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Mohsen Masihi - One of the best experts on this subject based on the ideXlab platform.
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relative permeability and capillary pressure curves for low salinity Water flooding in sandstone rocks
Journal of Natural Gas Science and Engineering, 2015Co-Authors: Mohammad Javad Shojaei, Mohammad Hossein Ghazanfari, Mohsen MasihiAbstract:Abstract Recently much attention has been paid to the use of low salinity Water (LSW) as an enhanced oil recovery fluid. The change observed in recovery factor during LSW flooding is induced from changes in relative permeability and capillary pressure when different levels of salinity are used. However, a few researchers tried to evaluate how macroscopic flow functions depend on the salinity of the injected Water. To this end, a series of oil displacement by Water was performed on a sandstone rock aged with crude oil in the presence of Connate Water. The capillary pressure and relative permeability curves are evaluated from inverse modeling of the obtained pressure drop and oil production data. Then, the parameters of two capillary pressure and relative permeability models as a function of Water saturation and salinity are determined. The results revealed that the exponents of flow functions as well as residual oil saturation changed linearly with the salt concentration. This showed wettability changed from mixed wet to a Water wet condition. Moreover, the results indicated that the oil recovery enhancement is controlled by wettability alteration to a more Water-wet condition and also IFT reduction.
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effect of small scale flow barriers heterogeneities and Connate Water on displacement efficiency of polymer floods to heavy oil reservoirs
Canadian Journal of Chemical Engineering, 2013Co-Authors: Saber Mohammadi, Mohsen Masihi, Mohammed Hossein Ghazanfari, Shapour VossoughiAbstract:This work concerns a fundamental understanding of how heterogeneities induced by flow barriers and Connate Water affect the displacement efficiency of polymer floods, which has rarely been studied in the available literature. Here, a series of Water/polymer injection experiments to heavy oil performed on five-spot glass micromodels containing randomly distributed shale structures is presented. It has been found that macroscopic efficiency of polymer flooding majorly depends on flow barriers distribution/configuration; shale content and geometrical characteristics; presence of Connate Water and wettability of medium. Microscopic pictures revealed that the main parts of Connate Water were trapped in some pores/throats near and especially behind the shale streaks; also, presence of Connate Water causes a reduction of sweep efficiency due to premature breakthrough of displacing fluid in an oil-wet media. In absence of Connate Water, polymer solution could linger and stick to the pore walls to delay the time for a polymer to channel to the production site. Results of this work disclose requirements for a detailed geologic study of barrier size and distribution for successful design of EOR processes in heterogeneous reservoirs.
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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.
Jianzhong Jiang - One of the best experts on this subject based on the ideXlab platform.
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performances of guerbet alcohol ethoxylates for surfactant polymer flooding free of alkali
Energy & Fuels, 2017Co-Authors: Yuanli Li, Binglei Song, Jianzhong JiangAbstract:Two series of double-chain single-head nonionic surfactants, Guerbet alcohol ethoxylates (CmGA–En; m = 16 and 20, n = 5.7–24.0), were synthesized, and their performances as surfactants for surfactant–polymer (SP) flooding free of alkali were evaluated. The products have relatively low critical micelle concentrations [(6.8 × 10–7)–(1.0 × 10–5 mol/L)] and a wide range of surface tensions at the critical micelle concentration (γcmc) values (30.3–38.0 mN/m) at 25 °C, depending on both the alkyl-chain length and the number of ethylene oxide (EO) units. When used alone, these nonionic surfactants are not efficient for reducing crude oil/Connate Water interfacial tension (IFT), but their binary mixtures with a highly hydrophobic zwitterionic surfactant, didodecylmethyl hydroxylpropyl sulfobetaine (diC12HSB), are very efficient in reducing Daqing crude oil/Connate Water IFTs. Ultralow IFTs can be achieved in a wide total concentration range (0.3–10 mM) at 45 °C, and the low limit (0.3 mM) can be further reduced t...
