Brine pH Research Articles

The Synergic Effect of Brine Salinity and Dispersed Clay Particles on Water-in-Heavy Oil Emulsion: Insight into Asphaltene Structure and Emulsion Stability

Summary The research on enhancing oil recovery in sandstone reservoirs through low-salinity waterflooding (LSWF) has been well-documented, while there have been few studies conducted on the impact of emulsion formation in heavy oil due to the incompatibility between the injected brine, clay particles, and heavy oil components. In this study, we explored the synergic role of asphaltene and clay in the process of LSWF by introducing an innovative and thorough experimental approach. Our findings presented new insights into how LSWF in clay-rich sandstone reservoirs can influence the behavior and properties of the water-in-heavy oil emulsions. In this regard, we contacted the heavy oil and brine (with and without clay) for 20 days at 90°C. Then, the emulsion was centrifuged to separate the oil and brine phases. The oil phase was examined by conducting the viscosity, interfacial tension (IFT), Fourier transform infrared spectroscopy (FTIR), and asphaltene onset point (AOP) precipitation experiments. Significant decreases in viscosity and asphaltene precipitation values were observed when crude oil was exposed to clay solutions, as indicated by viscosity and IP-143 results. Furthermore, the zeta potential of clay particles suspended in various brines was determined to assess the electrostatic aspects of rock-oil interactions. The analysis of the emulsion phase indicated that the emulsion stability in the presence of clay increased because of the improvement of asphaltene contribution in the interface. This trend aligns with the zeta potential measurement results. In addition, after examining the pH and conductivity of aged brine in the presence and absence of clay, it was observed that the clay caused the release of hydrogen ions in the brine and then bonded with the dissolved cations, leading to improvement in the emulsion stability. Ultimately, the asphaltene molecular structure was compared via scanning electron microscopy (SEM) and attenuated total reflection analysis before contact with the brine and after separation from the emulsion phase. The results indicated a decrease in the concentration of aliphatic groups in the molecular structure of the remaining asphaltene following the aging of the oil bulk. These new findings can potentially mitigate unwanted emulsion damage in the LSWF in heavy oil recovery.

Utilisation of Potassium Chloride in the Production of White Brined Cheese: Artificial Neural Network Modeling and Kinetic Models for Predicting Brine and Cheese Properties during Storage

Excessive sodium consumption is a worldwide problem, prompting the industry to develop sodium-reduced products and substitute salts. High sodium consumption is a significant risk factor for high blood pressure, cardiovascular disease and kidney disease. Excessive sodium intake also impairs the immune system in the gastrointestinal tract. Potassium chloride (KCl) is the most commonly used mineral salt due to its similarity to sodium chloride (NaCl), and its consumption has been shown to lower blood pressure when consumed in adequate amounts. The aim of this study was to partially replace NaCl with KCl at levels of 25%, 50% and 75% in the brine used to make white brined cheese. Parameters such as acidity, total dissolved solids, salinity, conductivity, colour, texture and sensory properties were evaluated during a 28-day refrigerated storage period. KCl can replace NaCl by 50%, and no significant differences in physicochemical and sensory parameters were observed during cheese storage compared to the control sample. In addition, the study investigates the use of Artificial Neural Network (ANN) models to predict certain brine and cheese properties. The study successfully developed four different ANN models to accurately predict various properties such as brine pH, cheese colour and hardness over a 28-day storage period.

Selective lithium extraction employing lithium manganese oxide-loaded polymeric membranes at natural brine pH and room temperature

The current technology for lithium extraction from brines is recognized both for its techno-economic disadvantages and its environmental impacts. We have synthesized, characterized, and evaluated particles based on lithium manganese oxide towards selective lithium recovery from complex media. A solid-state synthesis and a hydrothermal method produced sub-micrometre sized particles that showed diameters of 253 nm and 154 nm, respectively, both with very low polydispersity. 23.7 mgLi/gHMO and 30.7 mgLi/gHMO adsorption capacity values were obtained with solid-state synthetic and hydrothermal oxides. The hydrothermally synthesized sub-micrometre sized particles were incorporated into polymeric membranes aiming at the development of a straightforward technological application. Membranes were prepared from polyacrylonitrile and polyethylene-glycol, and the affinity to lithium was once again evaluated. Membranes showed a high adsorption capacity for lithium (32.7 mgLi/gHMO) with almost identical kinetics and cyclability as the free particles in solution. An excellent selectivity for lithium was confirmed in experiments with a natural lithium-rich brine from the Lithium Triangle. All adsorption experiments were performed at neutral pH and room temperature. An undeniable advantage of membranes vs. sub-micrometre sized particles is that the former do not require centrifugation after successful adsorption/desorption. These three characteristics are fundamental in the perspective of technology scale-up to minimize operational costs.

