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Amir H. Mohammadi - One of the best experts on this subject based on the ideXlab platform.

  • determination of Minimum Miscibility Pressure in n2 crude oil system a robust compositional model
    Fuel, 2016
    Co-Authors: Abdolhossein Hemmatisarapardeh, Amir H. Mohammadi, Mohammad Fathinasab, Erfan Mohagheghian
    Abstract:

    Nitrogen has been valued as an economical alternative injection gas for gas-based enhanced oil recovery (EOR) processes. Minimum Miscibility Pressure (MMP) is the most important parameter to successfully design N2 flooding. In this communication, a data bank covering wide ranges of thermodynamic and compositional conditions was gathered from open literature. Afterward, a rigorous approach, namely least square support vector machine (LSSVM) optimized with coupled simulated annealing (CSA) was proposed to develop a reliable and robust model for the prediction of MMP of pure/impure N2–crude oil. The results of this study showed that the proposed model is more reliable and accurate than the pre-existing models in a wider range of thermodynamic and process conditions. The proposed model predicts the total dataset (84 MMP data points of pure N2, nitrogen mixture streams and lean gases) with an average absolute relative error of 5.17%. Finally, by employing the relevancy factor, it was found that the intermediate components of crude oil have the most significant impact on the nitrogen MMP estimation and Leverage approach shows that only two data points (2.4%) are outside the applicability domain of the model proving the reliability of the developed model.

  • intelligent model for prediction of co2 reservoir oil Minimum Miscibility Pressure
    Fuel, 2013
    Co-Authors: Amin Shokrollahi, Milad Arabloo, Farhad Gharagheizi, Amir H. Mohammadi
    Abstract:

    Multiple contact miscible floods such as injection of relatively inexpensive gases into oil reservoirs are considered as well-established enhanced oil recovery (EOR) techniques for conventional reservoirs. A fundamental factor in the design of gas injection project is the Minimum Miscibility Pressure (MMP), whereas local sweep efficiency from gas injection is very much dependent on the MMP. Slim tube displacements, and rising bubble apparatus (RBA) are two main tests that are used for experimentally determination of MMP but these tests are both costly and time consuming. Hence, searching for quick and accurate mathematical determination of gas–oil MMP is inevitable. The objective of this study is to present a reliable, and predictive model namely, Least-Squares Support Vector Machine (LSSVM) to predict pure and impure CO2 MMP. To this end, about 147 data sets belonging to experimental CO2 MMP values from the literature and corresponding gas/oil compositional information was used to construct and evaluate the reliability of the model. The results show that the proposed model significantly outperforms all the existing methods and provide predictions in acceptable agreement with experimental data. Moreover, it is shown that the proposed model is capable of simulating the actual physical trend of CO2 MMP versus five most important input parameters: reservoir temperature, molecular weight of pentane plus, hydrogen sulfide and nitrogen concentration. Finally, for detection of the probable doubtful CO2 MMP data, outlier diagnosis was performed on the data sets.

  • prediction of Minimum Miscibility Pressure in oil reservoirs using a modified saft equation of state
    Fuel, 2013
    Co-Authors: Alireza Fazlali, Mohammad Nikookar, Alireza Aghaaminiha, Amir H. Mohammadi
    Abstract:

    Abstract In a miscible gas flooding to heavy oil reservoirs, multiple-contact Miscibility between injected gas and reservoir oil can be achieved at Pressure greater than a Minimum value that is referred to Minimum Miscibility Pressure (MMP). This research includes two parts: first, modification of simplified SAFT ( m SSAFT) equation of state is derived to describe vapor-liquid equilibrium calculations and second, prediction of MMP according to forward multiple contact model is done. With respect to objective function, adjustable parameters of SSAFT and m SSAFT were obtained for 21 pure compounds. Comparison of AAD% of the results of m SSAFT, SSAFT and PR EOSs in predicting vapor Pressure, liquid density and enthalpy shows that m SSAFT is the most accurate of all. Also, accuracy of these three EOSs for various mixtures has been verified, and the results confirm the reliability of m SSAFT EOS. At last, AAD% of MMP prediction by mentioned EOSs ( m SSAFT is 2.20%, SSAFT is 3.25% and PR is 4.13%) proves that Statistical EOSs are more reliable than cubic EOS in modeling MMP.

