Brine Chemistry Research Articles

Understanding the Scales Formation Inhibition Mechanism on C-Steel in a Sour media

Corrosion control in sour environments is a serious challenge for oil and gas industry. One of the approaches to mitigate such problem is to use corrosion inhibitors (CI). The selection of a single or a mixture of CIs for a particular oil or gas production, transportation or storage facility depends on different parameters e.g. the ratio between carbon dioxide and hydrogen sulfide, pH, pressure, temperature, and brine chemistry where different kinds of iron sulfide and/or iron carbonate layers can be formed. To select the right corrosion inhibitor/s, it is highly crucial to understand the mechanism of corrosion of C-steel and its inhibition in H2S systems in absence and presence of CIs [1,2]. In this work, the electrochemical behavior of C-steel in (i) deionized water (DIW) and (ii) different NaCl solutions were examined in an H2S system. A series of experiments were conducted at different temperatures and two concentrations of inhibitors (A and B). The corrosion behavior of C-steel was investigated by measuring the open circuit potential (OCP), linear polarization resistance (LPR), and potentiodynamic polarization (PDP) in addition to scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX) besides Raman spectroscopy (RS). The results have shown that the corrosion rate of C-steel gradually decreased then stabilized with time in the inhibited solutions. The inhibition efficiency was found to increase in the presence of both types of inhibitors with temperatures. Surface analysis shows that no film of corrosion products existed. In fact, CIs controlled the corrosion process and prevented passive film formation (iron sulfide), even in the presence of H2S in all tests. 2.5.0.0 2.5.0.0

Permanent CO2 Trapping through Localized and Chemical Gradient-Driven Basalt Carbonation.

Recent laboratory and field studies have demonstrated that basalt formations may present one of the most secure repositories for anthropogenic CO2 emissions through carbon mineralization. In this work, a series of high-temperature, high-pressure core flooding experiments was conducted to investigate how transport limitations, reservoir temperature, and brine chemistry impact carbonation reactions following injection of CO2-rich aqueous fluids into fractured basalts. At 100 °C and 6.3 mM [NaHCO3], representative of typical reservoir conditions, carbonate precipitates were highly localized on reactive mineral grains contributing key divalent cations. Geochemical gradients promoted localized reaction fronts of secondary precipitates that were consistent with 2D reactive transport model predictions. Increasing [NaHCO3] to 640 mM dramatically enhanced carbonation in diffusion-limited zones, but an associated increase in clays filling advection-controlled flow paths could ultimately obstruct flow and limit sequestration capacity under such conditions. Carbonate and clay precipitation were further enhanced at 150 °C, reducing the pre-reaction fracture volume by 48% compared to 35% at 100 °C. Higher temperature also produced more carbonate-driven fracture bridging, which generally increased with diffusion distance into dead-end fractures. In combination, the results are consistent with field tests indicating that mineralization will predominate in buffered diffusion-limited zones adjacent to bulk flow paths and that alkaline reservoirs with strong geothermal gradients will enhance the extent of carbon trapping.

Pinnoite Deposit in DaQaidam Saline Lake, Qaidam Basin, China: Hydroclimatic, Sedimentologic, and Geochemical Constraints

Mg-borates were traditionally thought to be diagenetic products of other primary borate minerals. Here we report results from the study of pinnoite deposit from DaQaidam saline lake, indicating that pinnoite minerals are primary in origin. Within the detecting limit of X-ray powder diffraction analysis (XRD) analysis, no other borate minerals than pinnoite are detected from the Mg-borate deposit. The cemented pinnoite orebody shows the sedimentary structure of light-dark lamination couplets, which signal marked seasonal variations in brine chemistry. The scanning electronic microscopy coupled with an energy dispersive X-ray spectrometer (SEM-EDX) examination reveals that all pinnoite minerals displayed euhedral, giving no indication of diagenetic origin. A marked shift in lithology from clastic sediment to evaporitic deposit reflects a critical change in sedimentation regime associated with abrupt changes in hydroclimatic conditions. The deposition of the pinnoite ore-layer containing abundant hydromagnesite marked the beginning of the evaporite formation and the end of the clastic deposition. This suggests that aridification occurred abruptly and the saline lake was much more alkaline than today in the early-stage of the evaporite deposition. The intensified summer evaporation and seasonal variations in water chemistry brought about a shallow to nearly desiccated paleo-lake with pH exceeding 9.3, Mg/Ca ratio >39, and boron concentration >600 mg/L, which favored pinnoite precipitation and the formation of pinnoite deposit in the central DaQaidam saline lake.