IMPLICATIONS OF STABILIZERS USED IN BRINE OF SOFT WHITE CHEESE ON THE AROMA PROFILE OF CHEESES

This paper describes the compositional characterization of cheese brine and aroma profile of Soft White cheese which contains different stabilizers such as sodium caseinate, carrageenan and guar gum in the brine solutions. During the 60-day storage period, pH, titration acidity, dry matter, fat, salt and protein amounts of cheese brines were analyzed. The aroma profile of the cheese samples was examined by gas chromatography–mass spectrometry using a solid-phase microextraction technique and the proportional distribution of volatile compounds was revealed. The stabilizers in the brine increased the dry matter content in the cheese mass by binding the water and reduced salt penetration into the cheese mass. A total of 23 aromatic compounds were identified including 4 aldehydes, 5 alcohols, 4 esters, 1 ether, 5 hydrocarbons, 2 ketones and 2 organic acids in cheeses. Carrageenan and guar gum were found more effective than sodium caseinate in terms of flavor retention.

Thermodynamic Properties of a Gas–Liquid–Solid System during the CO2 Geological Storage and Utilization Process: A Review

Emission reduction in the main greenhouse gas, CO2, can be achieved efficiently via CO2 geological storage and utilization (CCUS) methods such as the CO2 enhanced oil/water/gas recovery technique, which is considered to be an important strategic technology for the low-carbon development of China’s coal-based energy system. During the CCUS, the thermodynamic properties of the CO2–water–rock system, such as the interfacial tension (IFT) and wettability of the caprock, determine the injectability, sealing capacity, and safety of this scheme. Thus, researchers have been conducting laboratory experiments and modeling work on the interfacial tension between CO2 and the water/brine, wettability of caprocks, the solubility of gas–liquid binary systems, and the pH of CO2-saturated brine under reservoir temperature and pressure conditions. In this study, the literature related to the thermodynamic properties of the CO2–water–rock system is reviewed, and the main findings of previous studies are listed and discussed thoroughly. It is concluded that limited research is available on the pH of gas-saturated aqueous solutions under CO2 saline aquifer storage conditions, and less emphasis has been given to the wettability of the CO2–water/brine–rock system. Thus, further laboratory and modeling research on the wettability alternations of caprock in terms of molecular dynamics is required to simulate this phenomenon at the molecular level. Moreover, simplified IFT and solubility prediction models with thermodynamic significance and high integrity need to be developed. Furthermore, interaction mechanisms coupling with multi-factors associated with the gas–liquid–solid interface properties and the dissolution and acidification process need to be explored in future work.

A novel oil/brine surface complexation model: Capturing the dynamic nature of the interface using IFT

The electrical properties of the oil/brine interface play a principal role in wettability alteration during low salinity/water flooding. There are few existing surface complexation models (SCMs) for the oil/brine interface. Similar to the mineral surface, all models assume that the surface site density of oil/brine is always constant. Assessment of the existing models shows that they ignore the dynamic nature of the crude oil/brine interface and fail to capture experimentally measured ζ potentials appropriately. The current study proposes a novel diffuse layer SCM considering the interfacial concentration of surface carboxylic acid as a function of brine pH, salinity, and composition. The oil/brine interfacial tension (IFT) was utilized to describe the change in the interfacial concentration of > COOH sites vs. pH and ionic strength. The developed model matches the experimental data of the literature far better than previous models successfully. Based on the model, Na+, Cl-, and SO42- cannot be adsorbed on the oil/brine interface, however; the role of these ions in the electrical behavior of crude oil/brine is only to affect the interfacial concentration of > COOH. The novel model surpasses the previous model at high and low pH conditions. At a high pH range, due to the significant transport of acid groups to the interface, the oil surface becomes more negatively charged, which was accurately captured by the proposed model (while the previous models are malfunctioning at high pH conditions). Assuming maximum > COOH density at the whole pH range, previous models use a high > NH density to compensate for the extra negative surface charge due to > COOH dissociation. Therefore, these models overestimate the zeta potential significantly at low pH conditions, where > NH protonation is the dominant reaction. One of the main features of the developed model in this study is to predict a critical salinity for the extremum of zeta potential. All previous models state that salinity reduction must result in a decrease in the zeta potential. These models cannot capture the observed rise in zeta potential with further brine dilution after a specified salinity. However, the presented model of this study could predict the increase in the zeta potential at lower salinities.

