Добірка наукової літератури з теми "MZVI SUSPENSIONS FIELD INJECTION"

One of the main technical problems faced during field-scale injections of iron microparticles (mZVI) for groundwater nanoremediation is related to their poor colloidal stability and mobility in porous media. In this study, a shear-thinning gel, composed of a mixture of two environmentally friendly biopolymers, i.e., guar gum and xanthan gum, was employed to overcome these limitations. The slurry rheology and particle mobility were characterized by column transport tests. Then, a radial transport experiment was performed to mimic the particle delivery in more realistic conditions. The gel, even at a low polymeric content (1.75 g/L), proved effective in enhancing the mobility of high concentrated mZVI suspensions (20 g/L) in field-like conditions. The high radius of influence (73 cm) and homogeneous iron distribution were achieved by maintaining a low injection overpressure (<0.4 bar). Based only on the information derived from column tests, the MNMs 2018 software (Micro- and Nanoparticle transport, filtration, and clogging Model-Suite) was able to predict the particle distribution and pressure build-up measured in the radial domain. Experimental and simulated results showed good agreement, thus proving that a simplified experimental-modeling procedure based on 1D column tests could be used to effectively upscale the slurry behavior to more representative scales, e.g., radial domains.

The flocculation of an unstabilized suspension of fine ceramic particles is advanced as the explanation for the formation of cracks in a “liquid” suspension. The development of cracks was observed several minutes after reheating wax-based ceramic moldings above the melting point of the wax and was accompanied by phase separation of the wax from the molding. Calculations of the acceleration of particles under London dispersion forces in a viscous fluid show the “time to impact” as a function of initial separation distance, fluid viscosity, and particle size. This is compared with the intercollision time calculated from classical flocculation theory, and it is shown that for crowded suspensions initial interparticle distances are such that the London force field cannot be neglected. Methods of preventing the flocculation are described.

Particle and electrode surfaces were altered to examine the effects on the electrorheological response of barium titanate/silicone oil suspensions. Unmodified suspensions exhibited nonlinear conduction. The dynamic yield stresses scaled as En, where n<2 at all electric field frequencies, and the current had substantial harmonic content, a hallmark of nonlinear conduction. Modifying the particle surfaces did not affect these nonlinear responses. Casting polymers on the electrode surfaces changed the responses. With polymer coatings, the dynamic yield stresses scaled as En, where n≥2 at some frequencies and increased with coating thickness. With coated electrodes, the current harmonic contents were significantly decreased. These results suggest that nonlinear conduction in ER suspensions is associated with charge injection at the electrode/liquid interface.

The microstructures of injection-molded short fiber composites, involving fiber orientation and fiber concentration, strikingly influence flow behaviors and mechanical properties. Through the use of certain commercial software, reported numerical predictions of fiber orientation for the shell–core structure have been obtained to date. However, no work has been done on fiber concentration prediction available in processing simulations. In the theoretical field of suspension rheology, the suspension balance (SB) model has proven successful in capturing particle migration behavior under the simple Couette shear flow of “spherical” particle suspension, hence the attempt to verify the SB model applied in the “like-rod” suspensions. To predict flow-induced variations of fiber concentration, the SB model is implemented in 3-D-injection molding simulation with more general flows. It is remarkable for the shell–core structure is explored to reflect the relationship between fiber orientation and fiber concentration.

Active fluids exhibit spontaneous flows with complex spatiotemporal structure, which have been observed in bacterial suspensions, sperm cells, cytoskeletal suspensions, self-propelled colloids, and cell tissues. Despite occurring in the absence of inertia, chaotic active flows are reminiscent of inertial turbulence, and hence they are known as active turbulence. Here, we survey the field, providing a unified perspective over different classes of active turbulence. To this end, we divide our review into sections for systems with either polar or nematic order, and with or without momentum conservation (wet or dry). Comparing to inertial turbulence, we highlight the emergence of power-law scaling with either universal or nonuniversal exponents. We also contrast scenarios for the transition from steady to chaotic flows, and we discuss the absence of energy cascades. We link this feature to both the existence of intrinsic length scales and the self-organized nature of energy injection in active turbulence, which are fundamental differences from inertial turbulence. We close by outlining the emerging picture, remaining challenges, and future directions.

