A micro-crosslinked amphoteric hydrophobic association copolymer as high temperature-and salt-resistance fluid loss reducer for water-based drilling fluids

During ultradeep oil and gas drilling,fluid loss reducers are highly important for water-based drilling fluids,while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtration performance remains a challenge.Herein,a micro-crosslinked amphoteric hydrophobic association copolymer(i.e.,DADC)was synthesized using N,N-dimethyl acrylamide,diallyl dimethyl ammonium chloride,2-acrylamido-2-methylpropane sulfonic acid,hydrophobic monomer,and pentaerythritol triallyl ether crosslinker.Due to the synergistic effects of hydrogen bonds,electrostatic interaction,hydrophobic association,and micro-crosslinking,the DADC copolymer exhibited outstanding temperature-and salt-resistance.The rheological experiments have shown that the DADC copolymer had excellent shear dilution performance and a certain degree of salt-responsive viscosity-increasing performance.The DADC copolymer could effectively adsorb on the surface of bentonite particles through electrostatic interaction and hydrogen bonds,which bring more negative charge to the bentonite,thus improving the hydration and dispersion of bentonite particles as well as the colloidal stability of the drilling fluids.Moreover,the drilling fluids constructed based on the DADC copolymer exhibited satisfactory rheological and filtration properties(FLHTHP=12 m L)after aging at high temperatures(up to200℃)and high salinity(saturated salt)environments.Therefore,this work provided new insights into designing and fabricating high-performance drilling fluid treatment agents,demonstrating good potential applications in deep and ultradeep drilling engineering.

Preparation of a functional fracturing fluid with temperature-and salt-resistance,and low damage using a double crosslinking network

Fracturing fluids(FFs)have been widely used to stimulate the tight reservoir.However,current FFs will not only lose their rheological property at high temperatures and high salt but also show an incomplete gel-breaking property.Herein,a double crosslinking network FF with pretty superiorities in rheology and low damage to the core was constructed by introducing both physical crosslinking and chemical crosslinking into the system.The construction of double crosslinking networks enhanced the rheology of this functional FF.The particle sizes of gel-breaking fluids are mainly distributed in 1.0e10,000 nm;furthermore,for every 10,000 mg/L increase in salinity,the particle size of the gel-breaking fluid is decreased by almost half.The adsorption capacity(<1.0 mg/g)gradually decreased with the increase of salinity at 20℃.Moreover,the adsorption of gel-breaking fluids on the rock decreased first and then kept stable with temperature increasing at a salinity of ≤30,000 mg/L,however,showed the opposite trend at 40,000 mg/L.The results of rheology,particle size,static adsorption,and core damage showed that this functional FF could be an alternative for the stimulation of a tight reservoir with high temperature and recycling of produced water with high salinity.

Strigolactones modulate cotton fiber elongation and secondary cell wall thickening

Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.

Rheological properties and concentration evolution of thickened tailings under the coupling effect of compression and shear

Cemented paste backfill(CPB)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPB technology.However,difficult flocculation and substandard concentrations of thickened tailings often occur.The rheological properties and concentration evolution in the thickened tailings remain unclear.Moreover,traditional indoor thickening experiments have yet to quantitatively characterize their rheological properties.An experiment of flocculation condition optimization based on the Box-Behnken design(BBD)was performed in the study,and the two response values were investigated:concentration and the mean weighted chord length(MWCL)of flocs.Thus,optimal flocculation conditions were obtained.In addition,the rheological properties and concentration evolution of different flocculant dosages and ultrafine tailing contents under shear,compression,and compression-shear coupling experimental conditions were tested and compared.The results show that the shear yield stress under compression and compression-shear coupling increases with the growth of compressive yield stress,while the shear yield stress increases slightly under shear.The order of shear yield stress from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Under compression and compression-shear coupling,the concentration first rapidly increases with the growth of compressive yield stress and then slowly increases,while concentration increases slightly under shear.The order of concentration from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Finally,the evolution mechanism of the flocs and drainage channels during the thickening of the thickened tailings under different experimental conditions was revealed.

Effect of Synthetic Conditions and Thickener Formulation on the Rheological and Tribological Properties of Polypropylene Grease

Polypropylene(PP)grease holds great potential for special industrial applications.In this study,synthetic conditions,thickener content,and the ratio of two different molecular weight PPs were investigated systematically using a rheometer,scanning electron microscope,X-ray diffraction,Fourier transform infrared spectrometer,oscillating tribometer,and 3D surface profiler measurements.The results showed that suitable synthetic conditions are two quenching cycles,and the synthetic temperature and time is 240℃for 12 h.The rheological analysis showed that thickener content and different proportions of the two PP molecular weights have a significant influence on the rheological properties of PP grease.High molecular weight PP(H-PP)has a stronger thickening ability than low molecular weight PP(L-PP).The higher the amount of H-PP in the fixed thickener content or the higher the thickener content with a specific proportion,the higher the viscoelasticity of PP grease.The tribological performance is related to the rheological properties.The proportion of two different molecular weight PPs in the thickener content should be appropriate;excessive H-PP content leads to lubrication failure.