Pickling as a Preservation Technique for Solanum aethiopicum; An Edible Green Leafy Vegetable

Solanum aethiopicum is a nutrient rich green leafy vegetable whose utilisation is limited by its short shelf life. Although refrigeration and freezing are effective methods to preserve vegetables, these methods may not be available and affordable in resource-limited settings. A viable alternative is pickling, which is a cost effective and easy to apply method. In this study, nakati leaves were fermented in brine with 3% dry salt and 2% sugar at 25°C for 14 days. The fermentation was monitored at intervals by enumerating lactic acid bacteria (LAB), coliforms and fungi as well as measuring the brine pH. Sensory evaluation (n=30) was carried out to assess the acceptability of the vegetables. Shelf stability was evaluated for three weeks. The results showed that lactic acid bacteria increased significantly (P < .001) from 2.06 log cfu/ml to 8.2 log cfu/ml during fermentation. Coliforms and fungi reduced from 5.5 log cfu/ml and 1.5 log cfu/ml to undetectable levels within 8 and 6 days of fermentation, respectively. The brine pH decreased from 5.87 at day 0 to 3.35 after 14 days of fermentation (P < .001). Pickled nakati had lower consumer acceptability scores (P < .001) than fresh nakati. The nakati remained stable during the three weeks of storage. Therefore, pickling offers a potentially viable preservation method that can be adopted for green leafy vegetables.

Effect of backfilled stone/brine media on the long‐term free corrosion and electrochemical performance of an aluminum sacrificial anode

AbstractAn Al–Zn–In–Si–Sn–Ti sacrificial anode, utilized to protect steel shells of subsea‐immersed tunnels, works in a backfilled stone (6–10 mm)/brine (40 Ω cm) media (125 Ω cm). This paper investigated its impact on the anode's long‐term free corrosion and electrochemical performance. After prolonged free corrosion, the anode's general corrosion rate is minimal. Although its capacity (Q) and current efficiency (η) increase slightly, it shows a nonuniform dissolution state. Over a long‐term working period, a significant amount of Al(OH)3 deposits and diffuses between the backfilled stone toward the cathode surface, creating distinct stone impressions and a thick product layer. These effects considerably increase the media ρ around the anode and continuously decrease the brine's pH, decreasing Q and η values and output currents. Nonetheless, the current distribution within the media gradually becomes uniform with time, resulting in a homogeneous potential distribution along the cathode.

Low-temperature geochemistry of B in a hypersaline basin of Central Andes: Insights from mineralogy and isotopic analysis (δ11B and 87Sr/86Sr)

The dynamics of B isotopes in the hypersaline Olaroz basin located in the Central Andes, was characterized by means of chemical and isotopic analysis (δ11B and 87Sr/86Sr) of brines, warm springs, rivers, evaporites, and regional rocks. The mineralogical composition of evaporites was determined by XRPD and SEM/EDS, while the fractionation of B isotopes was simulated using a batch-type model. The results revealed that the alteration of ignimbrite rocks in the arid climate conditions of the study area is triggered by the circulation of thermal waters in the main tributary's catchments, and generates solutions that preserve the isotopic signature of the basin rocks. The B-rich leachates are transported downflow by runoff and once in the salt flat, the B concentration increases due to evaporation. Modeling results suggest that fractionation occurs during infiltration of water in the salt flat nucleus, by ulexite precipitation. However, shifts of δ11B values between brines and evaporites are low because the trigonal soluble B species, which concentrates the heavier B isotope, predominates at the neutral pH of brines, and is incorporated into the ulexite lattice in a lower proportion than the tetrahedral species (ratio B(OH)3/B(OH)4− = 2/3). In arid and cold environments such as those of the Altiplano-Puna region, B isotopes are weak proxies of weathering because denudation regimes of the weathering-limited kind result in nearly negligible fractionation of B isotopes by adsorption or co-precipitation onto the solid products of alteration.

