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Mehran Sohrabi - One of the best experts on this subject based on the ideXlab platform.
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An Experimental Investigation of the Effect of Rock Wettability on the Performance of Carbonated Water Injection (CWI)
2020Co-Authors: Jaime Castaneda, Almohannad Alghamdi, Amir Farzaneh, Mehran SohrabiAbstract:Abstract Wettability is often considered one of the most relevant variables in any conventional Water injection process as it dominates the microscopic distribution of fluids in the porous medium, determines the amount of residual oil, and defines the ability with which a phase can flow. On the other hand, Carbonated Water injection is an enhanced oil recovery technique, where basically Water saturated with CO2 is injected along the reservoir with the benefits of Water displacement together with the benefits of CO2 injection, without the great disadvantages of poor sweeping causing low areal efficiency. In addition, it has been proven that the transfer of CO2 from the aqueous phase to the oil phase, in one way, promotes the generation of what has been called a new gas phase, which is the main responsible for the incremental oil production, and which mainly attacks the residual oil saturation. Numerous experiments performed in the past on micro models, and plugs have shown that the injection of Carbonated Water plays an important role in the wettability of the rock. The injection has been demonstrated a change in the wettability to a Water-wet because there is a reduction in the pH of the aqueous phase, and this is expected to modify the charges on the oil/Water, and Water/rock interfaces, and hence the wettability of the system. The dissolution of CO2, into the oil phase, and the destabilization of the polar components of the oil also may shift the wettability more towards Water-wet, which favours a later Water breakthrough, and a higher oil recovery factor. However, none of these experiments, as far as the author is informed, have been performed on whole cores, nor have these experiments used live crude oil with multi-component gases in solution, which would be closer to reality. This research seeks to close this gap by performing a new series of core floods to understand, from an engineering point of view, what effect the injection of Carbonated Water has on wettability in circumstances more realistic. From these analyses it was concluded that rock wettability plays an important role on the differential pressure behaviour for both Waterflooding, and Carbonated Water injection. A mix/oil-wet rock causes a greater differential pressure response. A much higher differential pressure is obtained when Carbonated Water injection is started. This is assumed to be due to the formation of the new gas phase. A greater oil recovery factor is obtained in a Water-wet system when both secondary Waterflooding, and tertiary CWI oil recovery are summed. However, when only tertiary injection of Carbonated Water is analysed, a higher oil recovery is obtained in mix/oil-wet systems. The new gas phase formation is facilitated in mix/oil-wet systems. The methane content dissolved in live oil plays the main role for oil recovery, and differential pressure behaviour in a Carbonated Water injection process. It is inversely related to the pressure behaviour, and oil recovery. This occurs because a low methane content allows a higher formation of the new gas phase, and therefore a higher production of oil; however, the differential pressure increases at the same time. Viscosity reduction due to CO2 mass transfer has a smaller effect in oil recovery, and differential pressure than the effect caused by the formation of a new gas phase. In the experiments that were conducted, the author calculated a novel linear relationship between new gas phase saturation, and tertiary oil recovery. This relationship is almost constant irrespective of the oil, and gas compositions and the wettability of the rock. This approach would allow the calculation of the additional tertiary oil recovery potential by the injection of Carbonated Water, based only on the saturation behaviour of the new gas phase; therefore the new objective of this recovery method would be to maximise the formation of this new phase. Although at laboratory scale there are different methods to determine the wettability of a rock, sometimes it is not possible to perform such measurements. Therefore, the author proposes a novel method that identifies trends in wettability, or better, compares trends based on Darcy's equation. This method was applied to the experiments conducted in this research, and its results were corroborated by other approaches available in the industry. Based on the results, it is possible to infer that by using a whole core the wettability change effect associated with the injection of Carbonated Water is not so preponderant, on the contrary, it could be more affected by the methane content in the system. The experiments conducted prior to this research had been focused on micro-models, and 1 to 2 inch diameter core evaluations, where the analysis was restricted to pore level or small scale behaviour, systems in which the impact of pore level wettability change is much greater.