Experimental study on workability and permeability of sandy soils conditioned with thickened foam

Water spewing and muck plugging often occur during earth pressure balance(EPB)shield machines tunnelling in water-rich sandy strata,even though the conventional foam has been employed to condition sandy soils.In this study,a novel thickened foaming agent suitable for EPB shield tunnelling in water-rich sandy strata is developed.In contrast to conventional foam-conditioned sands,the thickened foam-conditioned sand has a low permeability due to the consistent filling of soil pores with the thickened foam,and the initial permeability coefficient decreases by approximately two orders of magnitude.It also exhibits a suitable workability,which is attributed to the enhanced capability of the thickened foam to condition sandy soils.In addition,the effect of concentration on the stability of the foam is explained by the Gibbs-Marangoni effect,and conditioning mechanisms for the thickened foam on sands are discussed from the evolution of foam bubbles.

Thickening progression mechanism of silica fume-oil well cement composite system at high temperatures

This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C)in order to provide a theoretical guidance for the rational application of silica fume in the cementing engineering.Results showed that silica fume seldom affected the thickening progression of oil well cement slurry at 110-120.C,but when temperature reached above130.C,it would aggravate the bulging degree of thickening curves and significantly extend the thickening time,meanwhile causing the abnormal“temperature-based thickening time reversal”and“dosage-based thickening time reversal”phenomena in the range of 130-160.C and 170-180.C respectively.At 130-160.C,the thickening time of oil well cement slurry was mainly associated with the generation rate of calcium hydroxide(CH)crystal.The introduced silica fume would be attracted to the cement minerals'surface that were hydrating to produce CH and agglomerate together to form an“adsorptive barrier”to hinder further hydration of the inner cement minerals.This“adsorptive barrier”effect strengthened with the rising temperature which extended the thickening time and caused the occurrence of the“temperature-based thickening time reversal”phenomenon.At 170-180.C,the pozzolanic activity of silica fume significantly enhanced and considerable amount of C-S-H was generated,thus the“temperature-based thickening time reversal”vanished and the“dosage-based thickening time reversal”was presented.

Analysis of thermal management and anti-mechanical abuse of multi-functional battery modules based on magneto-sensitive shear thickening fluid

Electric vehicles(EVs)have garnered significant attention as a vital driver of economic growth and environmental sustainability.Nevertheless,ensuring the safety of high-energy batteries is now a top priority that cannot be overlooked during large-scale applications.This paper proposes an innovative active protection and cooling integrated battery module using smart materials,magneto-sensitive shear thickening fluid(MSTF),which is specifically designed to address safety threats posed by lithium-ion batteries(LIBs)exposed to harsh mechanical and environmental conditions.The theoretical framework introduces a novel approach for harnessing the smoothed-particle hydrodynamics(SPH)methodology that incorporates the intricate interplay of non-Newtonian fluid behavior,capturing the fluid-structure coupling inherent to the MSTF.This approach is further advanced by adopting an enhanced Herschel-Bulkley(H-B)model to encapsulate the intricate rheology of the MSTF under the influence of the magnetorheological effect(MRE)and shear thickening(ST)behavior.Numerical simulation results show that in the case of cooling,the MSTF is an effective cooling medium for rapidly reducing the temperature.In terms of mechanical abuse,the MSTF solidifies through actively applying the magnetic field during mechanical compression and impact within the battery module,resulting in 66%and 61.7%reductions in the maximum stress within the battery jellyroll,and 31.1%and 23%reductions in the reaction force,respectively.This mechanism effectively lowers the risk of short-circuit failure.The groundbreaking concepts unveiled in this paper for active protection battery modules are anticipated to be a valuable technological breakthrough in the areas of EV safety and lightweight/integrated design.

Modeling industrial thickener using computational fluid dynamics(CFD),a case study:Tailing thickener in the Sarcheshmeh copper mine

Separation of particles from liquid in the large gravitational tanks is widely used in mining and industrial wastewater treatment process.Thickener is key unit in the operational processes of hydrometallurgy and is used to separate solid from liquid.In this study,population balance models were combined with computational fluid dynamics(CFD)for modeling the tailing thickener.Parameters such as feed flow rate,flocculant dosage,inlet solid percent and feedwell were investigated.CFD was used to simulate the industrial tailing thickener with settled bed of 120 m diameter which is located in the Sarcheshmeh copper mine.Important factor of drag force that defines the rake torque of rotating paddles on the bed was also determined.Two phases turbulence model of Eulerian/Eulerian in accordance with turbulence model ofκ-ε.was used in the steady-state.Also population balance model consists of 15 groups of particle sizes with Luo and Lehr kernel was used for aggregation/breakage kernel.The simulation results showed good agreement with the operational data.

