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George J. Hirasaki - One of the best experts on this subject based on the ideXlab platform.
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Non-uniqueness, Numerical Artifacts, and Parameter Sensitivity in Simulating Steady-State and Transient Foam Flow Through Porous Media
Transport in Porous Media, 2014Co-Authors: Rouhi Farajzadeh, Jose Luis Lopez-salinas, Clarence A. Miller, Sibani Lisa Biswal, George J. HirasakiAbstract:The uniqueness and sensitivity of foam modeling parameters are crucial for simulating foam flow through porous media. In the absence of oil in the porous medium, the local-equilibrium foam model investigated in this work uses three parameters to describe the foam quality dependence: $$fmmob,\, fmdry$$ f m m o b , f m d r y , and $$epdry$$ e p d r y . Even for a specified value of $$epdry$$ e p d r y , in some cases, two pairs of $$fmmob$$ f m m o b and $$fmdry$$ f m d r y values can experimentally match measured transition foam quality ( $$f_\mathrm{g}^{t}$$ f g t ) and transition foam apparent viscosity ( $$\mu _\mathrm{foam,app}^t$$ μ foam , app t ). This non-uniqueness can be broken by limiting the solution such that $$fmdry$$ f m d r y is smaller than the transition Water Saturation ( $$S_\mathrm{w}^t$$ S w t ). In addition, a three-parameter fit using all experimental data of apparent viscosity versus foam quality was developed to simultaneously estimate $$fmmob,\, fmdry$$ f m m o b , f m d r y , and $$epdry$$ e p d r y . However, a better strategy is to conduct and match a transient experiment, in addition to steady-state experiments, in which a gas displaces the surfactant solution at 100 % Water Saturation. This transient foam quality scans the entire range of fractional flow, and the values of the foam parameters that best match the experiment can be uniquely determined. The numerical artifact of pressure oscillations in simulating this transient foam process was investigated by comparing the finite difference algorithm with the method of characteristics. Sensitivity analyses indicated that the estimated foam parameters were highly dependent on the parameters used for the Water and gas relative permeabilities. In particular, the Water relative permeability exponent and Connate Water Saturation are important.
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Non-uniqueness, Numerical Artifacts, and Parameter Sensitivity in Simulating Steady-State and Transient Foam Flow Through Porous Media
Transport in Porous Media, 2014Co-Authors: Rouhi Farajzadeh, Jose Luis Lopez-salinas, Clarence A. Miller, Sibani Lisa Biswal, George J. HirasakiAbstract:The uniqueness and sensitivity of foam modeling parameters are crucial for simulating foam flow through porous media. In the absence of oil in the porous medium, the local-equilibrium foam model investigated in this work uses three parameters to describe the foam quality dependence: \(fmmob,\, fmdry\), and \(epdry\). Even for a specified value of \(epdry\), in some cases, two pairs of \(fmmob\) and \(fmdry\) values can experimentally match measured transition foam quality (\(f_\mathrm{g}^{t}\)) and transition foam apparent viscosity (\(\mu _\mathrm{foam,app}^t\)). This non-uniqueness can be broken by limiting the solution such that \(fmdry\) is smaller than the transition Water Saturation (\(S_\mathrm{w}^t\)). In addition, a three-parameter fit using all experimental data of apparent viscosity versus foam quality was developed to simultaneously estimate \(fmmob,\, fmdry\), and \(epdry\). However, a better strategy is to conduct and match a transient experiment, in addition to steady-state experiments, in which a gas displaces the surfactant solution at 100 % Water Saturation. This transient foam quality scans the entire range of fractional flow, and the values of the foam parameters that best match the experiment can be uniquely determined. The numerical artifact of pressure oscillations in simulating this transient foam process was investigated by comparing the finite difference algorithm with the method of characteristics. Sensitivity analyses indicated that the estimated foam parameters were highly dependent on the parameters used for the Water and gas relative permeabilities. In particular, the Water relative permeability exponent and Connate Water Saturation are important.