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Carbonated Water injection under reservoir conditions; in-situ WAG-type EOR
Fuel, 2018Co-Authors: Pedram Mahzari, Mehran Sohrabi, Pantelis Tsolis, Enezi, Ali A. Yousef, Ahmed A. EidanAbstract:Abstract Enriching injection Water with CO2 has demonstrated promising results as a method for improving the oil recovery and securely storing CO2 in oil reservoirs. However, mutual interactions taking place between Carbonated Water and reservoir oil at elevated reservoir conditions are not fully understood. Herein, we present the results of a thorough and direct investigation of the interactions between live-oil/CO2/aqueous-phase leading to additional oil recovery and enhanced CO2 storage in pore-scale and core-scale. CO2 transfer from Carbonated Water to live oils can trigger liberation of light components in form of a new gaseous phase. This unique phenomenon would bring about higher degrees of oil swelling, and it can also create a three phase flow regime, which leads to effective reduction of residual oil saturation. The observations confirm that the performance of Carbonated Water injection (CWI) should be investigated under reservoir conditions using multi-components live oil and reservoir cores. From the core displacement tests, it was observed that secondary CWI could recover a significant amount of additional oil, which was 26% compared to conventional seaWater injection. When CO2 content of injected CW (Carbonated Water) was halved, the oil recovery dropped by 1/3 Using live oils, it was found out that CO2 would be trapped in the new phase, which brings about an enhanced CO2 trapping mechanism. Under realistic reservoir conditions where complex mass transfer of CO2 from aqueous phase to oil and gas phases takes place, an “in-situ WAG-type” three-phase flow is generated with more effective sweep efficiency and pore-scale advantages.
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A comparative study of oil compositional variations during CO2 and Carbonated Water injection scenarios for EOR
Journal of Petroleum Science and Engineering, 2018Co-Authors: Mojtaba Seyyedi, Pedram Mahzari, Mehran SohrabiAbstract:Abstract With the significant increase in the atmospheric concentration of CO 2 , the interest for a combination of Enhanced Oil Recovery (EOR) and safe underground storage of CO 2 in oil reservoirs has been increased. Two applicable methods that can address these concerns are CO 2 flooding and Carbonated Water injection (CWI). Mutual interactions taking place between oil and free CO 2 or Carbonated Water (i.e. dissolve CO 2 in the aqueous phase) would possess a fundamental difference. For free CO 2 and oils, a combination of condensing/vaporizing type of mass transfer would occur. However, in the case of Carbonated Water, a one-way mass transfer of CO 2 from the aqueous phase to the oil can take place. This would lead to significant differences in the oil properties after dynamic interactions with free CO 2 or Carbonated Water. In this study, for the first time, we are aiming to comprehensively address these concerns. An integrated approach was conducted to perform a series of carefully designed high-pressure and high-temperature direct visualizations (micromodel) as well as contact (PVT) experiments using a representative live oil. The results of pore-scale visualization experiments revealed an adverse strong extraction taking place during CO 2 injection. Due to this extraction, the remaining oil after CO 2 flooding was heavier than the original oil and its production was even more difficult. Contrary to that, during CWI the resident oil became lighter (lower viscosity) and no evidence of substantial extraction or oil downgrading was observed. To confirm pore-scale observations, PVT experiments were performed that revealed a strong adverse compositional change happening during CO 2 -oil single contact test. The oil contacted with CO 2 was heavier than the original oil and a heavy condensate formed mainly from the medium components of oil was produced. However, during CW-oil multiple contacts test, the oil composition did not change and only after extensive cell volumes of CW comes in contact with the live oil; a slight change in the oil composition was observed. This slight change was due to the small extraction of light components of the oil into the new gaseous phase and it was observed in the form of a condensate. The produced condensate was lighter than the one produced from CO 2 -oil single contact test that reveals even after significant cell volumes of CW comes in contact with oil, the compositional change in oil is negligible compared to that of CO 2 injection. The results of this study will shed some lights on the complex fluid-fluid interactions and oil compositional variations that take place during conventional CO 2 and Carbonated Water injection in oil reservoirs.