Microbial-mediated Changes during the Brine–Shale–Microorganism Interaction Process

Exogenous microorganisms are introduced into the shale gas reservoir during hydraulic fracturing, but the microbial-mediated changes in the process are yet unclear. Here, a brine–shale–microorganism interaction was simulated in the laboratory for 150 days. Biogenic methane was generated rapidly in 0–16 days, then slowly in 16–40 days and stopped after 40 days, accompanying by brine alkalization. Formation trend of biogenic methane may be independent of the substrate type under the same conditions. Biofilms accelerated mineral dissolution and facilitated secondary mineral formation. Microbial action enhanced the complexity and heterogeneity of macropore structure. Archaeal community structure changed little, while bacterial community structure altered significantly, with bacterial diversity decreasing. Predominant Proteobacteria in the early stage almost disappeared, while Firmicutes, Bacteroides and Desulfobacterota gradually increased. Firmicutes showed a transfer tendency from brine to biofilms. Proteiniphilum and Petrimonas were mainly distributed in brine, whereas Sedimentibacter and Clostridium_sensu_stricto_13 dominated in biofilms. Desulfovibrio was highly distributed in both brine and biofilms. Loss of microbial diversity and the self-assembly of symbiotic microorganisms with cooperation and competition occurred in response to the changes in the shale environment, which also affected methane production, brine pH, and both mineral composition and pore structure.

Effect of dense phase carbon dioxide treatment on the flavor, texture, and quality changes in new-paocai

This study investigated the effect of dense phase carbon dioxide (DPCD) treatment on the organoleptic properties of new-paocai. Optimal DPCD treatment (25 MPa/40 °C/40 min) was determined by conducting single-factor and orthogonal experiments with the sensory, bactericidal, and electronic eye evaluations. DPCD treatment (25 MPa/40 °C/40 min) did not significantly affect the nitrite, pH, total acid, and organic acid of the new-paocai brine, and the texture of the radish slices did not display substantial changes. Gas chromatography-mass spectrometry (GC–MS) was employed to characterize the new-paocai brine flavor, revealing 63 and 60 respective flavor compounds with and without DPCD treatment. In addition, DPCD treatment significantly reduced the total organic volatile compound content in the paocai from 48.182 μg/mL to 35.952 μg/mL, DPCD has a great influence on volatile flavor substances. The electronic nose (E-nose) effectively distinguished the flavor differences in the new-paocai brine with and without DPCD treatment. This study combined new food processing technology with traditional food production, could provide a new idea for pickle production technology.

Use of Ca-containing industrial waste brine for CO2 sequestration and recovery of NaCl and Na2SO4

Carbon dioxide (CO2) capture and sequestration play a vital role in global warming and climate change. The objective of this study was to use Ca-containing industrial waste brine for CO2 sequestration and recovery of NaCl and Na2SO4. The following operating parameters were investigated: pH, NaCl concentration, CO2 injection time, CO2 inflow rate, and temperature. The φ-pH diagrams of the Ca–Mg–CO32−–H2O system revealed that the maximum CO2 dissolution efficiency in brine occurred at pH 10.7–14.0. The decalcification efficiency reached 99.0% at the optimal conditions, which were a brine pH of 11.5, a CO2 injection time of 30 min, a CO2 injection velocity of 1.5 L/min, a temperature of 35 °C, and a stirrer speed of 300 rpm. The CO2 capture capacity of Ca-containing industrial waste brine was about 1.29 kg CO2 / m3 Ca-containing waste brine. The sediments produced in the CO2 sequestration process are composed of calcite, which is thermodynamically stable and has economic value. Na2SO4 and NaCl crystals with a narrow size distribution and good anti-caking properties were produced from the refined brine using five-effect evaporation crystallization. These observations provide further understanding and guidance for CO2 capture and the utilization of high salinity wastewater.

The mechanistic investigation on the effect of the crude oil /brine interaction on the interface properties: A study on asphaltene structure

