Increase In Viscosity Of Water Research Articles

Effects of temperature-dependent viscosity on thermal drawdown-induced fracture flow channeling in enhanced geothermal systems

Harnessing geothermal energy from an enhanced geothermal system (EGS) highly depends on fracture flow and heat transport processes. Thermal drawdown-induced thermal stress has been characterized as a major reason for severe fracture flow channeling (short-circuiting), which further leads to premature thermal breakthrough and impairs long-term thermal performance. In the present study, we quantitatively analyzed a potential flow channeling mitigation mechanism, i.e., the increase of water viscosity with temperature reduction. Through a field-scale single-fracture EGS model that incorporates thermal-hydro-mechanical coupled processes and temperature-dependent water viscosity, we demonstrate that the increase of water viscosity during heat extraction promotes a dispersed fracture flow pattern, which can effectively mitigate thermal drawdown-induced flow channeling and improve long-term thermal performance. The mitigation effect is more noticeable for homogeneous aperture scenarios than for heterogeneous aperture scenarios, especially in the early period of heat production. With a higher in-situ stress and smaller rock Young's modulus, the flow channeling effect of thermal stress becomes weak, and therefore the temperature-dependent viscosity exhibits a more significant flow channeling mitigation effect. The results from the current study provide valuable insights into the optimization of fracture flow and heat transport to achieve more efficient and sustainable energy production from EGSs.

Microscale Effects of Polymer on Wettability Alteration in Carbonates

Summary Polymer enhances the volumetric sweep efficiency through the increased viscosity of injection water and subsequently results in enhanced oil recovery. Most of the reported experimental studies focused on only evaluating polymer viscosifying characteristics and their associated significance for achieving adequate mobility control in porous media. The microscale effects of polymer on wettability alteration in carbonates are rarely studied. In this experimental investigation, the wettability of carbonates in the presence of polymer was measured using contact angle tests. In addition, the adhesion force between carbonate and crude oil droplets in polymer solutions was determined using a custom-designed integrated thin-film drainage apparatus equipped with a bimorph sensor. The liberation kinetics of crude oil from carbonate surfaces were also measured by an optical microscope-based liberation cell to understand the wettability alteration effects on oil recovery. All the experiments, except the adhesion force, which was measured at room temperature due to the restriction of bimorph sensor, were conducted at both ambient and elevated temperatures (70°C) using a sulfonated polyacrylamide polymer (SPAM) (at 500 and 700 ppm) in high-salinity injection water. Deionized (DI) water was used as a baseline to provide a representative comparison with the high-salinity brine. The contact angles of crude oil droplets on a carbonate surface were highest in DI water and decreased in brine. The addition of polymer decreased the contact angle further, with higher concentrations of polymer resulting in a lower contact angle. The adhesion force between crude oil and carbonate showed good agreement with contact angle data, and the oil adhesion was smallest on the carbonate surface in the presence of polymer. The crude oil liberation from the carbonate surface by flooding with brine and polymer was found to be more efficient at elevated temperature than at ambient temperature, consistent with lower contact angles measured in these aqueous solutions at high temperature. The equilibrium oil liberation degree with polymer solutions increased by more than two times when the temperature was increased from 23 to 70°C. The higher liberation degree obtained with polymer solutions also correlated well with the lowest adhesion force measured between crude oil and carbonate in the presence of polymer. These consistent results obtained from different experimental techniques indicated that the oil recovery improvements observed with polymer in dynamic liberation tests are not only related to the increase in water viscosity but are also due to favorable changes in wettability as inferred from both contact angle and adhesion force measurements. This experimental study, for the first time, characterized the microscale effects of polymer on wettability alteration and crude oil liberation in carbonates. The favorable effect of polymer on wettability alteration in carbonates revealed from this study has not been reported in the literature, and it can become a novel addition to the existing knowledge.