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Estimation of Parameters for the Simulation of Foam Flow through Porous Media: Part 3; Non-Uniqueness, Numerical Artifact and Sensitivity
SPE Enhanced Oil Recovery Conference, 2013Co-Authors: Rouhi Farajzadeh, Jose Luis Lopez-salinas, Clarence A. Miller, Sibani Lisa Biswal, George J. HirasakiAbstract:In the absence of oil in the porous medium, the STARS foam model has three parameters to describe the foam quality dependence, fmmob , fmdry , and epdry . Even for a specified value of epdry , two pairs of values of fmmob and fmdry can sometimes match experimentally measured t g f and t app foam, μ . This non-uniqueness can be broken by limiting the solution to the one for which fmdry < t w S . Additionally, a three-parameter search is developed to simultaneously estimate the parameters fmmob , fmdry , and epdry that fit the transition foam quality and apparent viscosity. However, a better strategy is to conduct and match a transient experiment in which 100% gas displaces surfactant solution at 100% Water Saturation. This transient scans the entire range of fractional flow and the values of the foam parameters that best match 2 the experiment can be uniquely determined. Finally, a three-parameter fit using all experimental data of apparent viscosity versus foam quality is developed. The numerical artifact of pressure oscillations in simulating this transient foam process is investigated by comparing finite difference algorithm with method of characteristics. Sensitivity analysis shows that the estimated foam parameters are very dependent on the parameters for the Water and gas relative permeability. In particular, the Water relative permeability exponent and Connate Water Saturation are important.
Masoud Riazi - One of the best experts on this subject based on the ideXlab platform.
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The impact of Connate Water Saturation and salinity on oil recovery and CO2 storage capacity during carbonated Water injection in carbonate rock
Chinese Journal of Chemical Engineering, 2019Co-Authors: Mahmood Shakiba, Masoud Riazi, Shahab Ayatollahi, Mostafa TakbandAbstract:Abstract Carbonated Water injection (CWI) is known as an efficient technique for both CO2 storage and enhanced oil recovery (EOR). During CWI process, CO2 moves from the Water phase into the oil phase and results in oil swelling. This mechanism is considered as a reason for EOR. Viscous fingering leading to early breakthrough and leaving a large proportion of reservoir un-swept is known as an unfavorable phenomenon during flooding trials. Generally, instability at the interface due to disturbances in porous medium promotes viscous fingering phenomenon. Connate Water makes viscous fingers longer and more irregular consisting of large number of tributaries leading to the ultimate oil recovery reduction. Therefore, higher in-situ Water content can worsen this condition. Besides, this Water can play as a barrier between oil and gas phases and adversely affect the gas diffusion, which results in EOR reduction. On the other hand, from gas storage point of view, it should be noted that CO2 solubility is not the same in the Water and oil phases. In this study for a specified Water salinity, the effects of different Connate Water Saturations (Swc) on the ultimate oil recovery and CO2 storage capacity during secondary CWI are being presented using carbonate rock samples from one of Iranian carbonate oil reservoir. The results showed higher oil recovery and CO2 storage in the case of lower Connate Water Saturation, as 14% reduction of Swc resulted in 20% and 16% higher oil recovery and CO2 storage capacity, respectively.
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precipitation and deposition of asphaltene in porous media impact of various Connate Water types
Journal of Molecular Liquids, 2018Co-Authors: H Doryani, Mohammad Reza Malayeri, Masoud RiaziAbstract:Abstract The precipitation and deposition of asphaltene are among the least understood phenomena in upstream to downstream oil-related processes. The present experimental study investigated the impact of different Connate Water types on precipitation and deposition of asphaltene from synthetic oil solutions comprising of toluene, n-heptane with 5 wt% of asphaltene in a uniformly patterned glass micromodel. To do so, different types of Connate Water including deionized Water (DW) and brines such as CaCl2, MgCl2, KCl, NaCl, and Na2SO4 ranging from 5000 to 40,000 ppm were investigated. It was found that the type of cations present in the brine would profoundly influence the precipitation of asphaltene, probably due to their higher affinity toward anionic components. Divalent cations were also found to cause much more severe asphaltene precipitation compared to monovalent cations. Connate Water Saturation of different brines was also found to have diverse impact on precipitation and deposition of asphaltene given the type of cations present in the aqueous phase. Moreover, brine concentration influenced the amount of precipitated asphaltene due to the salting-in and salting-out effects.
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Experimental study of gravity drainage during gas injection in carbonate rocks
Canadian International Petroleum Conference, 2013Co-Authors: Masoud Riazi, A. H. Alizadeh, Manouchehr HaghighiAbstract:The purpose of this paper is to investigate the effect of injection rate, gravity force and Connate Water Saturation on the mechanism of gravity drainage. Gravity drainage is the most important mechanism in oil recovery from the fractured reservoirs. During gas injection gravity drainage may either become more effective or retard the process. Finding the optimum injection rate is our main goal in this study. In our experiments nitrogen and kerosene were used as gas and oil respectively. The core samples were prepared from outcrop of Asmari formation of Iran, which was a fractured carbonate rock. The injection gas rate is an important factor affecting on the oil recovery .We found a critical rate in which the gas rate is lower or higher than critical, the oil recovery decreases. However the recovery factor at critical rate is the maximum .This phenomena was discussed based on the competition of different forces of viscous, capillary and gravity .These forces cause the displacement change from the stable piston like displacement to an unstable trapping displacement. Observation showed that different amount of the gravity forces have no effect on oil recovery before gas breakthrough; however, with more gravity force, more oil production was observed after breakthrough. Also, we observed irreducible Water Saturation change during gas injection in our carbonate rocks.M. Riazi, A. H. Alizadeh, M. Haghigh
Mohammad Hossein Ghazanfari - One of the best experts on this subject based on the ideXlab platform.
