Increase in the Oil Recovery Factor through the Injection of Nano-Chemicals Dispersed in Gas

Tight reservoirs have different challenges, among them, there are several related to the low permeability of the rock and diverse damage mechanisms. Conventional Chemical Injection in these types of reservoirs has some disadvantages such as shallow penetration and the use of high volumes of chemicals. Therefore, new technologies such as chemical dispersion on a gas flow have been developed to achieve deeper penetration of the chemicals and mitigate formation damage in gas- condensate tight reservoirs by mobilizing condensate banks. However, the inclusion of nanoparticles in the dispersed phase for EOR processes is a novelty. Since silica nanoparticles reduce interfacial tension and alter the wettability of the rock, the objective of this study is to evaluate the effect of adding silica nanoparticles (S1) dispersed in two treatments (A and B) at a dosage of (10-100 mg·L−1) on wettability, interfacial tension, emulsion stability, and rock treatment adsorption. To compare them with a silica-based nanofluid, treatment C was also evaluated. The dosage selection of silica nanoparticles was made through static tests such as interfacial tension, contact angle, and static formation of emulsions. The best nanofluid among the ones prepared from treatments A and B was evaluated in dynamic tests to be compared with treatment C through the capillary blockage, oil recovery, and oil recovery in the perdurability scenario tests. Treatments A and C experienced a great affinity for the rock in the adsorption isotherms, while treatment B had less affinity for the rock. The addition of nanoparticles (S1) to treatments A and B at a concentration of 50 and 10 mg·L−1 respectively, led to an interfacial tension reduction of 16% and 40%, each one; and a respective water contact angle reduction of 17% and 2%. Furthermore, the addition of nanoparticles S1 promoted less stable emulsions, which is favorable for these processes. Finally, 26% of the additional increase in oil recovery and a greater perdurability was obtained with treatment B + 10 ppm Nps S1 in core displacement tests.