Modeling and Optimization of Asphaltene Deposition in Porous Media Using Genetic Algorithm Technique

Abstract

Different models have been proposed for deposition of asphaltene on reservoir rocks that due to complexity of asphaltene nature, most of them have not been productive. Here, a reliable model is proposed which despite of previous models, considers the change in asphaltene saturation in the core. The obtained experimental data in the laboratory was used for model validation. In this work, a series of core flooding tests was carried out in presence of connate water at different solvent-oil volume ratios. Pressure drop was measured at three different terminals along the core. The obtained experimental data as well as mass balance equations, momentum equation, asphaltene deposition and permeability reduction models were employed in an iterative scheme to simulate the deposition process. Genetic algorithm (GA), which is a powerful tool, was applied for history matching, optimization and determination of the model parameters. Well match observed between the model results and experimental data confirms the accuracy of the proposed mathematical model of asphaltene deposition in porous media. Also, applied improvement on the model resulted in accurate simulation as well as determination of precipitated asphaltene saturation. Optimization shows that all deposition mechanisms, surface deposition, entrainment and pore plugging, are dominant during the permeability evolution process. Results of this work can be helpful for reliable simulation of the dynamic asphaltene deposition process during different production schemes.

Asphaltene Formation Damage Stimulation by Ultrasound: An Analytical Approach Using Bundle of Tubes Modeling

“…While the interstitial velocity is low because of the little value of flow rate (about 1 mL/min), is approximately set equal to 0 , that is, equal to 1. Figure 11 presents the results of modeling in comparison to the experimental results of Hematfar et al [16]. The results of modeling are in reasonable agreement with the experiments.…”

“…Based on (16), in order to find the total surface of asphaltene particles, total number of particles should be specified. In this regard, by considering that the volumetric summation of all particles represents the asphaltene volumetric content in the section, the total number of asphaltene particles can be calculated from following equation:…”

“…Hematfar et al [16] presented experimental results of permeability reduction due to the asphaltene deposition during coinjection of alkane and oil in reservoir rock samples. Fortunately, the PSD of asphaltene versus flocculation time for this oil sample is available [11].…”

“…Fortunately, the PSD of asphaltene versus flocculation time for this oil sample is available [11]. The input data of current asphaltene deposition modeling is obtained from combination of results of Hematfar et al [16] and Najafi et al [11]. The properties of rock and fluid are provided in Tables 1 and 2.…”