• The Asphaltene molecular Structure was determined by ATR and EDAX analysis. • the Asphaltene adsorption rate at the interface highly depends on the brine salinity. • compaction of the Asphaltene molecules Structure significantly affects the adsorption behavior of the Asphaltene. • The concentration of Asphaltene fraction in the crude oil has a key role in fluid–fluid interaction. • Asphaltene molecules accumulate at the oil-brine interface and perform the Asphaltene-ion-bound with the dissolved ions. Despite many attempts to study the interaction of fluids in low-salinity flooding, they do not examine the principles of interphasic transition phenomena. This study aims to provide a new understanding of liquid–liquid interactions during the low-salinity water interaction through a series of experiments on the oil, emulsion, and aqueous phase. Three samples of crude oils with different asphaltene concentrations and structures with known physical properties are in contact with different solutions. The brine pH, conductivity, and crude oil viscosity experiments before and after contacting the oil with brine showed that the heteroatom concentration and compaction of crude oil asphaltene fraction and the brine salinity affect the rate of the migration of crude oil polar component toward the interface. Moreover, the IFT measurement illustrated that interface interactions are affected by several parameters such as dissolved ion type, the concentration of the brine, and the concentration of the polar components in crude oil. The solubility of crude oil polar species such as naphthenic acids in the brine does not always increase by decreasing the salinity of the aqueous phase. To verify this important finding, UV–Vis spectroscopy and FTIR were performed on the brine and crude oils before and after in contact with each other.

Optimization of NaOH–Na2CO3 brine purification method: From laboratory experiments to industrial application

The NaOH–Na2CO3 brine purification method is an efficient method to prevent the scaling caused by scale-forming ions (Ca2+, Mg2+, and CO32–) in evaporation systems. Because of high CO32− residual concentration and large reagent consumption during brine purification, the thermodynamics of the deposition reaction of Ca2+ and Mg2+ was calculated using thermodynamic calculation software. The results show that the removal efficiencies of Ca2+ and Mg2+ can be improved by increasing the pH value. The experimental results show that the brine pH increased from 10.6 to 11.6 when the alkali solution and raw brine were added simultaneously, increasing the removal efficiency of Ca2+ and Mg2+. The residual total concentration of Ca2+ and Mg2+, CO32– concentration at the optimal dosage of 1.30 g/L Na2CO3 and 0.25 g/L NaOH is 13.9 mg/L and 135.0 mg/L, respectively. The deposition reaction efficiency of Na2CO3 and Ca2+ is improved, and the Na2CO3 consumption is reduced by increasing the NaOH dosage. Moreover, the HCO3– in raw brine can be transformed into CO32–, increasing the CO32– production and rate of CaCO3 deposition reaction. In the industrial production, the average removal efficiency of Ca2+ and Mg2+ is 98.5% and 99.6%, respectively; the residual CO32– concentration is reduced from 231.2 mg/L to 117.3 mg/L. The experiments and economic feasibility analysis results show that the optimized NaOH–Na2CO3 brine purification method not only effectively controls the concentration of Ca2+ and Mg2+ in the refined brine, but also reduces the residual CO32– concentration and reagent consumption, thus effectively preventing the scaling of evaporation system.

Geochemical modeling of CO2 injection and gypsum precipitation at the Ketzin CO2 storage site

Gypsum crystals are found at the well perforation of observation well Ktzi 202 of the test site for CO2 storage at Ketzin, Germany. XRD analysis confirms pure gypsum. Fluid samples before and after CO2 injection are analyzed. Geochemical modeling is conducted to identify the mechanisms that lead to gypsum formation. The modeling is carried out with PHREEQC and Pitzer database due to the high salinity of up to 5 mol per kg water. Due to their significantly higher reactivity compared to other minerals like silicates, calcite, dolomite, magnesite, gypsum, anhydrite, and halite are considered as primary mineral phases for matching the observed brine compositions in our simulations. Calcite, dolomite, and gypsum are close to saturation before and after CO2 injection. Dolomite shows the highest reactivity and mainly contributes to buffering the brine pH that initially decreased due to CO2 injection. The contribution of calcite to the pH-buffering is only minor. Gypsum and anhydrite are no geochemically active minerals before injection. After CO2 injection, gypsum precipitation may occur by two mechanisms: (i) dissociation of CO2 decreases activity of water and, therefore, increases the saturation of all minerals and (ii) dolomite dissolution due to pH-buffering releases Ca2+ ions into solution and shifts the mass action to gypsum. Gypsum precipitation decreases with increasing temperature but increases with increasing partial CO2 pressure. Our calculations show that calcium sulfate precipitation increases by a factor of 5 to a depth of 2000 m when Ketzin pressure and temperature are extrapolated. In general, gypsum precipitation constitutes a potential clogging hazard during CO2 storage and could negatively impact safe site operation. In the presented Ketzin example, this threat is only minor since the total amount of gypsum precipitation is relatively small.

