Abstract:Mobilization of the capillary trapped oil beyond the conventional recovery methods is essential to enhance the oil extraction process and meet the global energy demands. Partially hydrolyzed polyacrylamide (HPAM) is a water-soluble polymer widely used to control the mobility ratio between the injected and displaced fluids to improve the sweep efficiency. However, its viscosifying capacity is substantially affected by the harsh reservoir conditions (high temperature and high salinity conditions). Using equilibr… Show more
“…The ionic composition of the brine solution used in our simulation is reported in Table S3, which represents the salinity of seawater and formation brine. 49,50 A six-layer calcite slab terminated at (104) Miller indices was generated by cleaving the triagonal unit cell by Markgraf and Reeder. 51 The 104 is the most stable facet of calcite.…”
Section: Molecular Dynamics Simulationsmentioning
confidence: 99%
“…The PACKMOL code was used to build the initial coordinates of the molecular systems. The ionic composition of the brine solution used in our simulation is reported in Table S3, which represents the salinity of seawater and formation brine. , …”
Section: Experimental Setup and Proceduresmentioning
In the context of CO 2 geological storage, understanding the interplay of interfacial tension (IFT) and wettability dynamics within the CO 2 −brine−rock system plays a huge role in improving their storage capacity and ensuring their secure containment. Ionic liquids (ILs) emerge as a promising surface-active agent that has the potency to alter the reservoir's wettability more toward the water-wet state, thereby increasing the oil recovery. However, the potential of ILs has remained unexplored for enhancing CO 2 geological storage. Hereby, we assess the effect of ILs on the wettability modification of the sandstone reservoirs by measuring the rock−brine−CO 2 contact angles (CA). In this context, we conducted CA measurements on both the clean and crude oil-aged samples, both with and without ILs, at broad ranges of IL concentrations (0−1000 ppm), temperatures (25− 80 °C), and pressures (14.7−3000 psi). This approach is designed to evaluate the CO 2 storage capacity in both the saline aquifers and oil-depleted sandstone reservoirs. Additionally, we also explored the impact of ILs on the CO 2 −seawater (SW) IFT. Findings indicate that the clean sandstone sample maintained a water-wet nature; however, the IL treatment shifted its wettability more toward a strongly water-wet state. While the oil-wet samples were initially identified to be CO 2 -wet, upon treatment with ILs, they shifted to an intermediate water-wet state. Molecular dynamics (MD) simulations were undertaken to get atomistic insights into the rock wettability changes and the CO 2 −SW interface. MD revealed that CO 2 on a clean sandstone alters the rock surface charge, which induces wettability changes. Such charge development is a result of pH modifications induced by CO 2 that affect the silanol group density. The addition of an IL was found to reduce the effect of CO 2 on the rock surface charge. IL is adsorbed on the rock surface and screens the rock−CO 2 interactions, maintaining the water-wet state. Such wettability alteration is poised to significantly improve CO 2 storage efficiency, thereby reducing the security risks that are associated with it. The finding highlights that enhancing the CO 2 storage efficiency can be greatly improved by preliminarily injecting ILs before CO 2 flooding at a minor concentration. It is worth highlighting that the observed SW−CO 2 IFT changes with ILs are relatively minimal, indicating a favorable condition for capillary trapping. Furthermore, the investigated ILs exhibit exceptional stability, solubility, detectability, scalability, and economic viability; thus, the preinjection of these solutions will make them robust solutions to improve the CO 2 storage potential and containment security at the reservoir conditions.
“…The ionic composition of the brine solution used in our simulation is reported in Table S3, which represents the salinity of seawater and formation brine. 49,50 A six-layer calcite slab terminated at (104) Miller indices was generated by cleaving the triagonal unit cell by Markgraf and Reeder. 51 The 104 is the most stable facet of calcite.…”
Section: Molecular Dynamics Simulationsmentioning
confidence: 99%
“…The PACKMOL code was used to build the initial coordinates of the molecular systems. The ionic composition of the brine solution used in our simulation is reported in Table S3, which represents the salinity of seawater and formation brine. , …”
Section: Experimental Setup and Proceduresmentioning
In the context of CO 2 geological storage, understanding the interplay of interfacial tension (IFT) and wettability dynamics within the CO 2 −brine−rock system plays a huge role in improving their storage capacity and ensuring their secure containment. Ionic liquids (ILs) emerge as a promising surface-active agent that has the potency to alter the reservoir's wettability more toward the water-wet state, thereby increasing the oil recovery. However, the potential of ILs has remained unexplored for enhancing CO 2 geological storage. Hereby, we assess the effect of ILs on the wettability modification of the sandstone reservoirs by measuring the rock−brine−CO 2 contact angles (CA). In this context, we conducted CA measurements on both the clean and crude oil-aged samples, both with and without ILs, at broad ranges of IL concentrations (0−1000 ppm), temperatures (25− 80 °C), and pressures (14.7−3000 psi). This approach is designed to evaluate the CO 2 storage capacity in both the saline aquifers and oil-depleted sandstone reservoirs. Additionally, we also explored the impact of ILs on the CO 2 −seawater (SW) IFT. Findings indicate that the clean sandstone sample maintained a water-wet nature; however, the IL treatment shifted its wettability more toward a strongly water-wet state. While the oil-wet samples were initially identified to be CO 2 -wet, upon treatment with ILs, they shifted to an intermediate water-wet state. Molecular dynamics (MD) simulations were undertaken to get atomistic insights into the rock wettability changes and the CO 2 −SW interface. MD revealed that CO 2 on a clean sandstone alters the rock surface charge, which induces wettability changes. Such charge development is a result of pH modifications induced by CO 2 that affect the silanol group density. The addition of an IL was found to reduce the effect of CO 2 on the rock surface charge. IL is adsorbed on the rock surface and screens the rock−CO 2 interactions, maintaining the water-wet state. Such wettability alteration is poised to significantly improve CO 2 storage efficiency, thereby reducing the security risks that are associated with it. The finding highlights that enhancing the CO 2 storage efficiency can be greatly improved by preliminarily injecting ILs before CO 2 flooding at a minor concentration. It is worth highlighting that the observed SW−CO 2 IFT changes with ILs are relatively minimal, indicating a favorable condition for capillary trapping. Furthermore, the investigated ILs exhibit exceptional stability, solubility, detectability, scalability, and economic viability; thus, the preinjection of these solutions will make them robust solutions to improve the CO 2 storage potential and containment security at the reservoir conditions.