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New Series of Double-Chain Single-Head Nonionic Surfactants: 1,3-Dialkyl Glyceryl Ether Ethoxylates for Surfactant–Polymer Flooding
2017Co-Authors: Li-min Yan, Binglei Song, Zhenggang Cui, Xiaomei Pei, Jianzhong JiangAbstract:A new series of nonionic surfactants with double hydrocarbon tails and a single polyoxyethylene (POE) chain 1,3-dialkyl glyceryl ether ethoxylates with an alkyl length between diC8 and diC12 and ethylene oxide (EO) number between 3.9 and 25.6 were synthesized and characterized. The correlation of their surfactant–polymer (SP) flooding behavior with the alkyl length and EO number were studied. Although the individual surfactants can be made highly surface-active by matching the alkyl lengths with an appropriate EO number as reflected by the low critical concentration range of 6 × 10–7 to 9 × 10–5 mol/L and γcmc as low as 26.5–30.5 mN/m at 25 °C, they are not good surfactants for SP flooding when used alone since ultralow interfacial tension (IFT) between Daqing crude oil and Connate Water can only be achieved by a few members with short POE chains or hydrophile–lipophile balance (HLB) numbers near 7–8, which are poorly soluble in Water. However, those with long POE chains exhibit excellent synergism in reducing Daqing crude oil/Connate Water IFT by mixing with a highly hydrophobic surfactant, didodecylmethylhydroxylpropyl sulfobetaine (diC12HSB). Ultralow IFT between 10–3 and 10–4 mN/m can be achieved in a wide range of total surfactant concentrations (0.3–10 mM) at 45 °C. The binary mixed systems also possess good resistance against adsorption by Daqing sandstone and the ability to maintain negatively charged surfaces Water-wet over a wide concentration range, as well as a tendency to form crude oil-in-Water (O/W) emulsions, which are all beneficial for high oil recovery in SP flooding. This synergism between nonionic surfactants and the sulfobetaine surfactant may be responsible for the excellent behavior of binary mixtures and the double alkyl chains in nonionic surfactants, which enhance the interaction between the surfactant monolayer and crude oil, making them superior to the conventional nonionic surfactants with a monoalkyl tail. Although the nonionic surfactants with long POE chains and varying alkyl lengths (diC8–diC12) behave similarly, those with diC8 alkyls are generally superior due to their excellent properties and relatively low molar mass (less dosage)
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a new type of sulfobetaine surfactant with double alkyl polyoxyethylene ether chains for enhanced oil recovery
Journal of Surfactants and Detergents, 2016Co-Authors: Peiqian Li, Binglei Song, Jianzhong Jiang, Cheng Yang, Zhijun WangAbstract:A new type of sulfobetaine with double alkyl polyoxyethylene (n) ether chains, dicoconut oil alcohol polyoxethylene (n) ether methylhydroxylpropyl sulfobetaine (diC12–14EnHSB) was synthesized using a commercial nonionic surfactant, coconut oil alcohol polyoxethylene (n) ether, as raw material and its properties as a surfactant for enhanced oil recovery (EOR) in the absence of alkali was studied. The purified product is a mixture of homologues with mainly C12/C12, C12/C14 and C14/C14 alkyl chains and widely distributed EO chains (n = 2.2 on average) with an average molar mass of 742.6 g/mol. The diC12–14E2.2HSB has an improved aqueous solubility at 25 °C compared with didodecylmethylhydroxylpropyl sulfobetaine (diC12HSB), a homologue without an EO chain, and is highly surface active as reflected by its low CMC (4.6 × 10−6 mol/L), high saturated adsorption (6.8 × 10−10 mol/cm2) and small cross sectional area (0.24 nm2/molec.) at the air/Water interface. With a hydrophile–lipophile balance well matched with Daqing crude oil/Connate Water system, the sulfobetaine can reduce Daqing crude oil/Connate Water interfacial tension to ultra-low values at 45 °C in the absence of alkali, and displays a low saturated adsorption at the sandstone/Water interface (0.0024 mmol/g), reduced by 69 and 92 % respectively in comparison with that of the corresponding carboxyl betaine, diC12–14E2.2B and its homologue without an EO chain, didodecylmethylcarboxyl betaine (diC12B). With these excellent properties diC12–14E2.2HSB gives a high tertiary recovery, 18.4 % original oil in place, when mixed with other hydrophobic and hydrophilic sulfobetaines in surfactant-polymer (SP) flooding free of alkali. The insertion of EO chains in combination with the replacement of carboxyl betaine by sulfobetaine is therefore very efficient for improving the properties of the double chain hydrophobic carboxyl betaines as surfactants for SP flooding free of alkali.