Dynamic interactions of inorganic species at carbonate/brine interfaces: An electrokinetic study

Adjusting brine chemistry during waterflooding of carbonate and clastic reservoirs shows favorable impact on oil recovery. In carbonates, inorganic ions in the injection water play a key role on altering rock-fluid interactions and subsequently influencing rock wettability. Emphasis in this study is given to the direct measurements of carbonate particles zeta potential at different ionic content and aging times. A disturbance at interfaces was observed for most brine solutions especially within the first hour of interactions. The zeta potential of particles became steady with time as a result of attaining chemical equilibrium at interfaces. Individual ions including cations, and anions altered carbonate zeta potential and interacted differently at interfaces, in spite of having an identical salinity. Monovalent ions, for example sodium, significantly reduced the absolute surface potential of limestone particles. The hardness ions, calcium and magnesium, reversed the zeta potential of both calcite and limestone particles towards the positive side. The electrical properties, in general, were found to be affected by the ionic content and cation to anion ratio in the injection water. The dissolved divalent cations play a role in the interactions at the Stern layer boundary, which eventually impact the zeta potential at interfaces. In view of these zeta potential results, specific brines – SmartWater (10-times diluted seawater), key ions (calcium, magnesium and sulfates) and salt solutions containing strictly sodium or sulfate – were able to create electrical repulsions between oil/water and carbonate-particles/water interfaces. As a result, such tailored brines will alter the rock wettability to water-wet and therefore can enhance the oil recovery in carbonate reservoirs. This further understanding of ions specific impact on surface potential, hence wettability, provide essential insights for the successful design of optimal SmartWater recipes.

An Analytical Solution to Interpret Active Ion Transport During Chemically‐Tuned Waterflooding Process in High‐Temperature Carbonate Rocks

AbstractRecent studies on carbonate reservoirs suggest that modifying the injected brine chemistry leads to a competition amongst ions at the rock surface sites, causing alteration in the rock wettability. As such, the potential increase in oil recovery heavily relies on the relationship between the ion transport and chemical reaction. In this work, we highlighted the three processes that govern this relationship as advection by fluid transport, hydrodynamic dispersion resulting in spreading, and sorption of the ions to the rock. An analytical solution to the mathematical equations describing solute reactive transport was derived based on the advection‐reaction‐dispersion equation (ARDE). Our model was first used to replicate produced ion histories from single phase experiments to emphasize the impact of the active ions on rock surface sites. We then studied the movement of the active ions by predicting the breakthrough composition of different ions during oil‐brine displacement experiments and evaluated the impact of the transport and reaction parameters on the wettability change. The wettability change profile was captured in terms of the sorbed ion concentration, where a high retardation was observed for the active ions. The observed oil recoveries in a data set of two‐phase experiments were correlated to the resultant effect of the rock surface chemistry. This study highlights the importance of rock surface chemistry on wettability change and oil production from carbonate rocks.

Variation of the Chemistry of the Dead Sea Brine as Consequence of the Decreasing Water Level

For many years, the Dead Sea suffers from an annual inflow deficiency of about one billion cubic meters, flood and baseflow. The water level changes are related to the majority of surface water inflows diverted for irrigation purposes, in addition to intensive loss of water by the high rate of evaporation and industrial water use. This causes the Dead Sea water level to decline about 35 m within the last 50 years for a long-term average of about 0.79 m per year. The changes in the hydrochemical composition were simulated experimentally to determine the changes that take place as a function of brine water evaporation level and its density. The Total Dissolved Solids (TDS) and the density of the Dead Sea water varies as a function of its water evaporation level changes. It was found that the density variation is not following a linear function with respect to water volume changes. But it follows the total amount of precipitate that occurred at different water levels. The electrical conductivity (EC) changes with respect to time and the prevailing temperature. There was no formula to calculate the high salinity of brine water above the normal ocean water. Consequently, the EC measurements were adopted to represent the Dead Sea water salinity. But in this research a converging factor (0.80971) has been found to convert the TDS values into salinity values. On contrary, the pH values revealed an inverse relationship with respect to the evaporation levels.