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Experimental and numerical investigation of polymer flooding in fractured heavy oil five-spot systems
Journal of Petroleum Science and Engineering, 2013Co-Authors: Mohammad Hossein Sedaghat, Mohammad Hossein Ghazanfari, Mohsen Masihi, Davood RashtchianAbstract:Microscopic and macroscopic displacements of polymer flooding to heavy oil at various levels of salinity and Connate Water Saturation have been investigated. Both oil-wet and Water-wet conditions in fractured five-spot micromodel systems, initially saturated with the heavy crude oil are utilized. The primary contribution is to examine the role of salinity, wettability, Connate Water, and fracture geometry in the recovery efficiency of the system. The microscopic results revealed that the increase in the Connate Water Saturation decreases the oil recovery, independent of the wettability conditions. Moreover, the increase in salinity of the injected fluids lowers the recovery efficiency due to the decrease in polymer viscosity. One the other hand, the microscopic results emphasized the wettability role in the simultaneous flow of oil, the Connate Water, and the polymer phases. In addition, switching from the oil-wet to the Water-wet medium has manifested increase in the oil recovery during polymer flooding as compared to Water flooding owing to its severe mechanisms of pulling and stripping. To simulate the experimental results, the UTCHEM software has been applied, which has validated the observed data for different fractured patterns, and at various Connate Water and salinity of polymer solution. Furthermore, the visualized results uncovered a light stripping mechanism in the high permeable fracture. The findings of this study can be beneficial to the better understanding of the microscopic/macroscopic displacements during polymer flooding in fractured heavy oil five-spot systems. It also illustrates the successful application of the UTCHEM for predicting the roles of Connate Water, salinity and fracture geometry in efficiency of polymer flooding in fractured five-spot micromodels.
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An Experimental Investigation of Foam for Gas Mobility Control in a Low-Temperature Fractured Carbonate Reservoir
Petroleum Science and Technology, 2012Co-Authors: Asghar Gandomkar, Riyaz Kharrat, M. Motealleh, Hamid Hosseinzade Khanamiri, M. Nematzadeh, Mohammad Hossein GhazanfariAbstract:Abstract This work concerns the experimental investigation of surfactant alternating CO2 injection in carbonate rocks. The core samples provided from a low-temperature fractured light oil reservoir, located in southwest Iran. The experiments were designed to observe the effect of CO2–foam injection on gas mobility and oil recovery at different surfactant concentrations. The core samples were initially saturated with synthetic/field brine, 5,000 ppm, and then flooded with live oil to reach Connate Water Saturation at reservoir condition, 115°F and 1,700 psia. The commercial surfactant used was sodium lauryl sulfate as an anionic surfactant. The results of this work, along with field-scale simulation and/or economic considerations, could be helpful in making reliable decisions about optimum condition of foam-assisted Water-alternating-gas (FAWAG) processes. Core flooding results demonstrated that macroscopic sweep efficiency increased due to foam generation inside the core. In addition, it led to an increas...
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characterizing the role of shale geometry and Connate Water Saturation on performance of polymer flooding in heavy oil reservoirs experimental observations and numerical simulations
Transport in Porous Media, 2012Co-Authors: Saber Mohammadi, Mohsen Masihi, Mohammad Hossein GhazanfariAbstract:Many heavy oil reservoirs contain discontinuous shales which act as barriers or baffles to flow. However, there is a lack of fundamental understanding about how the shale geometrical characteristics affect the reservoir performance, especially during polymer flooding of heavy oils. In this study, a series of polymer injection processes have been performed on five-spot glass micromodels with different shale geometrical characteristics that are initially saturated with the heavy oil. The available geological characteristics from one of the Iranian oilfields were considered for the construction of the flow patterns by using a controlled-laser technology. Oil recoveries as a function of pore volumes of injected fluid were determined from analysis of continuously recorded images during the experiments. We observed a clear bypassing of displacing fluid which results in premature breakthrough of injected fluid due to the shale streaks. Moreover, the results showed a decrease of oil recovery when shales’ orientation, length, spacing, distance of the shale from production well, and density of shales increased. In contrast, an increase of shale discontinuity or distance of the shale streak from the injection well increased oil recovery. The obtained experimental data have also been used for developing and validating a numerical model where good matching performance has been observed between our experimental observations and simulation results. Finally, the role of Connate Water Saturation during polymer flooding in systems containing flow barriers has been illustrated using pore level visualizations. The microscopic observations confirmed that besides the effect of shale streaks as heterogeneity in porous medium, when Connate Water is present, the trapped Water demonstrates another source of disturbance and causes additional perturbations to the displacement interface leading to more irregular fingering patterns especially behind the shale streaks and also causes a reduction of ultimate oil recovery. This study reveals the application of glass micromodel experiments for studying the effects of barriers on oil recovery and flow patterns during EOR processes and also may provide a set of benchmark data for recovery of oil by immiscible polymer flood around discontinuous shales.
