Showing papers on "Brine published in 2016"

Nonmonotonic Elasticity of the Crude Oil–Brine Interface in Relation to Improved Oil Recovery

Abstract: Injection of optimized chemistry water in enhanced oil recovery (EOR) has gained much interest in the past few years. Crude oil–water interfaces can have a viscoelastic character affected by the adsorption of amphiphilic molecules. The brine concentration as well as surfactants may strongly affect the fluid–fluid interfacial viscoelasticity. In this work we investigate interfacial viscoelasticity of two different oils in terms of brine concentration and a nonionic surfactant. We correlate these measurements with oil recovery in a glass-etched flow microchannel. Interfacial viscoelasticity develops relatively fast in both oils, stabilizing at about 48 h. The interfaces are found to be more elastic than viscous. The interfacial elastic (G′) and viscous (G″) moduli increase as the salt concentration decreases until a maximum in viscoelasticity is observed around 0.01 wt % of salt. Monovalent (Na+) and divalent (Mg2+) cations are used to investigate the effect of ion type; no difference is observed at low sal...

Imaging of oil layers, curvature and contact angle in a mixed-wet and a water-wet carbonate rock

Abstract: We have investigated the effect of wettability of carbonate rocks on the morphologies of remaining oil after sequential oil and brine injection in a capillary-dominated flow regime at elevated pressure. The wettability of Ketton limestone was altered in situ using an oil phase doped with fatty acid which produced mixed-wet conditions (the contact angle where oil contacted the solid surface, measured directly from the images, θ=180°, while brine-filled regions remained water-wet), whereas the untreated rock (without doped oil) was weakly water-wet (θ=47 ± 9°). Using X-ray micro-tomography, we show that the brine displaces oil in larger pores during brine injection in the mixed-wet system, leaving oil layers in the pore corners or sandwiched between two brine interfaces. These oil layers, with an average thickness of 47 ± 17 µm, may provide a conductive flow path for slow oil drainage. In contrast, the oil fragments into isolated oil clusters/ganglia during brine injection under water-wet conditions. Although the remaining oil saturation in a water-wet system is about a factor of two larger than that obtained in the mixed-wet rock, the measured brine-oil interfacial area of the disconnected ganglia is a factor of three smaller than that of oil layers.

Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

Abstract: There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

Phase diagrams and thermochemical modeling of salt lake brine systems. II. NaCl+H2O, KCl+H2O, MgCl2+H2O and CaCl2+H2O systems

Abstract: This study is part of a series of studies on the development of a multi-temperature thermodynamically consistent model for salt lake brine systems. Under the comprehensive thermodynamic framework proposed in our previous study, the thermodynamic properties of the binary systems (i.e., NaCl+H2O, KCl+H2O, MgCl2+H2O and CaCl2+H2O) are simulated by the Pitzer–Simonson–Clegg (PSC) model. Various thermodynamic properties (i.e., water activity, osmotic coefficient, mean ionic activity coefficient, enthalpy of dilution and solution, relative apparent molar enthalpy, heat capacity of aqueous phase and solid phases) are collected and fitted to the model equations. The thermodynamic properties of these systems are reproduced or predicted by the obtained model parameters. Comparison to the experimental or model values in the literature suggests that the model parameters determined in this study can describe all of the thermodynamic and phase equilibria properties over wide temperature and concentration ranges. This modeling study of binary systems provides a solid basis for property predictions of salt lake brines under complicated conditions.

Membrane crystallization for salts recovery from brine—an experimental and theoretical analysis

Abstract: Integration of innovative membrane processes such as membrane distillation (MD) and membrane crystallization (MCr) with conventional pressure-driven operations provide interesting gateways to recover water and minerals from brine at cost competitive with traditional techniques and with improved quality of the salts extracted. Membrane development is one of the most important factors for future progress and commercialization of MD and MCr, thus, in this study, the performance of different poly(vinylidene fluoride) membranes have been tested for water production from (1) NaCl solutions, (2) synthetic sea water, and (3) brine. The utilized membranes have also proved their stability in treatment of saturated solutions for the recovery of high-quality epsomite crystals. In desalination, MD and MCr provide, besides water recovery factors above 90%, the possibility to recover minerals from brine that can partly contribute to the existing mineral extraction industry. This study aims also to give an outloo...