Exploring mechanisms for wettability alteration in low-salinity waterfloods in carbonate rocks

Low Salinity waterfloods, even in carbonates, have received a great deal of attention because of their potential to significantly increase waterflood recoveries in addition to being cost effective. Wettability alteration has been found to play a major role in affecting higher recoveries from carbonates in low salinity floods. A large volume of research has accumulated for determining the effect of brine chemistry on wettability alteration and consequent recoveries. Both divalent cations (Ca2+, Mg2+) and anions (SO42−) as well as their interactions have been found to affect wettability. Charges on the mineral surface were also linked to observed wettability change. Despite the efforts, a clear understanding of the mechanisms for such wettability changes seems to be still elusive. Here in our work, first we have attempted to find viable alternatives for sulfates which pose fouling risks for reservoirs. Sulfur oxyanions such as bisulfites and metabisulfites have been found to be potential anions capable of affecting the desired wettability change without the risk associated with sulfates. Secondly, an effort has been made to understand the mechanism (s) behind such wettability alteration in carbonates during low salinity waterfloods based on our work and that by various authors. A potential mechanism has been proposed for wettability alteration, which seems to explain the works of many researchers. The mechanism is based on the isoelectric point of the carbonate rock surface, pH and interfacial energy between the aqueous brine solution and the rock surface. It is proposed that carbonates would be strongly oil-wet at the isoelectric point of the carbonate rock crystal, when the aqueous solution-rock interfacial tension is maximum. On the other hand, it would exhibit more water-wet or less oil-wet behavior, the further the pH of the brine solution is away from the isoelectric point of the carbonate rock. The wettability change is as a result of electrostatic attraction between polar water molecules with the charged surface that helps to bring down the brine-rock interfacial energy. This minimization of interfacial energy is manifested as the wettability change at the 3- phase carbonate mineral-oil-water contact line. The shift in the isoelectric point due to changes imposed in brine composition needs to be accounted for in addition to brine pH and salinity in order to optimize recoveries from low-salinity waterfloods.

Influence of Individual Ions on Oil/Brine/Rock Interfacial Interactions and Oil–Water Flow Behaviors in Porous Media

The low salinity effect (LSE) in enhanced oil recovery (EOR) is widely accepted. However, its underlying mechanisms remain unclear due in part to the complex interactions at the oil/brine/rock interface. The chemistry of brine largely depends on the ionic composition. Thus, in this work, attention was placed on the roles of individual ions and salinity in LSE through direct measurements of oil/brine/rock interfacial behaviors, oil displacement efficiencies, and oil–water relative permeability in sandstone porous media. The results showed that the oil/water interfacial tensions (IFTs) were weakly dependent on ion and the lowest IFTs were generated at the salinities of 0.2–0.5 wt %. In contrast, the interfacial dilational modulus varied significantly with ion types and salinities due to the adsorption of polar components at the oil/water interface. Moreover, wettability alteration of the sandstone surface was found to be associated with the divalent ions in our work. As a result of the viscoelastic interfac...

Deposition of a saline giant in the Mississippian Windsor Group, Nova Scotia, and the nascent Late Paleozoic Ice Age

Saline giants are vast marine evaporite deposits that currently have no modern analogues and remain one of the most enigmatic of chemical sedimentary rocks. The Mississippian Windsor Group (ca. 345Ma), Maritimes Basin, Atlantic Canada is a saline giant that consists of two evaporite-rich sedimentary sequences that are subdivided into five subzones. Sequence 1 is composed almost entirely of thick halite belonging to Subzone A (Osagean). Sequence 2 is in unconformable contact and comprised of stacked carbonate-evaporite peritidal cycles of Subzones B through E (Meramecian). Subzone B, the focus of research herein, documents the transition from wholly evaporitic to open marine conditions and thus, preserves an exceptional window into the processes forming saline giants.Lithofacies stacking patterns in Subzone B reveal that higher-order fluctuations in relative sea level produced nine stacked parasequences interpreted to reflect high frequency glacioeustatic oscillations during the onset of the Late Paleozoic Ice Age. Each parasequence reflects progradation of intertidal and sabkha sediments over subtidal carbonate and evaporite deposits. Dissimilarities in cycle composition between sub-basins imply the development of contrasting brine chemistries from differing recharge rates with the open ocean.What the Windsor Group shows is that evaporite type is ostensibly linked to the amplitude and frequency of sea level rise and fall during deposition. True saline giants, like the basinwide evaporites of Sequence 1, apparently require low amplitude, long frequency changes in sea level to promote the development of stable brine pools that are only periodically recharged with seawater. By contrast, the high amplitude, short frequency glacioeustatic variability in sea level that controlled the accumulation of peritidal evaporites in Subzone B produce smaller, subeconomic deposits with more complex facies relationships.