  • Computational procedure for determination of Minimum Miscibility Pressure of reservoir oil
    Fuel, 2013
    Co-Authors: Alireza Fazlali, Mohammad Nikookar, Amir H. Mohammadi
    Abstract:

    Abstract A methodology has been developed for computing Minimum Miscibility Pressure (MMP) for the displacement of oil by multi-component gas injection (It is focused on multiple contact Miscibility mechanism (forward/backward)). The algorithm is presented for the calculation of the Minimum Miscibility Pressure using an equation of state. The Peng–Robinson (PR) equation of state (EoS) along with random mixing rules is used to determine phase behavior of oil and gas. The key assumption of the method is that the MMP is completely independent of the porous media. This algorithm handles vaporizing (forward multiple contact) Miscibility mechanisms. The MMP calculations include Pressure/temperature flash calculations and oil properties characterization method of Riazi–Daubert. The proposed algorithm is fast and easy to compute.

  • Intelligent model for prediction of CO2 – Reservoir oil Minimum Miscibility Pressure
    Fuel, 2013
    Co-Authors: Amin Shokrollahi, Milad Arabloo, Farhad Gharagheizi, Amir H. Mohammadi
    Abstract:

    Abstract Multiple contact miscible floods such as injection of relatively inexpensive gases into oil reservoirs are considered as well-established enhanced oil recovery (EOR) techniques for conventional reservoirs. A fundamental factor in the design of gas injection project is the Minimum Miscibility Pressure (MMP), whereas local sweep efficiency from gas injection is very much dependent on the MMP. Slim tube displacements, and rising bubble apparatus (RBA) are two main tests that are used for experimentally determination of MMP but these tests are both costly and time consuming. Hence, searching for quick and accurate mathematical determination of gas–oil MMP is inevitable. The objective of this study is to present a reliable, and predictive model namely, Least-Squares Support Vector Machine (LSSVM) to predict pure and impure CO2 MMP. To this end, about 147 data sets belonging to experimental CO2 MMP values from the literature and corresponding gas/oil compositional information was used to construct and evaluate the reliability of the model. The results show that the proposed model significantly outperforms all the existing methods and provide predictions in acceptable agreement with experimental data. Moreover, it is shown that the proposed model is capable of simulating the actual physical trend of CO2 MMP versus five most important input parameters: reservoir temperature, molecular weight of pentane plus, hydrogen sulfide and nitrogen concentration. Finally, for detection of the probable doubtful CO2 MMP data, outlier diagnosis was performed on the data sets.

Asghar Gandomkar - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Investigation of Asphaltene Content Effect on Crude Oil/CO2 Minimum Miscibility Pressure
    Periodica Polytechnica Chemical Engineering, 2020
    Co-Authors: Mehdi Ghorbani, Asghar Gandomkar, Gholamhosein Montazeri, Bizhan Honarvar, Amin Azdarpour, Mohammad Rezaee
    Abstract:

    Minimum Miscibility Pressure (MMP) is regarded as one of the foremost parameters required to be measured in a CO2 injection process. Therefore, a reasonable approximation of the MMP can be useful for better development of injection conditions as well as planning surface facilities. In this study, the impact of asphaltene content ranging from 3.84 % to 16 % on CO2/heavy oil MMP is evaluated. In this respect, slim tube Miscibility and Vanishing Interfacial Tension (VIT) tests are used. Regarding the VIT test, the Interfacial Tension (IFT) is measured by means of two methods including pendant drop and capillary apparatuses, and thereafter the MMP measurement error between slim tube and VIT methods are calculated. Based on the results, by increasing the asphaltene content, the measured MMP by slim tube method increases linearly while that by VIT follows no clear trend. The results also indicate that there is an asphaltene content range within which the MMP error between slim tube and VIT tests is minimized. IFT measurement by pendant drop and Capillary Glass Tube (CGT) methods show that by increasing asphaltene content up to 10.15 %, IFT declines, whereas for further increase in content, IFT increases because of the irregular dispersion of asphaltene in oil droplets.