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A comprehensive experimental study of pore-scale and core-scale processes during Carbonated Water injection under reservoir conditions
Day 2 Tue April 25 2017, 2017Co-Authors: Pedram Mahzari, Mehran Sohrabi, Pantelis Tsolis, Enezi, Ali A. Yousef, S. Amir Farzaneh, Ahmed A. EidanAbstract:Enriching the injection Water with CO2 has demonstrated promising results as a method for improving oil recoveries and securely storing CO2 in oil reservoirs. However, the mutual interactions taking place between Carbonated Water and reservoir oil at elevated reservoir conditions are not fully understood. Here we present the results of a thorough investigation of the processes leading to additional oil recovery through integrating pore-scale visualisations and coreflood experiments. Four pore-scale visualization (micromodel) experiments were performed at reservoir conditions using the recombined live oil under different injection scenarios (tertiary and secondary). Having identified the underlying dynamic interactions at pore-scales, the performance of different injection scenarios for Carbonated Water injection (CWI) was investigated using carbonate reservoir rocks. Five coreflood experiments were carried out using both fully and half-saturated Carbonated Water to sensitise the impact of CO2 content of injection Water on the performance of CWI. In-situ liberation of gaseous phase was identified (from direct visualisations) as the predominant mechanism controlling the performance of Carbonated Water injection. The gas phase formation would bring about higher degrees of oil swelling, and it would also create a three phase flow regime which leads to further reduction of residual oil saturation. The observations confirm that the performance of CWI should be investigated under reservoir conditions using multi-components live oil and reservoir cores. Any simplification, e.g. one components make-up gas or reduced pressure/temperature, of the reservoir conditions would misleadingly change the pore-scale event and hence, the performance of CWI. From the core displacement tests, it was observed that secondary CWI could recover a significant amount of additional oil, which was 26% compared to plain seaWater injection. The tertiary Carbonated Water would effectively mobilise 15.3% of the residual oil (after seaWater injection). When CO2 content of injected CW (Carbonated Water) was halved, the oil recovery dropped by 1/3. The results revealed that the oil recovery would be lower if CO2 concentration is reduced but the extent of oil recovery reduction would be much less than the level of reduction in CO2 concentration. The unique and integrated research approach employed here enables us to produce a more complete and reliable set of findings and understandings at realistic reservoir conditions. During CWI under reservoir conditions, an “in-situ WAG-type” three-phase flow would be generated with more effective sweep efficiency and pore-scale advantages.
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pore scale investigation of crude oil co2 compositional effects on oil recovery by Carbonated Water injection
Industrial & Engineering Chemistry Research, 2017Co-Authors: Mojtaba Seyyedi, Mehran SohrabiAbstract:Through coreflood and micromodel studies, it has been shown that Carbonated Water injection (CWI) can improve oil recovery compared to conventional Waterflood. However, in most early studies, either a refined oil or dead crude oil had been used, which is not representative of a real oil reservoir where the oil has significant dissolved gases. In such studies, oil swelling and oil viscosity reduction had been introduced as the main mechanisms of additional oil recovery by CWI. However, in our direct flow visualization (micromodel) studies reported here, we have used live crude oil, and we have observed the formation and growth of a new gaseous phase inside the oil when it comes in contact with Carbonated Water (CW). The aim of this work is to visually study the effect of this phenomenon on oil recovery by CWI at pore scale. In this paper, we present the results of two high-pressure high-temperature direct flow visualization (micromodel) experiments which have been performed using a live crude oil sample. T...