Permeability and Mineral Composition Evolution of Primary Seal and Reservoir Rocks in Geologic Carbon Storage Conditions

It has been reported that deep saline aquifers represent the largest geologic CO2 storage resource. To better predict containment effectiveness and long-term reservoir behavior of these formations, it is important to understand the potential geochemically induced changes to the porosity and permeability of both the primary sealing formation and CO2 storage formation rocks. To investigate these potential changes, an experimental study to probe the geochemical interactions of CO2/brine/rock system under geologic CO2 storage conditions was conducted in a static reaction system. Marine shale (primary sealing formation) and Lower Tuscaloosa sandstone (CO2 storage formation) core samples taken from the Plant Daniel CO2 storage test site (Jackson County, Mississippi) were exposed to CO2-saturated brine in a batch reactor at relevant geologic storage conditions (85°C and 23.8 MPa CO2 pressure) for 6 months. X-ray diffraction, scanning electron microscopy, computed tomography, and brine chemistry analyses were performed before and after the exposure. Permeability measurements from the marine shale and sandstone core samples before and after CO2/brine exposure indicated a significant effective permeability change. Sealing marine shale permeability increased following exposure while the permeability of the sandstone from the storage formation was observed to decrease. Analysis results of the primary sealing formation sample (marine shale) at the Plant Daniel CO2 storage test site have not been reported before. The permeability decrease of the Lower Tuscaloosa sandstone sample reported in this study verifies the results reported in a previous study. These results have implications for the integrity of the primary seal in a CO2 storage setting.

Development of a novel once-through flow visualization technique for kinetic study of bulk and surface scaling.

There is a considerable interest to investigate surface crystallization in order to have a full mechanistic understanding of how layers of sparingly soluble salts (scale) build on component surfaces. Despite much recent attention, a suitable methodology to improve on the understanding of the precipitation/deposition systems to enable the construction of an accurate surface deposition kinetic model is still needed. In this work, an experimental flow rig and associated methodology to study mineral scale deposition is developed. The once-through flow rig allows us to follow mineral scale precipitation and surface deposition in situ and in real time. The rig enables us to assess the effects of various parameters such as brine chemistry and scaling indices, temperature, flow rates, and scale inhibitor concentrations on scaling kinetics. Calcium carbonate (CaCO3) scaling at different values of the saturation ratio (SR) is evaluated using image analysis procedures that enable the assessment of surface coverage, nucleation, and growth of the particles with time. The result for turbidity values measured in the flow cell is zero for all the SR considered. The residence time from the mixing point to the sample is shorter than the induction time for bulk precipitation; therefore, there are no crystals in the bulk solution as the flow passes through the sample. The study shows that surface scaling is not always a result of pre-precipitated crystals in the bulk solution. The technique enables both precipitation and surface deposition of scale to be decoupled and for the surface deposition process to be studied in real time and assessed under constant condition.

