous water-in-oil emulsions, which impacts on decreasing in hydrocarbon production. This fact is derived from the presence of high amounts of asphaltenes in the oil, as well as from the high concentrations of divalent ions in the formation water. In order to develop a technological solution for this problem, in this work a theoretical/experimental methodology is presented, which allows the development of new surfactants with multifunctional capabilities, such as changes in rock wettability, interfacial tension and emulsion breaking up. The molecular modeling is used to study emulsions formation, as well as the demulsifying capability of two kinds of surfactants: branched geminal zwitterionic liquids and new zwitterionic macrocyclic oxo-aza-crown ethers. Spontaneous-imbibition studies were carried out in order to determine the capacity of these surfactants to increase the oil recovery factor. Both theoretical and experimental parts show that the new macrocyclic surfactants presented a better performance than the branched germinal zwitterionic surfactants, therefore, they constitute a potential technological solution to increase oil recovery factor in the mentioned reservoirs. Their emulsion breaking up capacity, allows to extract oil from the porous media and avoids formation of new emulsions in the extraction process.

Theoretically, were designed and optimized by Density Functional Theory (DFT), the itaconic acid (IA), sodium vinyl sulphonate (VS) and aconitic acid (AA) singles molecules. Also, its corresponding interactions as pairs IA-VS, IA-AA and VS-AA for a better comprehension of constituents in the molecular design of the new terpolymer (labeled as PIAVSAA). Besides, the mineral scales calcium carbonate (CaCO3) and calcium sulfate (CaSO4) also were designed by computational chemistry. Attributable to the energy values obtained, PIAVSAA terpolymer promise an efficient capture of calcium ions of the scale phase better than commercial chemicals derived from acrylic acid. Experimentally, and to evaluate the anti-scale activity, were carried tests that demonstrate the capability of the new PIAVSAA to control inorganic scales problems that may become an impediment to production and avoid the plugging of the production tubing, assuring oil production.

Oil-in-water (O/W) emulsions are an innovate manner by which otherwise highly viscous heavy and extra-heavy crude oils can be transported from producing sites to transforming sites through pipelines. In spite of the important reduction in viscosity and pressure drops, water must be removed from the crude oil before further process or refining. Hence, the present study discusses the demulsification of an O/W emulsion prepared with Mexican heavy crude oil. A comparative study was carried out between microwave and oil bath heating with regard to water separation time. The effect of a chemical demulsifier and salt content of the O/W emulsion’s aqueous phase was also investigated. Microwave dielectric heating of O/W emulsions showed a greater degree of water separation in less time than conventional oil bath heating. Water separation of O/W emulsions increased with microwave power and salt content of the aqueous phase, and in the presence of a chemical demulsifier. Finally, the fluorescence emission spectra of the initial and treated O/W emulsions were in agreement with the water separation results and provide a quick and effective way to study the demulsification processes.

Alkyl-O-glucoside and -cellobioside biosurfactants were synthesized with a long fatty chain (C 8 –C 18 ) in order to prepare stable and low viscous oil-in-water (O/W) emulsions of a Mexican heavy crude oil. The resulting O/W emulsions, prepared with a single alkyl-O-glucoside or alkyl-O-cellobioside, were very unstable and broke out. Only the use of tetradecyl-O-cellobioside allowed the formation of a poor stable complex emulsion with the broader particle size distribution and more viscous than other emulsions. Nonetheless, we observed a synergistic effect when a biosurfactant mixture was used and the resulting emulsions were stable for several days while water separation occurred constantly within 40 days in static conditions. The mixture of biosurfactants with a pC 20 value higher than 4.0 and a CMC/C 20 ratio higher than 1.0 favored the formation of a less viscous, narrow particle size distribution and thermal stable O/W emulsion. This feature is remarkable important when we look for the pipeline transportation of heavy and extra-heavy crude oils as O/W emulsions. In this work, we present the characterization of biosurfactants as well as the formulation and properties of O/W emulsions of a Mexican heavy crude oil.