Numerical study of flocculation settling and thickening of whole-tailings in deep cone thickener using CFD approach

Deep cone thickener (DCT) is the key equipment in cemented paste backfill (CPB), so it is essential to study the flocculation settling and thickening characteristics of the whole-tailings in DCT. Coupled with population balance model (PBM), computational fluid dynamics (CFD) was used to study the characteristics, namely particle size distribution (PSD) and underflow concentration in DCT. Based on actual production, the effects of rake rotational speed, feed rate and tailings slurry concentration were simulated and analyzed in a certain range. The PSD varied with rake rational speed, feed rate and tailings slurry concentration almost in the same trend, but the influence of feed rate was less than that of rake rational speed and tailings slurry concentration. The underflow concentration increased at first and then declined with rake rational speed and feed rate, but it rose and fell with the tailings slurry concentration. Finally, the optimal key parameters on the flocculation settling and thickening of the whole-tailings in DCT were obtained: rake rotational speed of 17 r/min, feed rate of 3.25 m^3/h and tailings slurry concentration of 20%, giving the reference values to the industrial production in Baishitamu Copper Mine.

Dynamic simulation of pilot thickener operation using phenomenological model with results validation for continuous and discontinuous tests

The phenomenological theory of sedimentation-thickening processes predicts the settling behavior of a flocculated suspension in dependence of two functions, the batch flux density function and the effective solid stress. These functions were determined using batch settling tests. The governing equations for sedimentation were then solved numerically for these functions and the predictions were compared to the experimental results from pilot scale thickener tests. Firstly, the continuous tests were performed in the plexiglass pilot thickener at different feed flow rates and discharge rates and the solid volume fraction of discharge, the bed height and the time were recorded for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of continuous tests and the results of dynamic simulation. Secondly, the discontinuous tests were performed in the plexiglass pilot thickener at different feed flow rates with a discharge rate of zero. The bed formation rate was determined for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of discontinuous tests and the results of simulation.

Preparation, characterization and salt-resistance of a coal based super absorbent composite

Potassium humate was extracted from brown coal. A novel super absorbent composite, poly （acrylic acid-co-acryla- mide）/potassium humate （PAA-AM/KHA）, was prepared by graft polymerization of acrylic acid, acrylamide and coal based potassium humate using N, N＇-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator. The effects of reaction temperature, degree of neutralization of the poly （acrylic acid） and the amounts of crosslinker, initiator and potassium humate were investigated. Salt resistance tests were also carded out. The composite prepared under optimal conditions had a potassium bumate content of 10% and exhibited a water absorption of 770 g/g in distilled water, and 349, 286 and 41 gig in 0.5 mol/L KC1, MgC12 and A1CI3 solutions respectively. The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly （acrylic acid-co-acrylamide） because of the collaborative effect of functional groups of the coal based potassium humate. The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy. Introduction of potassium humate into the poly （acrylic acid-co-acrylamide） structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments. The salt resisting property of the composite is improved, production costs are reduced and the growth stimulant effect is still present.

Simulation of a semi-industrial pilot plant thickener using CFD approach

Thickeners are important units for water recovery in various industries. In this study, a semi-industrial pilot plant thickener similar to the tailing thickener of the Sarcheshmeh Copper Mine was simulated by CFD modeling. The population balance was used to describe the particle aggregation and breakup. In this population balance, 15 particle sizes categories were considered. The Eulerian-Eulerian approach with standard k-e turbulence model was applied to describe two phases of slurry flow in the thickener under steady-state condition. The simulation results have been compared with the experimental measurements to validate the accuracy of the CFD modeling. After checking the numerical results, the effect of important parameters such as, feed flow rate, solid percentage in the feed, and solid particle size on the thickener performance was studied. The thickener residence time distribution were obtained by the modeling and also compared with the experimental data. Finally, the effects of feedwell feeding on the average diameter of aggregate and turbulent intensity were evaluated.

A novel associative latex thickener using ethoxylated behenyl methacrylate as functional monomer

Alkali-soluble associative latex thickeners modified with hydrophobic long chain alkyl groups were prepared using common acrylics and varying amount of a functional monomer,ethoxylated behenyl methacrylate(BEM),through emulsion polymerization.It was found that the size of the emulsion particle became larger with addition of BEM.The light transmittance of the thickener latex sharply increased with pH varied from 6 to 7.The associative latex thickener manifested a higher viscosity when solids in the latex thickeners were kept at 0.5 wt%or higher,and the optimal amount of BEM was found to be around 2.5 wt%,or 0.16 mol%.All thickener latexes modified with BEM have better shearing resistance than the BEM-free thickener.