Can we use pyroxene weathering textures to interpret aqueous alteration conditions? Yes and No

Pyroxene minerals are a significant component of Shergottite-Nakhlite-Chassignite (SNC) meteorites (e.g., Velbel 2012) and detected across large areas of Mars’ surface (e.g., Mustard et al. 2005). These minerals are associated with chloride, sulfate, and perchlorate salts that may represent briny waters present in Mars’ history. Previous textural analyses by Velbel and Losiak (2010) comparing pyroxenes and amphiboles from various natural weathering environments showed no correlation between apparent apical angles (describing the morphology of denticular weathering textures) and mineralogy or aqueous alteration history in relatively dilute solutions. However, high-salinity brines preferentially dissolve surface species, potentially leading to different textures dependent on the brine chemistry. In this study, we performed controlled pyroxene dissolution experiments in the laboratory on a well-characterized diopside to determine if aqueous alteration in different high-salinity brines, representative of potential weathering fluids on Mars, produce unique textural signatures. Following two months of dissolution in batch reactors, we observed denticles on etch pit margins and pyroxene chip boundaries in all of the solutions investigated: ultrapure water (18 MΩ cm −1 ; a H 2 O = 1); low-salinity solutions containing 0.35 M NaCl ( a H 2 O = 0.99), 0.35 M Na 2 SO 4 ( a H 2 O = 0.98), and 2 M NaClO 4 ( a H 2 O = 0.9); and near-saturated brines containing 1.7 M Na 2 SO 4 ( a H 2 O = 0.95), 3 M NaCl ( a H 2 O = 0.75), and 4.5 M CaCl 2 ( a H 2 O = 0.35). No systematic change in denticle length or apical angle was observed between any of the solutions investigated, even when altered in brines with significantly different salinity, activity of water, and anion composition. Based on these and previous results from natural systems, apical angle measurements are not a useful proxy for determining the extent or nature of aqueous alteration. However, since denticles form relatively slowly during weathering at circum-neutral pH, denticle length may be a useful proxy for chemical weathering duration. All of the experimental solutions produced median denticle lengths ≤1 μm, likely due to the brief weathering experiments. However, perchlorate brines produced a significantly wider range of denticle lengths than those observed in all the other experimental solutions tested. Since perchlorate is likely a common constituent in martian soils (Glotch et al. 2016), denticle length measurements should be used cautiously as proxies for extent of aqueous alteration on Mars, particularly in samples that also contain perchlorate.

Microemulsion-enhanced displacement of oil in porous media containing carbonate cements

Subsurface porous formations containing nonaqueous phase liquids (NAPLs) such as crude oils are often targets for surfactant flooding during enhanced oil recovery (EOR) or aquifer remediation processes designed to mobilize and solubilize oil. Recent studies suggested that putting surfactants into micro-emulsified state prior to injection might improve their performance. Most of these studies proved that microemulsion (ME) efficiency depends on test conditions and the proper selection of their chemical formulations and brine chemistry. However, the impact of rock characteristics on the complex fluid-rock interactions is still unclear, especially in heterogeneous rocks. The goal of this fundamental study was to examine the effect of MEs on oil displacement in three different aged rocks (Berea, Edwards, and Tensleep) and identify the test conditions in which MEs outperform surfactants. The effectiveness of surfactants and MEs was evaluated at two concentrations from different sets of spontaneous imbibition tests and petrographic analyses. Several mechanisms such as reduction of interfacial tension (IFT), oil emulsification, and wettability alteration were responsible for the improved recovery. Wettability alteration of aged cores by surfactants and MEs led to an early oil removal by spontaneous imbibition while emulsification increased the ultimate amount produced. Both additives lowered the IFT from 12 to less than 1 mN/m. However, high ME concentration was able to decrease the size of oil droplets by one order of magnitude, significantly enhancing oil mobilization in all three rocks. The solubilization capability of MEs was superior in Tensleep due to their unique ability to penetrate dolomite cements and alter their wettability.

CO2 Plume Migration and Fate at Sleipner, Norway: Calibration of Numerical Models, Uncertainty Analysis, and Reactive Transport Modelling of CO2 Trapping to 10,000 Years

