Steamflooding of heavy and especially light oil reservoirs involves steam distillation of reservoir fluids. Accurate description of the steam distillation behavior of the reservoir oil is required in evaluation of reservoirs for steamflood potential and in the numerical modeling of reservoir performance using compositional simulators. The present work describes an experimental investigation into the effect of heat and water on the properties of crude oils with emphasis on compositional changes important for steamflooding.
Four crude oils in the gravity range (13 – 33° API) have been studied by steam distillation, coreflooding, gas chromatography, and actual distillation by ASTM D-2892. Some of the products from these experiments have been further characterized by a pseudo compositional analysis, densities, and molecular weight. Extensive compositional analyses on these effluents provide an insight toward understanding the steam distillation process.
Laboratory simulated distillation closely agreed with the total boiling point measured by ASTM D-2892. Boiling fractions collected from the TBP analysis were further characterized by composition (simulated distillation) and molecular weight.
Compositional analysis of laboratory coreflood effluents in a light oil (33° API) steamflood suggests preferential efficient recovery of light and middle boiling fractions.