Simulation of Asphaltene precipitation and Deposition Effects on reservoir production performance, a case study

In this Paper, effects of Asphaltene precipitation and deposition in one of Iranian heavy oil reservoirs have been studied. after building a full field geological model using structural and petrophysical data a sector has been extracted around 2 active well in this field and used in future reservoir performance predictions. Asphaltene content of the fluid of this reservoir was measured using IP-143 test to be approximately 24.1 %.thermodynamic modeling of the fluid of this reservoir including precipitating component (Asphaltene) was performed using Ping-Robinson Equation of state and solid model which is based on fugacity of the phases was used to predict Asphaltene deposition envelope. An 8 component model assumed to be enough to predict exactly the reservoir fluid behavior and Asphaltene precipitation and deposition in reservoir performance prediction. An EOS based compositional reservoir simulator was used to predict asphaltene deposition effect on reservoir performance. this simulator has been designed to simulate nearly all asphaltene deposition mechanisms including surface adsorption, mechanical entrapment and reentrainment of solid phase. Effect of drilling horizontal wells on reservoir production also has been analyzes. The results of these studies show that asphaltene precipitation and deposition by insitu upgrading of the reservoir oil and reducing its viscosity can improve oil recovery factor and production rate. It must be pointed out that due to geological condition a dual porosity model has been taken for reservoir simulation.