The Sleipner Project in Norway is the world's first industrial-scale geological carbon dioxide storage project. Time-lapse seismic monitoring data have been collected, tracing CO2 plume development from 1996 to 2010. Therefore, the Sleipner Project provides a somewhat unique opportunity to simulate the dynamics of CO2 in a real geological system. The purpose of this study is to simulate CO2 plume migration dynamics and assess the impact of uncertain factors on short and long term migration and fate of CO2 for the uppermost layer (Layer 9) of the Utsira Sand.First, we applied a multi-phase compositional simulator to the Sleipner Benchmark model for Layer 9 and calibrated our model against the time-lapsed seismic monitoring data at the site from 1999 to 2008. By adjusting lateral permeability anisotropy, CH4 in the CO2 stream, and reservoir temperature, approximate match with the observed plume was achieved. Model-predicted gas saturation, thickness of the CO2 accumulation, and CO2 solubility in brine (none of them used as calibration metrics) were all comparable with interpretations of the seismic data in the literature.Second, hundreds of simulations of parameter sensitivity (pressure, temperature, feeders, spill rates, relative permeability curves, and CH4 content) were conducted for the plume migration, based on the calibrated model. The results showed that simulated plume extents are sensitive to permeability anisotropy, temperature, and CH4 content, but not sensitive to the other parameters. However, adjusting a single parameter within the reported range of values in the literature would not reproduce the north-south trending CO2 plume; it took a combination of permeability, CH4, and temperature adjustments to match simulated CO2 plume with seismic monitoring data. Although there is a range of uncertain parameters, the predicted fate of CO2 fell within a narrow band, ∼ 93±2% structural trapping and ∼ 7±2% solubility trapping. The calibrated model is not unique. Many combinations of permeability anisotropy, temperature, and CH4 would produce similar matches. Other possibilities that would have improved the development of an N–S elongated CO2 plume, such as a slight tilting of the surface of Utsira top to the south, were not experimented in this study, but are worthy of exploration for future studies.Finally, we used coupled reactive mass transport model to investigate the effects of rate laws and regional groundwater flow on long-term CO2 fate in Layer 9. The mineral composition and brine chemistry for the Utsira sand were adopted from the literature, and we modelled 100 year injection and continued water-rock interaction to 10,000 years. The results indicated that: (1) The predicted fraction of CO2 mineral trapping when using the linear rate law for feldspar dissolution is twice as much as when using the non-linear rate law. (2) Mineral trapping is more significant when regional groundwater flow is taken into consideration. Under the influence of regional groundwater flow, the replenishment of fresh brine from upstream continuously dissolves CO2 at the tail of CO2 plume, generating a larger acidified area where mineral trapping takes place. In a Sleipner like aquifer, the upstream replenishment of groundwater results in ∼ 22% mineral trapping at year 10,000, compared to the ∼ 4% when the effects of regional groundwater are ignored.

Iron cycling in the anoxic cryo-ecosystem of Antarctic Lake Vida

Iron redox cycling in metal-rich, hypersaline, anoxic brines plays a central role in the biogeochemical evolution of life on Earth, and similar brines with the potential to harbor life are thought to exist elsewhere in the solar system. To investigate iron biogeochemical cycling in a terrestrial analog we determined the iron redox chemistry and isotopic signatures in the cryoencapsulated liquid brines found in frozen Lake Vida, East Antarctica. We used both in situ voltammetry and the spectrophotometric ferrozine method to determine iron speciation in Lake Vida brine (LVBr). Our results show that iron speciation in the anoxic LVBr was, unexpectedly, not free Fe(II). Iron isotope analysis revealed highly depleted values of −2.5‰ for the ferric iron of LVBr that are similar to iron isotopic signatures of Fe(II) produced by dissimilatory iron reduction. The presence of Fe(III) in LVBr therefore indicates dynamic iron redox cycling beyond iron reduction. Furthermore, extremely low δ18O–SO42− values (−9.7‰) support microbial iron-sulfur cycling reactions. In combination with evidence for chemodenitrification resulting in iron oxidation, we conclude that coupled abiotic and biotic redox reactions are driving the iron cycle in Lake Vida brine. Our findings challenge the current state of knowledge of anoxic brine chemistry and may serve as an analogue for icy brines found in the outer reaches of the solar system.