  • modified vanishing interfacial tension vit test for co2 oil Minimum Miscibility Pressure mmp measurement
    Journal of Natural Gas Science and Engineering, 2014
    Co-Authors: Mehdi Ghorbani, Ali Momeni, Saied Safavi, Asghar Gandomkar
    Abstract:

    Abstract Miscible gas injection is one of the most popular and applicable enhanced oil recovery method in oil fields. Minimum Miscibility Pressure (MMP) is an important parameter for an enhanced oil recovery process involving carbon dioxide or hydrocarbon miscible gas injection. There are many methods for measuring MMP but the most standard method for measuring MMP value in oil field gas injection process is slim tube method, which is very time consuming (4–6 weeks). Measurements of the interfacial tension of mixtures of a reservoir fluid and injection gas at various Pressures have been proposed recently as an experimental method for predicting the Minimum Miscibility Pressure (MMP) in an experiment called the vanishing interfacial tension (VIT) technique. This method is quantitative in nature and fast (2–3 days) with respect to slim tube method. VIT technique is based on the concept that the interfacial tension between the gas and crude oil phases at reservoir temperature must reduce to zero as these two phases approach the point of Miscibility. The concept of zero interfacial tension at Miscibility is, in turn, based on the well-accepted fact that the interface between the phases must vanish, as they become miscible with one another. Our results show the MMP value obtained from VIT method exceeds the slim tube MMP and Miscibility Pressure does not necessarily occur at zero IFT. Using zero IFT criteria cause MMP overestimation. In this study, by using the VIT and slim tube test, we measured the IFT in which slim tube MMP occur in VIT test for CO 2 –oil system for various types of reservoir oil. These IFT values are correlated by oil properties and test condition to help us measure the accurate value of MMP by using VIT method.

  • Modified vanishing interfacial tension (VIT) test for CO2–oil Minimum Miscibility Pressure (MMP) measurement
    Journal of Natural Gas Science and Engineering, 2014
    Co-Authors: Mehdi Ghorbani, Ali Momeni, Saied Safavi, Asghar Gandomkar
    Abstract:

    Abstract Miscible gas injection is one of the most popular and applicable enhanced oil recovery method in oil fields. Minimum Miscibility Pressure (MMP) is an important parameter for an enhanced oil recovery process involving carbon dioxide or hydrocarbon miscible gas injection. There are many methods for measuring MMP but the most standard method for measuring MMP value in oil field gas injection process is slim tube method, which is very time consuming (4–6 weeks). Measurements of the interfacial tension of mixtures of a reservoir fluid and injection gas at various Pressures have been proposed recently as an experimental method for predicting the Minimum Miscibility Pressure (MMP) in an experiment called the vanishing interfacial tension (VIT) technique. This method is quantitative in nature and fast (2–3 days) with respect to slim tube method. VIT technique is based on the concept that the interfacial tension between the gas and crude oil phases at reservoir temperature must reduce to zero as these two phases approach the point of Miscibility. The concept of zero interfacial tension at Miscibility is, in turn, based on the well-accepted fact that the interface between the phases must vanish, as they become miscible with one another. Our results show the MMP value obtained from VIT method exceeds the slim tube MMP and Miscibility Pressure does not necessarily occur at zero IFT. Using zero IFT criteria cause MMP overestimation. In this study, by using the VIT and slim tube test, we measured the IFT in which slim tube MMP occur in VIT test for CO 2 –oil system for various types of reservoir oil. These IFT values are correlated by oil properties and test condition to help us measure the accurate value of MMP by using VIT method.

Samane Moghadam - One of the best experts on this subject based on the ideXlab platform.

Morteza Nobakht - One of the best experts on this subject based on the ideXlab platform.

Yongan Gu - One of the best experts on this subject based on the ideXlab platform.

  • determination of co2 Minimum Miscibility Pressure from measured and predicted equilibrium interfacial tensions
    Industrial & Engineering Chemistry Research, 2008
    Co-Authors: Morteza Nobakht, Samane Moghadam, Yongan Gu
    Abstract:

    Accurate determination of the Minimum Miscibility Pressure (MMP) of a crude oil−CO2 system at the actual reservoir temperature is required in order to determine whether CO2 flooding is immiscible or miscible under the actual reservoir Pressure. The objective of this study is to determine the MMPs of a crude oil−CO2 system from its measured and predicted equilibrium interfacial tension (IFT) versus equilibrium Pressure data at a constant temperature. In the experiment, first, the CO2 solubilities in the crude oil are measured under four different equilibrium Pressures. Second, the equilibrium IFTs of the crude oil−CO2 system are measured at 12 different equilibrium Pressures and a constant temperature of T = 27 °C by applying the axisymmetric drop shape analysis (ADSA) technique for the pendant drop case. The detailed experimental results show that the CO2 solubility in the crude oil is increased almost linearly with the equilibrium Pressure. It is also found that the measured crude oil−CO2 equilibrium IFT...