Investigation of Brine pH Effect on the Rheological and Viscoelastic Properties of HPAM Polymer for an Optimized Enhanced Oil Recovery Design.

A novel approach to improve viscous and viscoelastic properties by exploiting the pH and salinity sensitivity of HPAM polymer is proposed in this paper. Polymer flooding is a well-developed and effective enhanced oil recovery technique. The design of the makeup brine is one of the most critical phases of a polymer flood project, since the brine composition, salinity, and pH directly influence the polymer viscosity and viscoelasticity. However, the viscoelastic properties of hydrolyzed polyacrylamide polymers have not been given much consideration during the design phase of polymer flood projects. Our experimental study focuses on the optimization of the makeup water design for polymer flooding by evaluating the optimum solution salinity and pH for better stability and improved viscoelastic behavior of the polymer. Initially, the brine salinity and ionic composition is adjusted and then hydrolyzed polyacrylamide (HPAM) polymer solutions of varying pH are prepared using the adjusted brine. Rheological experiments are conducted over a temperature range of 25–80 °C and at different aging times. Polymer thermal degradation as a function of pH is assessed by examining the solutions at 80 °C for 1 week. Amplitude sweep and frequency sweep tests are performed to determine the viscoelastic properties such as storage modulus, loss modulus, and relaxation time. A 15–40% increase in the polymer solution viscosity and a 20 times increase in relaxation time is observed in the pH range of 8–10 in comparison to the neutral solution. This can be attributed to the low-salinity ion-adjusted environment of the makeup brine and further hydrolysis and increased repulsion of polymer chains in an alkaline environment. These results indicate that the viscoelastic properties of a polymer are tunable and a basic pH is favorable for better synergy between the brine and the polymer. Alkaline low-salinity polymer solutions have exhibited 60% higher thermal stability in comparison to acidic solutions and thus can be successfully applied in high-temperature reservoirs. The results of this study show that polymer solutions with an optimum pH in the basic range exhibit a higher viscoelastic character and an increased resistance toward thermal degradation. Hence, the polymer solution salinity, ionic composition, and pH should be adjusted to obtain maximum oil recovery by the polymer flooding method. Finally, this study shows that more effective polymer solutions can be prepared by adjusting the pH and designing a low-salinity water/polymer recipe to get the additional benefit of polymer viscoelasticity. The optimized low-salinity alkaline conditions can reduce the residual oil saturation by stronger viscous and viscoelastic forces developed by more viscous polymers. The findings of this study can be employed to design an optimum polymer recipe by tuning the brine pH and salinity for maximum incremental oil recovery, particularly in high-temperature and high-salinity formations.

Predicting naphthenate precipitation and evaluating the effect of ionic liquids on its deposition

Naphthenic acids that are naturally carboxylic compounds contained in heavy crude oil are the main source of corrosion and blockage in a crude oil pipeline. The blockage is due to the formation of naphthenate deposits through a reaction of naphthenic acid with metal ions present in the crude oil. In the present study, model oil is used to evaluate the effect of water cut in the range of 10%–90%, brine pH in the range of 6–10, Ca2+ concentration in the range of 0.5%–2.5% and temperature in the range of 30 °C–60 °C towards naphthenate deposition with the aid of response surface methodology. Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) were used to evaluate the structure of the naphthenic acids used. Results show that Ca2+ concentration contributes mostly to the naphthenate deposition, followed by brine pH, water cut and temperature. Two mathematical models were developed to predict the final pH of the oil-brine system and the mass of precipitates with average relative errors (AREs) of 0.0328 and 0.0325 respectively. The effects of two ionic liquids (ILs), 1-ethyl-3-methylimidazolium chloride (EMIM-Cl) and 1-butyl-3-methylimidazolium chloride (BMIM-Cl), on naphthenates precipitation, were also evaluated. Analysis showed that both ILs can reduce the amount of naphthenate deposited, with the BMIM-Cl showing better performance than the EMIM-Cl.