Nanoscale Morphology of Brine/Oil/Mineral Contacts in Connected Pores of Carbonate Reservoirs: Insights on Wettability From Cryo-BIB-SEM

Summary We used broad-ion-beam slope cutting in combination with scanning electron microscopy undertaken under cryogenic conditions (Cryo-BIB-SEM) to study mineral/oil/brine contacts in reservoir carbonates. This direct-imaging method allows pore-scale investigation of in-situ fluids and their distributions down to the nanometer scale. In this study, we compare two types of carbonate reservoirs: a fine-grained Lixhe limestone (Belgium) and a coarse-grained limestone from the Maastricht area (The Netherlands). In both rock types, we first quantify the porosity with BIB-SEM and derive the spatially resolved pore connectivity of the rock from BIB-SEM on Wood's Metal (WM) injected subsamples. In the second step, subsamples were saturated with the oil analog n-hexadecane, and then flooded with NaCl brine and MgSO4 brine, respectively, to study the effect of the brine chemistry on the microscopic fluid distribution. Cryo-BIB-SEM in combination with high-resolution energy-dispersive-spectroscopy (EDS) imaging and automated image analysis on the saturated samples allowed for a quantification of the oil-droplet size, the lengths of carbonate/oil interfaces, and the 2D contact angle of carbonate with brine and oil. Our results show that these features (e.g., interface length, contact angles, effect of asperities) are present on the scale of a few tens of nanometers to a few micrometers, which is in agreement with numerous theoretical and experimental studies. Lixhe limestone showed relatively less carbonate/oil contacts despite a larger oil fraction in the MgSO4-brine-flooded sample compared with the sample flooded with NaCl brine, indicating a more-hydrophilic nature of the carbonate surface in this experiment. This feasibility study showed that the technique permits the testing of predictions on the morphology and dynamics of contact lines in relation to the mineral properties, which is not possible with other imaging methods, such as X-ray microcomputed tomography (µ-CT), because of limits in resolution.

CO2/brine/rock interactions in Lower Tuscaloosa formation

AbstractSaline aquifers are the largest potential continental geologic CO2 sequestration resource. Understanding of potential geochemically induced changes to the porosity and permeability of host CO2 storage and sealing formation rock will improve our ability to predict CO2 plume dynamics, storage capacity, and long‐term reservoir behavior. Experiments exploring geochemical interactions of CO2/brine/rock on saline formations under CO2 sequestration conditions were conducted in a static system. Chemical interactions in core samples from the Lower Tuscaloosa formation from Jackson County, Mississippi, with exposure to CO2‐saturated brine under sequestration conditions were studied through six months of batch exposure. The experimental conditions to which the core samples of Lower Tuscaloosa sandstone and Selma chalk were exposed to a temperature of 85°C, CO2 pressure of 23.8 MPa (3500 psig), while immersed in a model brine representative of Tuscaloosa Basin. Computed tomography (CT), X‐Ray diffraction (XRD), Scanning Electron Microscopy (SEM), brine chemistry, and petrography analyses were performed before and after the exposure. Permeability measurements from the sandstone core sample before and after exposure showed a permeability reduction. No significant change of the permeability measurements was noticed for the core sample obtained from Selma chalk after it was exposed to CO2/brine for six months. These results have implications for performance of the storage interval, and the integrity of the seal in a CO2 storage setting. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Removal of Radium from Synthetic Shale Gas Brines by Ion Exchange Resin

Abstract Rapid development of hydraulic fracturing for natural gas production from shale reservoirs presents a significant challenge related to the management of the high-salinity wastewaters that return to the surface. In addition to high total dissolved solids (TDS), shale gas-produced brines typically contain elevated concentrations of radium (Ra), which must be treated properly to prevent contamination of surface waters and allow for safe disposal or reuse of produced water. Treatment strategies that isolate radium in the lowest volume waste streams would be desirable to reduce disposal cost and generate useful treatment by-products. The present study evaluates the potential of a commercial strong acid cation exchange resin for removing Ra2+ from high-TDS brines using fixed-bed column reactors. Column reactors were operated with varying brine chemistries and salinities in an effort to find optimal conditions for Ra2+ removal through ion exchange. To overcome competing divalent cations present in the b...

Can sodium NMR provide more than a tracer for brine in petrophysics?