Mojtaba Seyyedi - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of oil compositional variations during CO2 and Carbonated Water injection scenarios for EOR
Journal of Petroleum Science and Engineering, 2018Co-Authors: Mojtaba Seyyedi, Pedram Mahzari, Mehran SohrabiAbstract:Abstract With the significant increase in the atmospheric concentration of CO 2 , the interest for a combination of Enhanced Oil Recovery (EOR) and safe underground storage of CO 2 in oil reservoirs has been increased. Two applicable methods that can address these concerns are CO 2 flooding and Carbonated Water injection (CWI). Mutual interactions taking place between oil and free CO 2 or Carbonated Water (i.e. dissolve CO 2 in the aqueous phase) would possess a fundamental difference. For free CO 2 and oils, a combination of condensing/vaporizing type of mass transfer would occur. However, in the case of Carbonated Water, a one-way mass transfer of CO 2 from the aqueous phase to the oil can take place. This would lead to significant differences in the oil properties after dynamic interactions with free CO 2 or Carbonated Water. In this study, for the first time, we are aiming to comprehensively address these concerns. An integrated approach was conducted to perform a series of carefully designed high-pressure and high-temperature direct visualizations (micromodel) as well as contact (PVT) experiments using a representative live oil. The results of pore-scale visualization experiments revealed an adverse strong extraction taking place during CO 2 injection. Due to this extraction, the remaining oil after CO 2 flooding was heavier than the original oil and its production was even more difficult. Contrary to that, during CWI the resident oil became lighter (lower viscosity) and no evidence of substantial extraction or oil downgrading was observed. To confirm pore-scale observations, PVT experiments were performed that revealed a strong adverse compositional change happening during CO 2 -oil single contact test. The oil contacted with CO 2 was heavier than the original oil and a heavy condensate formed mainly from the medium components of oil was produced. However, during CW-oil multiple contacts test, the oil composition did not change and only after extensive cell volumes of CW comes in contact with the live oil; a slight change in the oil composition was observed. This slight change was due to the small extraction of light components of the oil into the new gaseous phase and it was observed in the form of a condensate. The produced condensate was lighter than the one produced from CO 2 -oil single contact test that reveals even after significant cell volumes of CW comes in contact with oil, the compositional change in oil is negligible compared to that of CO 2 injection. The results of this study will shed some lights on the complex fluid-fluid interactions and oil compositional variations that take place during conventional CO 2 and Carbonated Water injection in oil reservoirs.
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Pore-Scale Investigation of Crude Oil/CO2 Compositional Effects on Oil Recovery by Carbonated Water Injection
Industrial & Engineering Chemistry Research, 2017Co-Authors: Mojtaba Seyyedi, Mehran SohrabiAbstract:Through coreflood and micromodel studies, it has been shown that Carbonated Water injection (CWI) can improve oil recovery compared to conventional Waterflood. However, in most early studies, either a refined oil or dead crude oil had been used, which is not representative of a real oil reservoir where the oil has significant dissolved gases. In such studies, oil swelling and oil viscosity reduction had been introduced as the main mechanisms of additional oil recovery by CWI. However, in our direct flow visualization (micromodel) studies reported here, we have used live crude oil, and we have observed the formation and growth of a new gaseous phase inside the oil when it comes in contact with Carbonated Water (CW). The aim of this work is to visually study the effect of this phenomenon on oil recovery by CWI at pore scale. In this paper, we present the results of two high-pressure high-temperature direct flow visualization (micromodel) experiments which have been performed using a live crude oil sample. T...
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pore scale investigation of crude oil co2 compositional effects on oil recovery by Carbonated Water injection
Industrial & Engineering Chemistry Research, 2017Co-Authors: Mojtaba Seyyedi, Mehran SohrabiAbstract:Through coreflood and micromodel studies, it has been shown that Carbonated Water injection (CWI) can improve oil recovery compared to conventional Waterflood. However, in most early studies, either a refined oil or dead crude oil had been used, which is not representative of a real oil reservoir where the oil has significant dissolved gases. In such studies, oil swelling and oil viscosity reduction had been introduced as the main mechanisms of additional oil recovery by CWI. However, in our direct flow visualization (micromodel) studies reported here, we have used live crude oil, and we have observed the formation and growth of a new gaseous phase inside the oil when it comes in contact with Carbonated Water (CW). The aim of this work is to visually study the effect of this phenomenon on oil recovery by CWI at pore scale. In this paper, we present the results of two high-pressure high-temperature direct flow visualization (micromodel) experiments which have been performed using a live crude oil sample. T...