“…Concerning ATBS, a sulfonation degree of around 32 mol% (60 wt%) is typical for most commercial sulfonated polymers, including VHM (32 mol%), SUPERPUSHER SAV55 (35 mol%), and THERMOASSOCIATIF polymers (around 32 mol%). A very stable polymer, SAV10, may have a sulfonation degree higher than 45 mol% 39 . Figure 2 Chemical structures of ( a ) Acrylamido Tertiobutyl Sulfonate (ATBS) and ( b ) N-vinylpyrrolidone (NVP).…”
Section: Polymer Flooding Under Extreme Reservoir Conditionsmentioning
Polymer flooding is a proven chemical Enhanced Oil Recovery (cEOR) method that boosts oil production beyond waterflooding. Thorough theoretical and practical knowledge has been obtained for this technique through numerous experimental, simulation, and field works. According to the conventional belief, this technique improves macroscopic sweep efficiency due to high polymer viscosity by producing moveable oil that remains unswept after secondary recovery. However, recent studies show that in addition to viscosity, polymer viscoelasticity can be effectively utilized to increase oil recovery by mobilizing residual oil and improving microscopic displacement efficiency in addition to macroscopic sweep efficiency. The polymer flooding is frequently implemented in sandstones with limited application in carbonates. This limitation is associated with extreme reservoir conditions, such as high concentrations of monovalent and divalent ions in the formation brine and ultimate reservoir temperatures. Other complications include the high heterogeneity of tight carbonates and their mixed-to-oil wettability. To overcome the challenges related to severe reservoir conditions, novel polymers have been introduced. These new polymers have unique monomers protecting them from chemical and thermal degradations. Monomers, such as NVP (N-vinylpyrrolidone) and ATBS (2-acrylamido-2-methylpropane sulfonic acid), enhance the chemical resistance of polymers against hydrolysis, mitigating the risk of viscosity reduction or precipitation in challenging reservoir conditions. However, the viscoelasticity of these novel polymers and their corresponding impact on microscopic displacement efficiency are not well established and require further investigation in this area. In this study, we comprehensively review recent works on viscoelastic polymer flow under various reservoir conditions, including carbonates and sandstones. In addition, the paper defines various mechanisms underlying incremental oil recovery by viscoelastic polymers and extensively describes the means of controlling and improving their viscoelasticity. Furthermore, the polymer screening studies for harsh reservoir conditions are also included. Finally, the impact of viscoelastic synthetic polymers on oil mobilization, the difficulties faced during this cEOR process, and the list of field applications in carbonates and sandstones can also be found in our work. This paper may serve as a guide for commencing or performing laboratory- and field-scale projects related to viscoelastic polymer flooding.
“…Common approaches include Monte-Carlo 14 and molecular dynamics (MD) at an atomistic level. 15,16 Whilst these atomistic type approaches can clearly provide significant insight, [15][16][17][18] there is a limitation in the scale that can be achieved (i.e. the simulatable length-scale is between Å and nm and time duration up to ms) due to associated computational cost.…”
The availability of accurate liquid phase diagrams are of importance to the formulation industry where it is necessary to formulate for specific physical behaviour to ensure product performance (e.g. to avoid stability issues such as phase separation etc.). It takes significant levels of effort to generate these diagrams experimentally which requires repeating each time a chemical ingredient is replaced. Alternative theoretical and computational methods can speed up turn around and reduce costs. One such technique is to run molecular simulations of the mixtures to sample the phase state and use these to interpolated across to obtain the full phase diagram. Additionally, molecular simulations can provide physical insights, such as topological and behavioural mechanisms, not accessible by other methods. In this work, we present a methodology for efficiently analyzing molecular simulations and elucidating the phase behaviour across a liquid ternary phase diagram using the examples of toluene + methanol + water and xylene + methanol + water. We present atomistic molecular dynamics and coarse-grain dissipative particle dynamics simulations and show the utility of a several metrics to profile the local mass concentrations to determine the solutions phase behaviour.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
