| dc.description.abstract | Experimental and analytical studies have been carried out to better understand the effects of additives on viscosity, density and surface tension of intermediate and heavy crude oils. The studies have been conducted for the following oil samples: San Francisco oil from Columbia with specific gravity of 28o-29o API, Duri oil with gravity of 19o-21o API, Jobo oil with gravity of 8o-9o API and San Ardo oil gravity of 11o-13o API. The additive used in all of the experiments is petroleum distillate. The experiments consist of using petroleum distillate as an additive for different samples of heavy crude oils. The experiments include making a mixture by adding petroleum distillate to oil samples and measuring surface tension, viscosity and density of pure oil samples and mixtures at different temperatures. The petroleum distillate/oil ratios are the following ratios: 1:100, 2:100, 3:100, 4:100 and 5:100.
Experimental results showed that use of petroleum distillate as an additive increases API gravity and leads to reduction in viscosity and surface tension for all the samples. Results showed for all petroleum distillate/oil ratios viscosity and interfacial tension decreases with temperature. As petroleum distillate/oil ratio increases, oil viscosity and surface tension decrease more significantly at lower temperatures than at higher temperatures. After all experiments were completed an analytical correlation was done based on the experiment results to develop “mixing rules”. Using this correlation viscosity, density and surface tension of different petroleum distillate/oil mixtures were obtained (output).These had properties of pure oil and petroleum distillate, mixture ratios and temperatures at which measurement is supposed to be done (output). Using this correlation a good match was achieved. For all of the cases (viscosity, density and surface tension), correlation coefficient (R²) was more than 0.9 which proved to be optimum for a really good match. | en |