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An integrated study of the dominant mechanism leading to improved oil recovery by Carbonated Water injection
Journal of Industrial and Engineering Chemistry, 2017Co-Authors: Mojtaba Seyyedi, Pedram Mahzari, Mehran SohrabiAbstract:Abstract Enriching the injection Water with CO2 has demonstrated encouraging results to improve oil recovery and securely store CO2 in underground oil reservoirs. However, the mutual interactions taking place between Carbonated Water and reservoir oils are not fully understood. Assuming that the phase behaviour of free CO2 and oil phase that takes place during conventional CO2 flood will also take place during Carbonated Water injection (CWI) would be misleading. Recently, it has been visually demonstrated that CO2 transfer from Carbonated Water into a “live” crude oil would trigger the formation of a new gaseous phase, which would hugely boost the performance of CWI under real reservoir conditions. Therefore, characterization of this new phase would have significant implications for identifying the suitable conditions at which CWI displaces the oil more efficiently. In this study, through a series of multiple-contact tests linked to micromodel and slim tube experiments, it has been aimed to comprehensively investigate; (i) CW–oil phase behaviour, (ii) the characteristic of gaseous new phase, and (iii) its impact on oil recovery by CWI, (iv) CW displacement front propagation inside the reservoir as CW moving far from injection point. We have studied the interactions between CW and live crude oil (crude oil with solution gas) by performing a series of high-pressure high-temperature fluid characterization tests. The live oil was sequentially brought into contact with CW and in each contact, the resultant phases were analysed to track the CO2 transfer between different phases and to determine the composition and characteristics of the new phase. The results revealed that the new phase forms immediately when live oil is brought into contact with the CO2-enriched Water and it grows at subsequent contacts. The results of gas chromatography analyses also reveal that the new phase is composed of a multi-component mixture of hydrocarbons starting with CH4 and CO2 at early stages and becoming richer in CO2 towards latter contacts. Alongside the multiple-contact experiment, direct visualisation experiments performed at identical conditions confirm the rapid formation and growth of the new phase for the live oil system. Furthermore, to assess CW–live oil phase behaviour and displacement front propagation over long distances inside the reservoir, two carefully designed slim tube experiments were performed to compare the performance of secondary CWI against the conventional Waterflooding in a one-dimensional long porous medium. The results of the slim tube tests showed that CWI led to an average improved oil recovery of 24% compared to conventional Water flood. The outcomes of this integrated investigation unravel the characteristic and impact of the new phase formation on improved oil recovery by CWI. This would enable us to identify and target suitable reservoirs for this EOR technique.
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Enhancing Water Imbibition Rate and Oil Recovery by Carbonated Water in Carbonate and Sandstone Rocks
Energy & Fuels, 2015Co-Authors: Mojtaba Seyyedi, Mehran SohrabiAbstract:Spontaneous imbibition is regarded as an important mechanism of oil recovery by Waterflood, particularly in heterogeneous or fractured reservoirs where direct displacement of oil by Water is usually poor. It has been shown that Carbonated Water injection (CWI) can improve recovery from oil reservoirs. It has also been reported that the dissolution of CO2 in Water can alter Water/oil contact angle, which is a direct indication of the wettability of a crude oil/Water/rock/system. In this work, our main objective was to experimentally investigate the potential of Carbonated Water for improving the rate of spontaneous imbibition of Water and, hence, the oil recovery from systems where spontaneous imbibition of Water would be important. To achieve this objective, a special high-pressure imbibition cell has been designed, and six spontaneous imbibition experiments have been performed on two different types of rocks (carbonate rock and sandstone) at a pressure of 2500 psi and room temperature. Crude oil was used...
Masoud Riazi - One of the best experts on this subject based on the ideXlab platform.