The Key Parameter Effect Analysis Of Polymer Flooding On Oil Recovery Using Reservoir Simulation

As time goes by, there will be decreasing of production rates of a field along with decreasing pressure. This led to the necessity for further efforts to increase oil production. Therefore, pressure support is required to improve the recovery factor. Supportable pressure that can be used can be either water flooding and polymer flooding. This study aims to compare recovery factor to scenarios carried out, such as polymer flooding with different concentrations modeled in the same reservoir model to see the most favorable scenario. The method used in this research is reservoir simulation method with Computer Modeling Group (CMG) STARS simulator. The study was carried out by observing at the pressure, injection rate, and polymer concentration on increasing field recovery factor. This study used cartesian grid with the assumption of homogeneous reservoir, there are no faults or other geological condition in the reservoir, and driving mechanism is only solution gas drive. This reservoir, oil type is light oil with API gravity 40.3˚API and layer of conglomerate rock. The simulation result performed with various scenarios provides a good result. Where the conditions case base case field recovery factor of 6.7%, and after water flooding produced 25.5% of oil, whereas with tertiary recovery method is polymer flooding was carried out with four concentrations of 640 ppm, 1,500 ppm, 3,000 ppm, and 4,000 ppm obtained optimum values at 4,000 ppm polymer concentration with recovery factor 28.9%, SOR reduction final value 0,5255, polymer adsorption of 818,700 ppm, reservoir final pressure 1,707 psi, and an increase in water viscosity to 0.94 cP.

Interactions between Surfactants and Cellulose Nanofibrils for Enhanced Oil Recovery

Chemical enhanced oil recovery (EOR) represents a series of potential solutions for extracting more oil from resources with already known locations and magnitudes. Unfortunately, many of the chemical additives in use today are not environmentally friendly. In the study a “greener” alternative for increasing viscosity of the injection water is investigated, namely cellulose nanofibrils (CNF). The nanofibrils are combined in systems with anionic sulfonate surfactants, SDBS and AOT, in order to decrease interfacial tension (IFT) between oil and water. In combination, the increase of water viscosity and decrease of IFT should result in higher ultimate oil recovery than if only conventional water flooding was applied. Interactions between cellulose nanofibrils and the surfactants have been investigated through adsorption studies, rheology, and IFT measurements. An observed synergy effect between CNF and surfactants upon viscosity of injection water, as well as with substantial decrease in IFT, leads the author...

Impact of Hydrostatic Pressure on an Intrinsically Disordered Protein: A High‐Pressure NMR Study of α‐Synuclein

The impact of pressure on the backbone (15) N, (1) H and (13) C chemical shifts in N-terminally acetylated α-synuclein has been evaluated over a pressure range 1-2500 bar. Even while the chemical shifts fall very close to random coil values, as expected for an intrinsically disordered protein, substantial deviations in the pressure dependence of the chemical shifts are seen relative to those in short model peptides. In particular, the nonlinear pressure response of the (1) H(N) chemical shifts, which commonly is associated with the presence of low-lying "excited states", is much larger in α-synuclein than in model peptides. The linear pressure response of (1) H(N) chemical shift, commonly linked to H-bond length change, correlates well with those in short model peptides, and is found to be anticorrelated with its temperature dependence. The pressure dependence of (13) C chemical shifts shows remarkably large variations, even when accounting for residue type, and do not point to a clear shift in population between different regions of the Ramachandran map. However, a nearly universal decrease in (3) JHN-Hα by 0.22 ± 0.05 Hz suggests a slight increase in population of the polyproline II region at 2500 bar. The first six residues of N-terminally acetylated synuclein show a transient of approximately 15% population of α-helix, which slightly diminishes at 2500 bar. The backbone dynamics of the protein is not visibly affected beyond the effect of slight increase in water viscosity at 2500 bar.

A Study on the Key Influential Factors of a Gas Reservoir's Potential for Aqueous Phase Trapping

Aqueous phase trapping in many oil and gas reservoirs is a noteworthy mechanism of formation damage during drilling, completion, work over, and stimulation operation. Aqueous phase trapping can limit the productivity of a well to a high extent, especially in low permeable gas reservoirs. In this article, using aqueous phase trapping laboratory tests on low permeable sandstone cores' effect of key factors on gas reservoir's potential for aqueous phase trapping was investigated. Studied factors were initial water saturation, permeability, water filtrate viscosity, and drawdown pressure. Results showed that severity of formation damage caused by aqueous phase trapping increases as each of the initial water saturation, permeability, and drawdown pressure decreases. Also, an increase in water viscosity increases APT related damage potential.

