Synthesis of silica/metatitanic acid nanocomposite and evaluation of its catalytic performance for aquathermolysis reaction of extra-heavy crude oil

A lipophilic silica/metatitantic acid (denoted as SiO2/H2TiO3) nanocomposite was synthesized by hydrothermal reaction with surface-modified SiO2 as the lipophilic carrier. As-synthesized SiO2/H2TiO3 nanocomposite was used as a catalyst to promote the aquathermolysis reaction of extra-heavy crude oil thereby facilitating the recovering from the deep reservoirs at lowered temperature. The catalytic performance of the as-synthesized SiO2/H2TiO3 catalyst for the aquathermolysis reaction of the heavy oil at a moderate temperature of 150 °C was evaluated in relation to the structural characterizations by TEM, FTIR, XRD and FESEM as well as the determination of the specific surface area by N2 adsorption–desorption method. Findings indicate that as-synthesized SiO2/H2TiO3 nanocomposite exhibits an average size of about 20 nm as well as good lipophilicity and dispersibility in various organic solvents; and it shows good catalytic performance for the aquathermolysis reaction of the extra-heavy oil extracted from Shengli Oilfield of China. Namely, the as-synthesized SiO2/H2TiO3 catalyst is capable of significantly reducing the viscosity of the tested heavy oil from 58,000 cP to 16,000 cP (referring to a viscosity reduction rate of 72.41%) at a mass fraction of 0.5%, a reaction temperature of 150 °C and a reaction time of 36 h, showing potential application in downhole upgrading heavy crude oils.

The organic groups of surface modified SiO2 provide the lipophilicity of SiO2/H2TiO3 during the synthesis. So the SiO2/H2TiO3 can disperse into heavy crude oil and improve the catalytic efficiency. Figure optionsDownload as PowerPoint slide