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An Investigation of Oil Spreading Coefficient in Carbonated Water+ Gas + Oil System: an Experimental Study in an Iranian Asphaltenic Oil Reservoir
Iranian Journal of Oil and Gas Science and Technology, 2018Co-Authors: Abdolah Golkari, Masoud Riazi, Amin AvazpourAbstract:To provide supplementary oil recovery after the primary and secondary processes, enhanced oil recovery (EOR) techniques are introduced. Carbonated Water injection (CWI) as an EOR method can improve sweep efficiency and the risk of gas leakage. On the other hand, the interfacial tension (IFT) is one of the key factors which can affect fluid displacement during the process of CWI greatly. Therefore, the analysis of the IFT on an oil-Carbonated Water-CO2 system is vital. In this paper, the interfacial interactions of binary systems of asphaltenic crude oil (ACO), carbon dioxide (CO2), and Carbonated Water (CW) at different pressures and at two temperatures of 40 °C and 50 °C and their effects on the oil spreading in the Water phase in the presence of gas are experimentally investigated. The IFT measurements were performed by axisymmetric drop shape analysis (ADSA) technique for the pendant/rising oil drop case. It is found out that the equilibrium interfacial tension (EIFT) of the two systems of crude oil-CO2 and Water-CO2 is reduced almost linearly with pressure but increased with temperature. Moreover, the pressure has an increasing and decreasing effect on the Water-oil and CW-oil IFT’s respectively. However, temperature has a reverse effect for the both systems. Spreading coefficient (SC) concept would help better understand the oil recovery mechanisms and potential. The results show that SC curve has a minimum point value as a specific pressure, which increases with temperature. The presence of CO2 in the Water phase could strongly affect the oil spreading phenomenon through which oil recovery could be significantly enhanced.
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Experimental investigation of dynamic swelling and Bond number of crude oil during Carbonated Water flooding; Effect of temperature and pressure
Fuel, 2018Co-Authors: Mostafa Lashkarbolooki, Masoud Riazi, Shahab AyatollahiAbstract:Abstract The potential of crude oil swelling is dominant mechanism in the development and implementation of Carbonated Water (CO 2 saturated Water) flooding as an environmental friendly enhanced oil recovery method. In this study, the volume of crude oil drop in Carbonated Water (CW) was measured at temperatures of 30, 50 and 80 °C and pressures of 500, 1000, 2000 and 4000 psi to investigate the swelling behavior of crude oil during CW flooding. In addition, the variations of dynamic and equilibrium Bond number of CW/crude oil due to dissolution of CO 2 in the crude oil are compared to the crude oil/Water systems. It is expected that crude oil swelling decreases as temperature increases due to a reduction of the concentration of CO 2 in the CW phase in all the studied pressures. However, interesting and unexpected results was observed. That is, the swelling of crude oil drops significantly different in two distinct regions: in the first region (i.e. pressure lower than crossover), the swelling of crude oil decreases when temperature increases; in the second region (i.e. pressure higher than crossover), the behavior of the crude oil swelling versus temperature is in the opposite of that in the first region.
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Experimental investigation of the impact of rock dissolution on carbonate rock properties in the presence of Carbonated Water
Environmental Earth Sciences, 2016Co-Authors: Mohsen Abbaszadeh, Masoud Nasiri, Masoud RiaziAbstract:Carbon dioxide (CO2) storage in aquifers or injection to petroleum reservoirs for enhanced oil recovery purposes are the ways of mitigation of global warming. Dissolution of carbon dioxide in Water forms carbonic acid. This acid would react with the carbonate components in carbonate rocks (i.e., CaCO3, MgCO3) and cause dissolution of salts thereafter changing carbonate rocks intrinsic properties. Dissolution changes the properties of carbonate rocks. To investigate these phenomena, two carbonate rock samples were saturated with brine and brought in contact with Carbonated Water for about 12 days. After each 72-h period, porosity, permeability, the mass of the cores and concentration of released ions in brine were measured. Concentrations of released ions were calculated by titration in each period. A considerable change on rock properties was observed. Porosity and permeability changes were about +8.09 and ±9.73 %, respectively, and core weight loss was about 0.82 Wt %. Besides, intensity of the concentration of released magnesium ions in brine with comparison to calcium ions indicates that the core samples are dolomite. The results of this study show that carbonate rock dissolution should be considered in Water alternative CO2 injection, Carbonated Water injection and CO2 storage projects.