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synthesis of didodecylmethylcarboxyl betaine and its application in surfactant polymer flooding
Journal of Surfactants and Detergents, 2012Co-Authors: Zhenggang Cui, Jianzhong Jiang, Xiaomei Pei, Feng WangAbstract:Enhanced crude oil recovery by chemical flooding has been a main measure for postponing the overall decline of crude oil output in China, and surfactant-polymer (SP) flooding may replace alkali-surfactant-polymer flooding in the future for avoiding the undesired effects of using alkali. In this paper the synthesis of a surfactant with a large hydrophobe, didodecylmethylcarboxyl betaine (diC12B), and its adaptability in SP flooding were investigated. The results show that diC12B can be synthesized by reaction of didodecylmethyl amine, a product commercially available, with chloroacetic acid in the presence of NaOH, with a resulting yield as high as 80 wt% under appropriate conditions. With double dodecyl chain diC12B is highly surface active as displayed by its low CMC, 3.7 × 10−6 mol L−1, low γCMC, 27 mNm−1, as well as high adsorption and small cross section area (≤0.25 nm2) at both air/Water and oil/Water interfaces at 25 °C. By mixing with conventional hydrophilic surfactants diC12B can be well dissolved in Daqing Connate Water and reduce the Daqing crude oil/Connate Water interfacial tension to about 10−3 mN m−1 at 45 °C in a wide total surfactant concentration range, from 0.01 to 0.5 wt%. And a tertiary oil recovery, 18 ± 1.5 % OOIP, can been achieved by SP flooding using natural cores without adding any alkaline agent or neutral electrolyte. DiC12B seems thus to be a good surfactant for enhanced oil recovery by SP flooding.
A J Abbas - One of the best experts on this subject based on the ideXlab platform.
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solubility trapping as a potential secondary mechanism for co2 sequestration during enhanced gas recovery by co2 injection in conventional natural gas reservoirs an experimental approach
Journal of Natural Gas Science and Engineering, 2019Co-Authors: Muhammad Kabir Abba, A J Abbas, G G Nasr, Athari Alotaibi, Martin Laurence Burby, Bello Saidu, Salihu M SuleimanAbstract:Abstract This study aims to experimentally investigate the potential of solubility trapping mechanism in increasing CO2 storage during EGR by CO2 injection and sequestration in conventional natural gas reservoirs. A laboratory core flooding process was carried out to simulate EGR on a sandstone core at 0, 5, 10 wt% NaCl formation Water salinity at 1300 psig, 50 °C and 0.3 ml/min injection rate. The results show that CO2 storage capacity was improved significantly when solubility trapping was considered. Lower Connate Water salinities (0 and 5 wt%) showed higher CO2 solubility from IFT measurements. With 10% Connate Water salinity, the highest accumulation of the CO2 in the reservoir was realised with about 63% of the total CO2 injected stored; an indication of improved storage capacity. Therefore, solubility trapping can potentially increase the CO2 storage capacity of the gas reservoir by serving as a secondary trapping mechanism in addition to the primary structural and stratigraphic trapping and improving CH4 recovery.
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Experimental investigation on the impact of Connate Water salinity on dispersion coefficient in consolidated rocks cores during enhanced gas recovery by CO2 injection
Journal of Natural Gas Science and Engineering, 2018Co-Authors: Mk Abba, A J Abbas, Ghasem G. Nasr, Athari Al-othaibi, Abdulkadir MukhtarAbstract:Connate Water salinity is a vital property of the reservoir and its influence on the displacement efficiency cannot be overemphasised. Despite the numerous analytical literatures on the dispersion behaviour of CO2 in CH4 at different parametric conditions, studies have so far been limited to systematic effects of the process while parameters such as Connate Water salinity of the reservoir has not been given much attention and this could redefine the CO2-CH4 interactions in the reservoir. This study aims to experimentally determine the effect of Connate Water salinity on the dispersion coefficient in consolidated porous media under reservoir conditions. A laboratory core flooding experiment depicting the detailed process of the CO2-CH4 displacement using Grey Berea sandstone core sample at a temperature of 50°C and at a pressure of 1300 psig was carried out to determine the optimum injection rate, from 0.2-0.5 ml/min, for the experimentation based on dispersion coefficients and methane recovery in the horizontal orientation. This was established to be 0.3 ml/min. At the same conditions, the effects of Connate Water saturation of 10% and a salinity of 0 (distilled Water), 5, and 10% wt. with a CO2 injection rate of 0.3 ml/min on the dispersion coefficients was investigated. The results from the core flooding process indicated that the dispersion coefficient decreases with increasing salinity, hence the higher the density of the immobile phase (Connate Water) the lower the dispersion of CO2 into CH4. This is a significant finding given that the inclusion of the Connate Water and its salinity have an effect on the mixing of the gases in the core sample and should be given importance and included during simulation studies for field scale applications of Enhanced Gas Recovery (EGR). This is the first experimental investigation into the relationship between the Connate Water salinity and the dispersion coefficient in consolidated porous media. Keywords: Enhanced Gas Recovery; Dispersion Coefficient; Connate Water Salinity; CO2 sequestration
