Study of CO2 effect on asphaltene precipitation and compositional simulation of asphaltenic oil reservoir

Abstract

A model which is based on Flory-Huggins polymer-solution theory and Hildebrand solubility concept has been developed which shows an excellent match with experimental data. The fine-tuned model is then possible to predict weight percent of precipitated asphaltene at wide range of conditions (changes in pressure, temperature and composition). The prediction can be used to identify at which conditions lead to precipitation of asphaltene. The procedure of calculation is quite simple compared to any other models which involve many requirements of parameters which most of them are difficult to estimate (complicated). A compositional simulation is performed using a simple reservoir model to study effect of dynamic conditions to asphaltene behavior. The main objective of simulation is to investigate temperature effect during CO2 flooding. It has been reported that temperature can have reverse effect from the normal convention. Comparison performance between CO2 and water flooding are also simulated. Quantification of asphaltene deposition and permeability reduction are carried out to give a clear picture on “how much” asphaltene deposits and “when” deposition of asphaltene is more pronounced.