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investigation of oil recovery and co2 storage during secondary and tertiary injection of Carbonated Water in an iranian carbonate oil reservoir
Journal of Petroleum Science and Engineering, 2016Co-Authors: Mahmood Shakiba, Shahab Ayatollahi, Masoud RiaziAbstract:Abstract Gas injection process for more oil recovery and in particular CO 2 injection is well-established method to increment oil recovery from underground oil reservoirs. CO 2 sequestration which takes place during this enhanced oil recovery (EOR) method has positive impact on reducing the greenhouse gas emission which causes global warming. Direct gas injection into depleted oil reservoirs, encounters several shortcomings such as low volumetric sweep efficiency, early breakthrough (BT) and high risk of gas leakage in naturally fractured carbonate oil reservoirs. Carbonated Water injection (CWI) has been recently proposed as an alternative method to alleviate the problems associated with gas injection. In this paper, the results of extensive experimental tests of ultimate oil recovery efficiency as both secondary and tertiary CWI tests and their CO 2 storage capacity for an Iranian carbonate reservoir are presented. Besides, the CWI recovery efficiencies are compared with traditional Water flooding (WF) test. The results showed that higher ultimate oil recovery is achieved when Carbonated Water is injected as secondary technique compared to tertiary process. The results showed 40.54% and 56.74% more oil recovery during tertiary Carbonated Water injection (TCWI) and secondary Water injection (SCWI) compared to the corresponding Water flooding, respectively. However, the CO 2 storage capacities for both TCWI and SCWI cases were almost the same, as it was measured to be more than half of the total delivered CO 2 .
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Theoretical investigation of pore-scale mechanisms of Carbonated Water injection
Journal of Petroleum Science and Engineering, 2010Co-Authors: Masoud Riazi, Mahmoud Jamiolahmady, Mehran SohrabiAbstract:Abstract CO 2 injection is a well-established method for enhanced oil recovery and numerous studies have been dedicated to studying this process at the pore level. An attractive enhanced oil recovery method with much better sweep efficiency, which has received less attention, is Carbonated Water injection. In this work, a mathematical model was developed, which simulates, at pore level, the dynamic process of swelling of an oil ganglion when it comes in direct contact with Carbonated Water or is separated from the CO 2 source by Water layers (indirect contact), a sensitivity analysis of pertinent parameters on the mass transfer process was carried out based on two different evaluation methods. In the first evaluation method, which is beneficial for evaluating the impact of uncertainty of input parameters for simulating the results of an experiment, the time required for the interface to reach a specified position, which was selected as that of a base case, was investigated. In the second evaluation method, which is more independent, the required time for the interface to reach its equilibrium position, which is different for each case under study, was compared with that of the same base case. The impact of some of the pertinent parameters as predicted by the model was linked to results obtained using a new relationship developed based on the dimensional analysis technique. The results suggest practical guidelines on the effect of a Water layer and fluid properties in this multi-physics process.
Shengnan Chen - One of the best experts on this subject based on the ideXlab platform.
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Effects of Operational Parameters on Diffusion Coefficients of CO2 in a Carbonated Water–Oil System
Industrial & Engineering Chemistry Research, 2017Co-Authors: Guanli Shu, Mingzhe Dong, Hassan Hassanzadeh, Shengnan ChenAbstract:Diffusion of carbon dioxide (CO2) in a Carbonated Water–oil system is of great importance for proper design of CO2-based enhanced oil recovery (EOR) processes. We study the effects of operational parameters such as saturation pressure, temperature, and phase volumes on diffusion coefficients of CO2 in a Carbonated Water–oil system. Results show that diffusion coefficients of CO2 in both phases are susceptible to saturation pressure. The greater the saturation pressure, the larger the diffusion coefficients. At a given saturation pressure, diffusion coefficients of CO2 in two phases increase by increasing temperature. Values of the coefficients determined at 40 °C are about twice those determined at 20 °C. The equilibration of the system was found to be much faster at the higher temperature. The results indicate that the predicted diffusion coefficients are insensitive to phase volumes, indicating applicability of the determined diffusion coefficients to simulate the mass transfer in large-scale reservoirs.
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Mass Transfer of CO2 in a Carbonated Water–Oil System at High Pressures
Industrial & Engineering Chemistry Research, 2016Co-Authors: Guanli Shu, Mingzhe Dong, Shengnan Chen, Hassan HassanzadehAbstract:In this paper, CO2 diffusion coefficients in a carbonate Water–oil system are determined by measuring the pressure buildup in the closed Water–oil system experimentally and modeling the pressure change mathematically. The mathematical method of investigating one-dimensional, time-dependent heat conduction in a composite medium is adopted to solve the mass transfer problem between two liquid phases. The model is combined with well-designed trial-and-error method to determine diffusion coefficients of CO2 in both Water and oil phases at the same time. The model considers a moving interface between Carbonated Water and oil as well as variations of interface concentrations of CO2 in these two phases, which more effectively conforms to reality. Results show that the pressure buildup during the diffusion process resulted from the increased density and swelling of the oil phase. The diffusion coefficient of CO2 in the Water phase plays a major role in the interphase mass transfer process.