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Enhanced Gas Recovery by CO2 Injection and Sequestration: Effect of Connate Water Salinity on Displacement Efficiency
Abu Dhabi International Petroleum Exhibition & Conference, 2017Co-Authors: Muhammad Kabir Abba, A J Abbas, Ghasem G. NasrAbstract:As natural gas continues to gain widespread usage as a source of cleaner and efficient fossil fuel, while greenhouse gas emission is attracting environmental consequences, the need for a viable method to enhance gas recovery and curtail greenhouse gas emissions, is paramount. The technique of injecting CO2 for Enhanced Gas Recovery (EGR) is deemed one of the efficient methods for simultaneously storing man-made CO2 emissions and improving additional natural gas recovery from depleted gas fields, provided that the gas miscibility in situ (mixing) can be reduced. This can be achieved by a better understanding of the mechanisms of displacement and the factors that affect them, hence providing vital information for further studies aimed at a wider and robust field scale application and establish the economic viability of the process. Connate Water saturation and salinities are vital properties of the reservoir and their influence on the displacement efficiency cannot be overemphasised. This experimental study determines the effect of Connate Water salinity, in sandstone samples, on the displacement efficiency during EGR. This study presents the first novel experimental measurement of dispersion of CO2 in CH4 as a function of salinity in consolidated porous media. A laboratory experiment depicting the detailed process of the CO2-CH4 displacement in sandstone core samples at a temperature range of 30-70°C and at a pressure range of 500-2000 psig, was carried in the investigation, at a CO2 injection rate of 0.25 ml/min to evaluate the displacement efficiency. The findings indicated that salinity of the Connate Water tends to decrease the dispersion of CO2 in CH4 at the stated conditions. This can be attributed to the increase in density of the Connate Water with increase in salinity, which occupies smaller pore channels within the porous medium. Also, grain diameter measurements were carried out from Scanning Electron Microscopy (SEM) images of the porous media using equivalent circle diameters to establish the characteristic length of mixing of the medium.
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.
Abdulkadir Mukhtar - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation on the impact of Connate Water salinity on dispersion coefficient in consolidated rocks cores during enhanced gas recovery by CO2 injection
Journal of Natural Gas Science and Engineering, 2018Co-Authors: Mk Abba, A J Abbas, Ghasem G. Nasr, Athari Al-othaibi, Abdulkadir MukhtarAbstract:Connate Water salinity is a vital property of the reservoir and its influence on the displacement efficiency cannot be overemphasised. Despite the numerous analytical literatures on the dispersion behaviour of CO2 in CH4 at different parametric conditions, studies have so far been limited to systematic effects of the process while parameters such as Connate Water salinity of the reservoir has not been given much attention and this could redefine the CO2-CH4 interactions in the reservoir. This study aims to experimentally determine the effect of Connate Water salinity on the dispersion coefficient in consolidated porous media under reservoir conditions. A laboratory core flooding experiment depicting the detailed process of the CO2-CH4 displacement using Grey Berea sandstone core sample at a temperature of 50°C and at a pressure of 1300 psig was carried out to determine the optimum injection rate, from 0.2-0.5 ml/min, for the experimentation based on dispersion coefficients and methane recovery in the horizontal orientation. This was established to be 0.3 ml/min. At the same conditions, the effects of Connate Water saturation of 10% and a salinity of 0 (distilled Water), 5, and 10% wt. with a CO2 injection rate of 0.3 ml/min on the dispersion coefficients was investigated. The results from the core flooding process indicated that the dispersion coefficient decreases with increasing salinity, hence the higher the density of the immobile phase (Connate Water) the lower the dispersion of CO2 into CH4. This is a significant finding given that the inclusion of the Connate Water and its salinity have an effect on the mixing of the gases in the core sample and should be given importance and included during simulation studies for field scale applications of Enhanced Gas Recovery (EGR). This is the first experimental investigation into the relationship between the Connate Water salinity and the dispersion coefficient in consolidated porous media. Keywords: Enhanced Gas Recovery; Dispersion Coefficient; Connate Water Salinity; CO2 sequestration