Sodium has been suggested as a tracer for brine in reservoir formations, where sodium ions are found exclusively in the aqueous phase, and can be detected by time-domain nuclear magnetic resonance (NMR). To date, petrophysical applications of sodium-23 NMR have focused on concentrated NaCl electrolyte solutions where the nuclear spin relaxation time is related to ion concentration. Therefore, a measure of brine volume is achieved directly from the sodium signal amplitude and relaxation time, available in a single measurement. However, real reservoir formation or injection brines contain many different ionic moieties. Sodium-23 relaxation times and diffusion coefficients are measured using time-domain NMR and pulsed field gradient (PFG) NMR techniques, respectively, and shown to depend strongly on the ions present in solution. Correlations between sodium-23 relaxation times and sodium ion concentration are found to differ depending on the cations and other anions present in the brine. However, consistent correlations are obtained for sodium-23 relaxation times and diffusion coefficient, and brine viscosity, regardless of the ionic content of the brine. In general, sodium-23 NMR remains a qualitative technique for monitoring changes in sodium concentration or brine volume (at constant salinity) in reservoir formations. However, if knowledge of the brine chemistry is available, then sodium-23 NMR offers a non-invasive and quantitative method of robustly measuring brine volume and viscosity in petrophysical applications.

Influence of magmatic-hydrothermal activity on brine evolution in closed basins: Searles Lake, California

Research Article| September 01, 2016 Influence of magmatic-hydrothermal activity on brine evolution in closed basins: Searles Lake, California Tim K. Lowenstein; Tim K. Lowenstein † 1Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA †lowenst@binghamton.edu Search for other works by this author on: GSW Google Scholar Lauren A.C. Dolginko; Lauren A.C. Dolginko 1Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA Search for other works by this author on: GSW Google Scholar Javier García-Veigas Javier García-Veigas 2CCiTUB, Scientific and Technological Centers, Universitat de Barcelona, 08028 Barcelona, Spain Search for other works by this author on: GSW Google Scholar Author and Article Information Tim K. Lowenstein † 1Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA Lauren A.C. Dolginko 1Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA Javier García-Veigas 2CCiTUB, Scientific and Technological Centers, Universitat de Barcelona, 08028 Barcelona, Spain †lowenst@binghamton.edu Publisher: Geological Society of America Received: 04 Aug 2015 Revision Received: 07 Feb 2016 Accepted: 05 Apr 2016 First Online: 02 Jun 2017 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2016 Geological Society of America GSA Bulletin (2016) 128 (9-10): 1555–1568. https://doi.org/10.1130/B31398.1 Article history Received: 04 Aug 2015 Revision Received: 07 Feb 2016 Accepted: 05 Apr 2016 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Tim K. Lowenstein, Lauren A.C. Dolginko, Javier García-Veigas; Influence of magmatic-hydrothermal activity on brine evolution in closed basins: Searles Lake, California. GSA Bulletin 2016;; 128 (9-10): 1555–1568. doi: https://doi.org/10.1130/B31398.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Evaporites in a 700-m-long core (KM-3) from Searles Lake, California, preserve a record of the chemical evolution of inflow waters. Chemical analyses of fluid inclusions in halite and evaporite minerals show that the major ion composition of inflow waters to Searles Lake was changed by distant hydrothermal activity associated with magmatism at Long Valley caldera between 1.27 and 1.0 m.y. ago. Below core depths of 291 m, the evaporites consist of Ca-bearing sulfates (anhydrite, glauberite) and halite; fluid inclusions in the halite show that parent waters were Na+-Cl–-SO42–-rich waters. Above 291 m, the evaporites include sodium carbonates (pirssonite, trona) and halite, and fluid inclusion brines are Na+-K+-HCO3–-CO32–-Cl–-SO42–-rich. These fluctuations in mineralogy and brine chemistry document an alkalinity spike beginning between 1.27 and 1.0 Ma, when inflow waters to Searles Lake crossed the CaCO3 chemical divide and began to produce alkaline brines that precipitated trona upon evaporation.The Owens River is a modern chemical analog for inflow water into Searles Lake beginning between 1.27 Ma and 1.0 Ma. A major contributor of solutes to the Owens River is Hot Creek in Long Valley caldera, which is fed by hydrothermal springs with high alkalinity from magmatically derived CO2. The timing of magmatism in Owens Valley and the appearance of sodium carbonate minerals in core km-3 suggest a causal relationship. Volcanism and hydrothermal activity provided CO2 and elevated alkalinity to Searles Lake inflow waters 0.5–0.2 m.y. before the eruptions that formed the Bishop Tuff and Long Valley caldera. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.