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an experimental and numerical investigation of solvent injection to heavy oil in fractured five spot micromodels
Petroleum Science and Technology, 2010Co-Authors: Seyed Amir Farzaneh, Mohammad Hossein Ghazanfari, Riyaz Kharrat, Shapour VossoughiAbstract:Abstract In this work a series of solvent injection experiments was conducted on horizontal glass micromodels at several fixed flow rate conditions. The micromodels were initially saturated with heavy crude oil. The produced oil as a function of injected volume of solvents was measured using image analysis of the continuously provided pictures. In order to investigate the macroscopic behavior of the process in different media, several fractured, with constant width, and nonfractured five-spot micromodels were designed and used. The measured data have also been used for verifying and developing a simulation model that was later used for sensitivity analysis of some parameters that affect oil recovery. The results show that when the fracture spacing increased, the oil recovery decreased. In contrast, as the fracture orientation angle (the angle with the mean flow direction) or solvent viscosity increased, the oil recovery increased. A critical value for the ratio of Connate Water Saturation to the oil volum...
Zhangxin Chen - One of the best experts on this subject based on the ideXlab platform.
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study of heat transfer by thermal expansion of Connate Water ahead of a steam chamber edge in the steam assisted gravity drainage process
Fuel, 2015Co-Authors: He Zhong, Mingzhe Dong, Zhangxin ChenAbstract:Abstract Steam-Assisted Gravity Drainage (SAGD) has been the preferred thermal method for bitumen recovery from reservoirs in western Canada, such as Athabasca and Cold Lake. In SAGD, near the edge of a steam chamber, the viscosity of bitumen can be reduced by several orders of magnitude by the release of latent heat from injected steam. Consequently, the heated bitumen flows downwards to a horizontal production well, under the action of gravity. A critical control of oil production performance in SAGD is the heat transfer ahead of the steam chamber edge. It is commonly suggested that heat conduction is the only, or dominant, mechanism for heat to be transferred to the cold oil sands. Heat transfer through convection is neglected in classical models, such as in Butler’s theory. Although a few mathematical studies have recently been performed to examine the role of convective heat transfer through condensate flow perpendicular or parallel to the steam chamber edge, the role of heat transfer by cold Connate Water thermal expansion in SAGD has been given little attention. In this study, an analytical model is derived for heat transfer induced by thermal expansion of the Connate Water, and the result is reasonably consistent with the numerical simulation results obtained by running CMG STARS. The relative roles of conduction and convection ahead of the steam chamber edge are re-examined. The results show that heat convection accounts for a much higher percentage of the total heat transfer than conduction. This study also suggests that parameters that have a close relationship with the thermal expansion of Connate Water, such as the steam injection temperature and Connate Water Saturation, can affect the relative roles of conductive and convective heat transfer in SAGD. Based on this study, the heat transfer efficiency can be enhanced through improving convection induced by thermal expansion of Connate Water.
Rouhi Farajzadeh - One of the best experts on this subject based on the ideXlab platform.