Measurements and Modeling of Interfacial Tension for CO2/CH4/Brine Systems under Reservoir Conditions

Abstract: Supercritical CO2 injection is a promising way to hydraulically fracture tight/shale gas formations as well as enhance gas recovery from these formations. Understanding of phase behavior and interfacial tension (IFT) of CO2/CH4/brine (NaCl) systems is important, because they affect the performance of such a process in tight/shale gas formations. In this study, we employ the axisymmetric drop shape analysis (ADSA) method to measure the IFT between CO2/CH4 mixtures and brine over the temperature range from 77.0 to 257.0 °F and the pressure range from 15 to 5027 psia. Test results show that the presence of CO2 decreases the IFT of CH4/H2O or CH4/brine (NaCl) systems, while the degree of reduction depends on the molar fraction of CO2 in the gas mixture. Salinity tends to cause an increase in IFT of CO2/CH4/brine (NaCl) systems; a higher salinity leads to an increased IFT for a given system. On the basis of the Parachor model (Weinaug and Katz J. Ind. Eng. Chem. 1943, 35, 239) and Firoozabadi’s model (Firoozab...

Metal-rich fluid inclusions provide new insights into unconformity-related U deposits (Athabasca Basin and Basement, Canada)

Abstract: The Paleoproterozoic Athabasca Basin (Canada) hosts numerous giant unconformity-related uranium deposits. The scope of this study is to establish the pressure, temperature, and composition (P-T-X conditions) of the brines that circulated at the base of the Athabasca Basin and in its crystalline basement before, during and after UO2 deposition. These brines are commonly sampled as fluid inclusions in quartz- and dolomite-cementing veins and breccias associated with alteration and U mineralization. Microthermometry and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data from five deposits (Rabbit Lake, P-Patch, Eagle Point, Millennium, and Shea Creek) complement previously published data for the McArthur River deposit. In all of the deposits investigated, fluid inclusion salinity is between 25 and 40 wt.% NaCl equiv., with compositions displaying a continuum between a “NaCl-rich brine” end-member (Cl > Na > Ca > Mg > K) and a “CaCl2-rich brine” end-member (Cl > Ca ≈ Mg > Na > K). The CaCl2-rich brine has the highest salinity and shows evidence for halite saturation at the time of trapping. The continuum of compositions between the NaCl-rich brine and the CaCl2-rich brine end-members combined with P-T reconstructions suggest anisothermal mixing of the two brines (NaCl-rich brine, 180 ± 30 °C and 800 ± 400 bars; CaCl2-rich brine, 120 ± 30 °C and 600 ± 300 bars) that occurred under fluctuating pressure conditions (hydrostatic to supra-hydrostatic). However, because the two brines were U bearing and therefore oxidized, brine mixing was probably not the driving force for UO2 deposition. Several scenarios are put forward to account for the Cl-Na-Ca-Mg-K composition of the brines, involving combinations of seawater evaporation, halite dissolution, mixing with a halite-dissolution brine, Mg/Ca exchange by dolomitization, Na/Ca exchange by albitization of plagioclase, Na/K exchange by albitization of K-feldspar, and Mg loss by Mg-rich alteration. Finally, the metal concentrations in the NaCl-rich and CaCl2-rich brines are among the highest recorded compared to present-day sedimentary formation waters and fluid inclusions from basin-hosted base metal deposits (up to 600 ppm U, 3000 ppm Mn, 4000 ppm Zn, 6000 ppm Cu, 8000 ppm Pb, and 10,000 ppm Fe). The CaCl2-rich brine carries up to one order of magnitude more metal than the NaCl-rich brine. Though the exact origin of major cations and metals of the two brines remains uncertain, their contrasting compositions indicate that the two brines had distinct flow paths and fluid-rock interactions. Large-scale circulation of the brines in the Athabasca Basin and Basement was therefore a key parameter for metal mobility (including U) and formation of unconformity-related U deposits.

Solubility of NaCl in water and its melting point by molecular dynamics in the slab geometry and a new BK3-compatible force field.