Increase of water viscosity under the influence of magnetic field

Effect of applied magnetic field on the water viscosity between 298 and 323K has been investigated. A higher absolute viscosity has been observed in the presence of applied magnetic field compared to no field which has been explained on the basis of stronger hydrogen bonds. The measurement is found to increase consistently at higher temperatures. The relative increase in viscosity Δη∕η0 is of the order of 10−3 in a 7.5kG transverse magnetic field where Δη is the viscosity change compared to the no-field viscosity η0 at a given temperature.

水溶性ポリマー生産微生物を用いたＭＥＯＲにおける油層内挙動と石油増進回収機構に関するシミュレーション研究

Our research group has carried out experimental studies to analyze the performance and the mechanism of MEOR with TU-15A, a microbe that produces water-soluble polymer. In the previous study, a mathematical model for this MEOR was developed, including almost all important phenomena such as growth and death of microbe, consumption of nutrient, production of water-soluble polymer, increase of water viscosity and the flow of reservoir fluids.In this study, the validity of the MEOR simulation model was firstly examined by comparison between experimental and computed results. The results of the numerical simulation agreed with the experimental results in terms of oil recovery, injection pressure, oil cut and flow profile of injection water.Next, numerical simulation was carried out to analyze the performance and mechanism of this MEOR process for five-spot pattern flooding. The procedure and the conditions used are as follows.Step 1: Conduct water flooding until water cut becomes 90%.Step 2: Inject microbe and nutrient solution into reservoir up to 0.1 PV.Step 3: Shut-in and wait for cultivation in the reservoir for 10 days.Step 4: Conduct postflash until water cut becomes 95%.The quantitative changes of microbe, nutrient, water viscosity and oil saturation were analyzed. Regarding the alteration of flow pattern in the reservoir, it was found that (1) the water-soluble polymer produced by the microbe flowed into the main flow channel along the shortest way between the injection well and the production well and water viscosity there increased, (2) subsequently more uniform flow profile of injected water for oil recovery was established, and (3) then the residual oil was mobilized to the production well. The more than 10% additional oil recovery was obtained in the early phase of postflash in this MEOR process compared with waterflooding.

水溶性ポリマー生産微生物を用いたＭＥＯＲのための数値モデルの構築

In Microbial Enhanced Oil Recovery(MEOR) processes, microbe(s) and nutrients are injected into a reservoir, and the microbe increases and produces metabolites such as polymers, surfactants, gases, and/or acids in the reservoir. These metabolites help to mobilize the residual oil. Our research group possesses a microbe Clostridium sp. TU-15A which can produce a water-soluble polymer in the molasses medium and increase the viscosity of the culture solution up to 70mPa•s(at38.3s-1) or higher by a 10 day cultivation. And it was shown by flooding experiments that this microbe was very effective for enhancing the oil recovery5). There seems to be no comprehensive model for MEOR with a microbe producing a water-soluble polymer. In the present study, the experimental data were formulated for developing a numerical model to analyze the performance and the mechanism of MEOR with a microbe producing the water-soluble polymer. In this paper, the concept of this model is discussed and the mathematical model described. The model consists of two phases(oil and water) and five components(oil, water, microbe, nutrient, and metabolite). The model includes almost all cesses of MEOR such as growth and death of microbe, consumption of nutrient, production of water-soluble polymer, increase of water viscosity, change of the flow profile in a reservoir, and enhancement of oil recovery.

Hydraulic conductance in aspen (Populus tremuloides) seedlings exposed to low root temperatures.

Low root temperatures significantly reduced root hydraulic conductivity and increased resistance to water flow through the roots of aspen (Populus tremuloides Michx.) seedlings. Increased resistance to water flow could not be fully explained by the corresponding increase in water viscosity at low temperatures. The shapes of Arrhenius plots of root water flow and the activation energies were dependent on the direction, sequence and extent of temperature change. The Arrhenius plots suggested that the effect of low root temperature on root water flow was mediated by an effect on root metabolism. The low root temperatures tested did not induce root electrolyte leakage normally associated with cell membrane injury. Although a decrease in root temperatures to 7 or 4 degrees C induced a reduction in stomatal conductance, this reduction lagged the decline in root water flow by several hours. In contrast, when soil temperatures were raised from 4 or 7 degrees C to 25 degrees C, root water flow presumably increased, and stomatal conductance responded rapidly and was temporarily higher than before the cold treatment was imposed.