Application of response surface methodology and central composite rotatable design for modeling the influence of some operating variables of the lab scale thickener performance

This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation circuit.Four thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on CCRD.The ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,Iran.The underflow solid percent and bed height were expressed as functions of four operating parameters of thickener.Predicted values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.

DETERMINING THICKENER UNDERFLOW CONCENTRATION AND UNIT AREA

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Changes in underflow solid fraction and yield stress in paste thickeners by circulation

The trouble-free and efficient operation of paste thickeners requires an optimal design and the cooperation of each component.When underflow discharging is suspended,alleviating the vast torque that the remaining solids within the thickeners may place on rakes mainly lies in the circulation unit.The mechanism of this unit was analyzed,and a mathematical model was developed to describe the changes in underflow solid content and yield stress.The key parameters of the circulation unit,namely,the height and flow rate,were varied to test its performance in the experiments with a self-designed laboratorial thickening system.Results show that the circulation unit is valid in reducing underflow solid fraction and yield stress to a reasonable extent,and the model could be used to describe its efficiency at different heights and flow rates.A suitable design and application of the circulation unit contributes to a cost-effective operation of paste thickeners.

Numerical simulation and optimization of red mud separation thickener with self-dilute feed

In order to acquire the flow pattern and investigate the settling behavior of the red mud in the separation thickener,computational fluid dynamics(CFD),custom subroutines and agglomerates settling theory were employed to simulate the three-dimensional flow field in an industrial scale thickener with the introduction of a self-dilute feed system.The simulation results show good agreement with the measurement onsite and the flow patterns of the thickener are presented and discussed on both velocity and concentration field.Optimization experiments on feed well and self-dilute system were also carried out,and indicate that the optimal thickener system can dilute the solid concentration in feed well from 110 g/L to 86 g/L which would help the agglomerates' formation and improve the red mud settling speed.Furthermore,the additional power of recirculation pump can be saved and flocculants dosage was reduced from 105g/t to 85g/t in the operation.

The Effect of Food Thickeners on the Bitterness and Dissolution of Amlodipine Besilate Powder When Co-Administered with Thickeners to Patients with Dysphagia

Purpose: The present research was performed to evaluate the effect of food thickeners on the bitterness and dissolution of bitter drugs when co-administered to patients with dysphagia. Methods: Amlodipine besilate (AMPB) powder was used as a model drug. Starch- and xanthan gum-based food thickeners were examined, with swallowing-aid jelly as a reference. The line-spread test (LST), texture prolife analysis (TPA) were done firstly. In related to AMPB powder mixed with food thickeners solution, a conventional dissolution test simulating the oral cavity was performed, the amlodipine (AMP) concentration and taste sensor output for dissolved medium versus time profiles were developed. The dissolution test at pH 1.2 and 4.5, representing typical gastric conditions for younger or elderly people, was performed in two kinds of thickener solution and swallowing-aid jelly those were mixed with AMPB powder. Results: LST demonstrated that xanthan gum-based food thickeners fulfilled the requirements for patients with dysphagia but that starch-based food thickeners did not. In TPA, hardness and adhesiveness decreased proportionally as the concentration increased for both kinds of food thickener. Conventional dissolution test simulating oral cavity demonstrated the following bitterness ranking: xanthan gum-based food thickener Conclusion: Although xanthan gum-based food thickeners were successful in masking the bitterness of AMP, they may reduce its bioavailability in humans. The 7.1 and 4.7 (w/v) % starch-based thickener show bitterness inhibition under simulated oral cavity conditions and complete dissolution of AMP under simulated gastric conditions.

Production and Properties of a Thickener with Ability of Suspending Sand

To overcome the shortcomings of pouring sands, a thickener with the ability to suspend sands was developed. It is mixed with sands to form densified slurry, and can insure the sands against deposition, jamming pipelines and de- hydration. The chemical structure of the thickener is introduced in this paper and the production process is studied. The main processes include immersion, decomposition, dilution and addition of additives. In order to produce a thickener with high viscosity to suspend sands, key factors must be controlled in each process: the immersion time is 2 h; the mass fraction of formaldehyde is 0.01% and mass of NaCO3 accounts for 15% of dry material; the water temperature is 65 ℃ in summer and 72 ℃ in winter and the decomposition time is 2 h in the reaction; the densified decomposition so- lution should be diluted to 1% mass fraction; the additives of calcium ions and pH indicators must be added to the di- luted liquid; the mass fraction of CaCl2 is 0.048% and the pH value of the solution is 7.5. The thickener is a gel with three-dimensional network structure, a liquid with non-Newtonian behaviour and the characteristics of pseudo-plastic material, a solution with little resistance and the ability to revive its oral primary viscosity. It has been successfully ap- plied in Shendong Mines and has great value and wide-spread prospective use.