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Improvement of CO2 EOR performance in Water-wet reservoirs by adding active Carbonated Water
Journal of Petroleum Science and Engineering, 2014Co-Authors: Guanli Shu, Mingzhe Dong, Shengnan Chen, Peng LuoAbstract:Abstract A significant amount of oil is trapped by the continuous Water phase in Water-wet reservoirs during Waterflooding and CO2 Water-alternating-gas (WAG) flooding processes. In tertiary CO2 injection, such a phenomenon may cause part of the residual oil to be inaccessible to the injected CO2 and remain trapped by Water. As a result, the displacement efficiency of the CO2 WAG process is reduced, as is the oil recovery. This paper discusses the experimental investigation of a method of pre-flushing the reservoir using active Carbonated Water (ACW) before a CO2 flood. A total of 10 coreflood tests were conducted to investigate the effects of different injection strategies, slug sizes, and core lengths on the tertiary oil recovery. A comparison of the four laboratory tests with different injection strategies demonstrates that applying the active Carbonated Water as a pre-flush before a CO2 flood is an effective strategy for enhancing the tertiary oil recovery. Oil recovery was increased by 35.5%, compared to 16.6% from injecting CO2 alone. Results of the other seven tests using different slug sizes of active carbonate Water indicate that the optimal slug size of 0.6 pore volume (PV) achieved the maximum improvement in oil recovery of CO2 injection. In addition, a test in a longer core shows the extension of core length does not influence the oil recovery, which indicates the adsorption of surfactant is not significant in this study.
Hassan Hassanzadeh - One of the best experts on this subject based on the ideXlab platform.
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Effects of Operational Parameters on Diffusion Coefficients of CO2 in a Carbonated Water–Oil System
Industrial & Engineering Chemistry Research, 2017Co-Authors: Guanli Shu, Mingzhe Dong, Hassan Hassanzadeh, Shengnan ChenAbstract:Diffusion of carbon dioxide (CO2) in a Carbonated Water–oil system is of great importance for proper design of CO2-based enhanced oil recovery (EOR) processes. We study the effects of operational parameters such as saturation pressure, temperature, and phase volumes on diffusion coefficients of CO2 in a Carbonated Water–oil system. Results show that diffusion coefficients of CO2 in both phases are susceptible to saturation pressure. The greater the saturation pressure, the larger the diffusion coefficients. At a given saturation pressure, diffusion coefficients of CO2 in two phases increase by increasing temperature. Values of the coefficients determined at 40 °C are about twice those determined at 20 °C. The equilibration of the system was found to be much faster at the higher temperature. The results indicate that the predicted diffusion coefficients are insensitive to phase volumes, indicating applicability of the determined diffusion coefficients to simulate the mass transfer in large-scale reservoirs.
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Mass Transfer of CO2 in a Carbonated Water–Oil System at High Pressures
Industrial & Engineering Chemistry Research, 2016Co-Authors: Guanli Shu, Mingzhe Dong, Shengnan Chen, Hassan HassanzadehAbstract:In this paper, CO2 diffusion coefficients in a carbonate Water–oil system are determined by measuring the pressure buildup in the closed Water–oil system experimentally and modeling the pressure change mathematically. The mathematical method of investigating one-dimensional, time-dependent heat conduction in a composite medium is adopted to solve the mass transfer problem between two liquid phases. The model is combined with well-designed trial-and-error method to determine diffusion coefficients of CO2 in both Water and oil phases at the same time. The model considers a moving interface between Carbonated Water and oil as well as variations of interface concentrations of CO2 in these two phases, which more effectively conforms to reality. Results show that the pressure buildup during the diffusion process resulted from the increased density and swelling of the oil phase. The diffusion coefficient of CO2 in the Water phase plays a major role in the interphase mass transfer process.