Effectiveness and Isotherm Models of Lewatit Monoplus S-108 on Lithium Adsorption Process from Bledug Kuwu Brine with Continuous Flow

Sorption of a series of alkali metals (Ca, Mg, Li, and K) from Bledug Kuwu’s Brine into Lewatit MonoPlus S-108 resins has been studied. Bledug Kuwu’s Brine comprised 15.11 ppm Li, 179.91 ppm K, 72.01 ppm Ca, and 29.76 ppm Mg. The adsorption was carried out by varying pH of brine (4, 6, 8, and 10) and contact time (1, 2, and 4 hours) with continuous flow in column test at room temperature. The result showed the quantity adsorbate in outer resin: K>Li>Ca>Mg in all conditions, which is 0.038–0.043 mmol/g lithium, 0.087–0.09 mmol/g potassium, 0.031–0.035 mmol/g calcium, and 0.023–0.024 mmol/g magnesium into outer resin surface. The selectivity factor to lithium followed Mg/Li > K/Li> Ca/Li in all conditions. Contact time variable provided high lithium separation after the adsorption process for 2–3 hours, while pH had little effect. FTIR results affirm that resin was changed at new peaks M-O-M at low wavenumber with polystyrene crosslinked-divinylbenzene matrix and contains the sulfonic type. The results obtained from ICP were fitted to isotherm models in ion exchange, as follows: Langmuir, Freundlich, Temkin, and Dubinin-Radushkevic models. The best model of lithium adsorption into Lewatit S-108 is represented by Freundlich and Temkin Model (R2 ≥ 0.82) with 1.0056 mg/g of adsorption capacity (Kf) and 64.885 J/mol of heat process of sorption.

Effect of temperature on the pH of water flood effluents and irreducible water saturation: A study with reference to the Barail sandstone outcrop of the upper Assam Basin

Low salinity water flooding (LSWF) is a promising strategy for improving oil recovery in sandstone reservoirs, and recent studies have shown that the recovery with low salinity water injection is a function of not only the salinity and ionic composition but also of the pH of injected brine, temperature, and the combined effect of both on the wetting properties of the clay mineral surfaces. Following brine flooding, the initial wettability of sandstone rock surfaces existed when crude oil, formation water (FW), and rock surface interaction were in chemical equilibrium at reservoir condition changes based on brine pH, salinity, temperature, and clay mineralogy. This study proposes pH, core flood temperature, and irreducible water saturation as key parameters in inducing wettability changes in the sandstone porous media. In the present work, the sandstone cores were subjected to flooding at temperatures of 70 °C, 85 °C, and 105 °C and measured the pH of the discharge effluents and initial or irreducible water saturation with respect to varying temperatures. This paper investigates the rise of the pH gradient and irreducible water saturation, Swir with respect to LS flooding, at increasing temperatures using a Barail sandstone core. The key results include the following:The pH of the flood effluents increases with increasing core flood temperature, which indicates a shifting of the existing wetting state of the rock.The combined effects of increasing pH and initial or irreducible water saturation pertaining to low salinity flooding at progressively increasing temperatures result in increasing water wettability of the sandstone rock. Increasing flooding temperatures cause an increase in Swir, which follows a linear relationship.The findings of the paper highlight the link of increasing pH and irreducible water saturation with the water wetting properties of the sandstone reservoir rock and hence the fluid flow or the oil–water relative permeability behaviour. This paper proposes that increased irreducible water saturation and pH of water flood effluents are connected to increasing water wetness in a sandstone rock as a function of elevated temperatures. As adequate work and consensus on the potential effects of temperature on wettability alteration under low salinity water flooding is still lacking, the current work in relation to the Barail sandstone of the upper Assam basin could be a novel reference for understanding of the importance of temperature dependent wettability alteration behaviour in sandstone cores. The findings of this study can assist in the formation of a novel approach towards considering the increasing irreducible water saturation and pH of the brine effluent as an effect of alternatively injection of low salinity water at elevated temperatures on sandstone porous rock.

Positive Zeta Potential in Sandstones Saturated With Natural Saline Brine

AbstractIt is widely accepted that the zeta potential in natural sandstones is negative in the brine pH and compositions found in the subsurface. The zeta potential is a measure of the electrical potential at a mineral surface. We report new measurements of the zeta potential using a saline natural brine rich in divalent ions. The sandstone samples were quartz dominated but some also contained dolomite, siderite, and clay minerals. The quartz‐dominated sandstones showed behavior consistent with earlier studies, but the dolomite‐ and siderite‐bearing samples returned positive zeta potentials. We suggest that this is caused by a positive zeta potential on dolomite and siderite mineral surfaces, adsorption of divalent ions onto quartz mineral surfaces, and/or ion exchange with clay minerals. The results have broad implications for the zeta potential of natural sandstones, because the magnitude and polarity of the zeta potential impact geophysical monitoring and the transport of the charged contaminants.