A method for evaluating the kinetics of n-heptane-induced asphaltene precipitation from various Saskatchewan crude oils during light hydrocarbon flooding

A molar n-heptane programmed titration technique has been developed for evaluating the kinetics of n-heptane-induced asphaltene precipitation from three Saskatchewan crude oils during light hydrocarbon flooding. Results from the technique show that asphaltene precipitation kinetics can be modeled semi quantitatively in terms of a power law rate model. Values for the reaction order for n-heptane (35.8-43.3) were much larger than those for asphaltene (1.0-2.5) showing that asphaltene precipitation is more sensitive to the n-heptane added than the asphaltene content of the oil. Also, the large activation energies obtained (32-185 kJ/mol) confirms experimentally that n-heptane asphaltene precipitation is not just a mere physical process.