Physiological versus viscosity-induced effects of water temperature on the swimming and sinking velocity of larvae of the serpulid polychaete Galeolaria caespitosa

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 159:209-218 (1997) - doi:10.3354/meps159209 Physiological versus viscosity-induced effects of water temperature on the swimming and sinking velocity of larvae of the serpulid polychaete Galeolaria caespitosa Toby F. Bolton*, Jon. N. Havenhand School of Biological Sciences, The Flinders University of South Australia, GPO Box 2100, Adelaide, South Australia 5001, Australia *E-mail: bitfb@flinders.edu.au Water viscosity is inversely related to water temperature. Because marine invertebrate larvae generally operate in a hydrodynamic environment dominated by viscous forces (i.e. Reynolds numbers <1), temperature-induced changes in water viscosity may exert profound influence on the swimming and sinking velocity of larvae. Whilst the physiological effects of water temperature on larval locomotion have received considerable experimental investigation, the influence of temperature-induced changes in water viscosity has received little attention. We investigated the relative physiological and viscosity-induced effects of water temperature at 25 and 15°C on the swimming and sinking velocity of larvae of the serpulid polychaete Galeolaria caespitosa (L.). Larvae of this species undergo considerable growth and development during their planktonic period such that the Reynolds number of the larval body (trochosphere) increases from 0.19 at hatching to 1.11 at 120 h post-hatching. Consequently we suggest that inertial forces may exert an influence on swimming at the later stages of larval development and therefore the influence of viscosity may change over the course of larval development. We also suggest that a temperature-induced increase in water viscosity will reduce the sinking velocity of larvae and may reduce the energy expenditure required to maintain location in the water column. Our results indicate that both physiological and viscosity components of water temperature influence the swimming velocity of G. caespitosa larvae. However, the influence of water viscosity did not change significantly over the course of larval development. The sinking velocity of G. caespitosa larvae was reduced with a temperature-induced increase in water viscosity. The reduction in sinking velocity of the larvae was proportional to the increase in water viscosity. We estimated and compared the metabolic costs of swimming to counteract sinking at 25 and 15°C by estimating Q10 values from the metabolic effects of temperature on swimming velocity. We suggest that the metabolic costs of swimming to counteract sinking in G. caespitosa larvae are similar at 25 and 15°C, but that the metabolic costs of swimming are slightly higher at 15°C. Larvae · Trochophore · Physiological · Viscosity · Swimming · Sinking · Velocity Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 159. Publication date: November 29, 1997 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1997 Inter-Research.

The state of water associated with the phosphoenzyme of the Ca-ATPase of sarcoplasmic reticulum: A spin probe study

Electron spin resonance spectra of nitroxide free radicals in the aqueous phase associated with suspensions of sarcoplasmic reticulum vesicles have been measured. While the Ca-ATPase was cycling there was a loss of signal which returned to normal as ATP was consumed. The fractional loss of signal increased with protein concentration, but was independent of concentration of spin probe, suggesting that it was unlikely to be due to binding of the probe to one of the conformations assumed by the enzyme during a catalytic cycle. The results are consistent with an increase in viscosity of water associated with the phosphoenzyme intermediate of the ATPase, similar to the increase of viscosity of water which has been observed in hydrophobic pores of synthetic polymers. It is suggested that probes in this relatively viscous microaqueous phase tumble more slowly than probes in the rest of the water, so that with formation of the phosphoenzyme a fraction of the signal broadens and loses peak height.

Effect of temperature on hydraulic conductivity of single capillaries.

Paired determinations of the hydraulic conductivity (Lv) of individually perfused capillaries in frog mesentery were measured at 22-25 and 5-8 degrees C. The mean value of the ratio of the hydraulic conductivity at 22-25 to that at 5-8 degrees C was 1.76 +/- 0.22 (SE) in 10 capillaries perfused with albumin in the Ringer perfusate and 1.81 +/- 0.11 in six capillaries perfused with Ringer alone. The ratio of Lp can be accounted for in terms of a 1.60-fold increase in water viscosity between 22-25 and 5-8 degrees C. The results conform to the hypothesis that the structure of the principal pathway for water across the capillary wall is invariant with temperature; models of the water pathway that imply a change in the number of pathways or a change in pathway structure with temperature are incompatible with these results. Temperature gradients across the tissue are negligible in these experiments; calculations show that in the presence of temperature gradients, which occur during tissue cooling or rewarming, transcapillary water flows due to thermoosmosis are likely to occur.