Abstract: Saturated concentration of rock salt in water is determined by a simulation of brine in contact with a crystal in the slab geometry. The NaCl crystals are rotated to expose facets with higher Miller indices than [001] to brine. The rock salt melting point is obtained by both the standard and adiabatic simulations in the slab geometry with attention paid to finite size effects as well as to a possible influence of facets with higher Miller indices and applied stress. Two force fields are used, the Lennard-Jones-based model by Young and Cheatham with SPC/E water and the Kiss and Baranyai polarizable model with BK3 water. The latter model is refitted to thermomechanical properties of crystal NaCl leading to better values of solubility and the melting point.

EOR by Low Salinity Water and Surfactant at Low Concentration: Impact of Injection and in Situ Brine Composition

Abstract: Low salinity water (LSW) and low salinity surfactant (LSS) core flooding experiments were performed to study the impact of ionic composition on oil recovery from aged Berea sandstone cores. Surfactant adsorption in packed beds, contact angles, interfacial tension (IFT), critical micellar concentration (CMC), and end-point relative permeabilities were used to better understand wettability alteration. In the samples aged with the same in situ brine with (Ca2+ + Mg2+)/Na+ = 0.033, both end-point relative permeabilities of LSW flooding and contact angles showed LSW with only sodium chloride made the samples more water-wet than LSW with divalent-contained brines. Oil recovery was also highest in LSW injection with only sodium chloride. In tertiary LSS of the same core samples, according to both flooding and contact angles, LSS with only sodium chloride showed more water wetness. Characterization measurements showed that, at higher Ca2+/Na+ ratio, CMC and IFT were lower whereas surfactant adsorption was higher....

Anti-icing properties of a superhydrophobic surface in a salt environment: an unexpected increase in freezing delay times for weak brine droplets

Abstract: Superhydrophobic coatings on the aluminum alloy were fabricated by intensive nanosecond pulsed laser treatment and chemical surface hydrophobization, which are chemically stable in contact with 0.5 M NaCl aqueous solutions and mechanically durable against stresses arising in the repetitive freezing/thawing of brine. The statistics of the crystallization of ensembles of sessile supercooled droplets deposited on above superhydrophobic coatings indicate considerable anti-icing properties. The comparative analysis of crystallization statistics of deionized water and of brine at a temperature of −20 °C allows detecting a striking increase in freezing delay times for the latter case with freezing delay for brine droplets reaching more than 6 hours. We explain the observed phenomenon based on the structure of the double electric layer in the vicinity of the hydrophobic surface and the solution/air interface and on the concept of structure making/breaking ions.

Formation and development of salt crusts on soil surfaces

Abstract: The salt concentration gradually increases at the soil free surface when the evaporation rate exceeds the diffusive counter transport. Eventually, salt precipitates and crystals form a porous sodium chloride crust with a porosity of 0.43 ± 0.14. After detaching from soils, the salt crust still experiences water condensation and salt deliquescence at the bottom, brine transport across the crust driven by the humidity gradient, and continued air-side precipitation. This transport mechanism allows salt crust migration away from the soil surface at a rate of 5 μm/h forming salt domes above soil surfaces. The surface characteristics of mineral substrates and the evaporation rate affect the morphology and the crystal size of precipitated salt. In particular, substrate hydrophobicity and low evaporation rate suppress salt spreading.

Experimental Measurement of CO2 Solubility in Aqueous NaCl Solution at Temperature from 323.15 to 423.15 K and Pressure of up to 20 MPa

Abstract: Interest in CO2 solubility in brine at high pressure and high temperature has grown in the last few decades. Solubility data are especially important in petroleum geology, carbon capture and geological storage, and geothermal reservoir engineering. Nevertheless, for the CO2 + NaCl + H2O system there are fewer solubility data available in literature, particularly at high salt molality. A high-pressure experimental device was designed to perform measurements for carbon dioxide solubility in a complex aqueous solution. The apparatus was first validated from experiment on the CO2–pure water system at 323.15 K by comparison with literature data. Thirty-six new experimental solubility data point were obtained in the pressure range between 5 and 20 MPa at three temperatures (323.15, 373.15, and 423.15 K) and at three molalities of NaCl (1, 3, and 6 moles per kilogram of water). Solubility measurements were obtained by potentiometric titration after sample trapping in a sodium hydroxide solution. The experimental...