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Non-uniqueness, Numerical Artifacts, and Parameter Sensitivity in Simulating Steady-State and Transient Foam Flow Through Porous Media
Transport in Porous Media, 2014Co-Authors: Rouhi Farajzadeh, Jose Luis Lopez-salinas, Clarence A. Miller, Sibani Lisa Biswal, George J. HirasakiAbstract:The uniqueness and sensitivity of foam modeling parameters are crucial for simulating foam flow through porous media. In the absence of oil in the porous medium, the local-equilibrium foam model investigated in this work uses three parameters to describe the foam quality dependence: $$fmmob,\, fmdry$$ f m m o b , f m d r y , and $$epdry$$ e p d r y . Even for a specified value of $$epdry$$ e p d r y , in some cases, two pairs of $$fmmob$$ f m m o b and $$fmdry$$ f m d r y values can experimentally match measured transition foam quality ( $$f_\mathrm{g}^{t}$$ f g t ) and transition foam apparent viscosity ( $$\mu _\mathrm{foam,app}^t$$ μ foam , app t ). This non-uniqueness can be broken by limiting the solution such that $$fmdry$$ f m d r y is smaller than the transition Water Saturation ( $$S_\mathrm{w}^t$$ S w t ). In addition, a three-parameter fit using all experimental data of apparent viscosity versus foam quality was developed to simultaneously estimate $$fmmob,\, fmdry$$ f m m o b , f m d r y , and $$epdry$$ e p d r y . However, a better strategy is to conduct and match a transient experiment, in addition to steady-state experiments, in which a gas displaces the surfactant solution at 100 % Water Saturation. This transient foam quality scans the entire range of fractional flow, and the values of the foam parameters that best match the experiment can be uniquely determined. The numerical artifact of pressure oscillations in simulating this transient foam process was investigated by comparing the finite difference algorithm with the method of characteristics. Sensitivity analyses indicated that the estimated foam parameters were highly dependent on the parameters used for the Water and gas relative permeabilities. In particular, the Water relative permeability exponent and Connate Water Saturation are important.
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Non-uniqueness, Numerical Artifacts, and Parameter Sensitivity in Simulating Steady-State and Transient Foam Flow Through Porous Media
Transport in Porous Media, 2014Co-Authors: Rouhi Farajzadeh, Jose Luis Lopez-salinas, Clarence A. Miller, Sibani Lisa Biswal, George J. HirasakiAbstract:The uniqueness and sensitivity of foam modeling parameters are crucial for simulating foam flow through porous media. In the absence of oil in the porous medium, the local-equilibrium foam model investigated in this work uses three parameters to describe the foam quality dependence: \(fmmob,\, fmdry\), and \(epdry\). Even for a specified value of \(epdry\), in some cases, two pairs of \(fmmob\) and \(fmdry\) values can experimentally match measured transition foam quality (\(f_\mathrm{g}^{t}\)) and transition foam apparent viscosity (\(\mu _\mathrm{foam,app}^t\)). This non-uniqueness can be broken by limiting the solution such that \(fmdry\) is smaller than the transition Water Saturation (\(S_\mathrm{w}^t\)). In addition, a three-parameter fit using all experimental data of apparent viscosity versus foam quality was developed to simultaneously estimate \(fmmob,\, fmdry\), and \(epdry\). However, a better strategy is to conduct and match a transient experiment, in addition to steady-state experiments, in which a gas displaces the surfactant solution at 100 % Water Saturation. This transient foam quality scans the entire range of fractional flow, and the values of the foam parameters that best match the experiment can be uniquely determined. The numerical artifact of pressure oscillations in simulating this transient foam process was investigated by comparing the finite difference algorithm with the method of characteristics. Sensitivity analyses indicated that the estimated foam parameters were highly dependent on the parameters used for the Water and gas relative permeabilities. In particular, the Water relative permeability exponent and Connate Water Saturation are important.
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Estimation of Parameters for the Simulation of Foam Flow through Porous Media: Part 3; Non-Uniqueness, Numerical Artifact and Sensitivity
SPE Enhanced Oil Recovery Conference, 2013Co-Authors: Rouhi Farajzadeh, Jose Luis Lopez-salinas, Clarence A. Miller, Sibani Lisa Biswal, George J. HirasakiAbstract:In the absence of oil in the porous medium, the STARS foam model has three parameters to describe the foam quality dependence, fmmob , fmdry , and epdry . Even for a specified value of epdry , two pairs of values of fmmob and fmdry can sometimes match experimentally measured t g f and t app foam, μ . This non-uniqueness can be broken by limiting the solution to the one for which fmdry < t w S . Additionally, a three-parameter search is developed to simultaneously estimate the parameters fmmob , fmdry , and epdry that fit the transition foam quality and apparent viscosity. However, a better strategy is to conduct and match a transient experiment in which 100% gas displaces surfactant solution at 100% Water Saturation. This transient scans the entire range of fractional flow and the values of the foam parameters that best match 2 the experiment can be uniquely determined. Finally, a three-parameter fit using all experimental data of apparent viscosity versus foam quality is developed. The numerical artifact of pressure oscillations in simulating this transient foam process is investigated by comparing finite difference algorithm with method of characteristics. Sensitivity analysis shows that the estimated foam parameters are very dependent on the parameters for the Water and gas relative permeability. In particular, the Water relative permeability exponent and Connate Water Saturation are important.