Laboratory tests to establish the influence of the material and particle size distribution composition of hydrogenous ores on the intensity of sedimentation of colmatants during in-situ leaching have established that the main reason for loss of productivity of technological wells during in-situ leaching of hydrogenous ores of the Khiagda ore field deposits is colmatation of their near-filter zone. The greatest influence is exerted by mechanical and chemical colmatation, in the process of which fine mechanical suspensions accumulate in the near-filter zone and products of chemical reactions occurring during leaching [4; 9–12]. It has been determined that the most effective way to eliminate mechanical bridging is pneumatic-pulse processing of the filter zone of technological wells, and the use of processing wells with hydrochloric acid and ammonium bischofite allows to remove most of the chemical bridging agents deposited on the structural elements of the well reinforcement [2, 3]. The conducted research makes it possible to improve the regulation of repair and restoration works when treating technological wells in the process of carrying out production works at the hydrogenous deposits of the Khiagda ore field. The results of applying technical solutions to restore the serviceability of injection and injection wells are given in this article

The article is devoted to an example of the sonoluminescence spectroscopy use, which was previously known as a method for analyzing substances from the characteristic spectra of their sonoluminescence only in true solutions, for carrying out a similar analysis of substances contained in insoluble nanoparticles in colloidal suspensions. The solutions sonolysis, that is, their irradiation with ultrasound, is accompanied by the formation of cavitation bubbles that vibrate radially at the frequency of the ultrasonic field. Volatile components of the solution enter the bubbles, evaporating from the liquid-gas interface; nonvolatile components can penetrate into the bubble as a result of the injection of solution nanodroplets into the gas phase, which occurs during intense bubble movements accompanied by their deformation. In a nonequilibrium plasma periodically forming in cavitation bubbles, destruction occurs, as well as collisional excitation of these components, followed by luminescence. It has been shown that this mechanism of sonoluminescence also operates in colloidal suspensions, where substances are present in the form of nanoparticles with sizes less than 50 nm. Such nanoparticles penetrate into moving cavitation bubbles, without destroying them, as part of nanodroplets, and then undergo decomposition in bubble plasma with the excited particles generation as emitters of characteristic sonoluminescence. In this work, we synthesized colloidal suspensions in dodecane of porous SiO2 nanoparticles containing adsorbed Ru(bpy)3Cl2 and CuSO4 salts. During moving single-bubble sonolysis for these suspensions, characteristic emission spectra of Ru and Cu atoms, SiO molecules, and Ru(bpy)3 ions suitable for sonoluminescence spectroscopic analysis were recorded. By comparing the experimental and calculated (at different temperatures) luminescence spectra of Ru atoms, we estimated the electron temperature attained upon acoustic compression of single bubble in colloidal suspension in dodecane: Te = 7000 K.

Summary In this paper, we incorporated a kinematic proppant transport model for spherical suspensions in hydraulic fractures developed by Dontsov and Peirce (2014) in a pseudo-3D hydraulic-fracture simulator for multilayered rocks to capture a different proppant transport speed than fluid flow and abridged fracture channel by highly concentrated suspensions. For pressure-driven proppant transport, the bridges made of compact proppant particles can lead to both proppant distribution discontinuity and increased fracture aperture and height because of the higher pressure. The model is applied to growth of a fracture from a vertical well, which can contain thin-bedded intervals and more than one opened hydraulic-fracture interval, because the fracture plane extends in height through layers with contrasts in stress and material properties. Three numerical examples demonstrate that a loss of vertical connectivity can occur among multiple fracture sections, and proppant particles are transported along the more compliant layers. The proppant migration within a narrow fracture in a thin soft rock layer can result in bridging and formation of a proppant plug that strongly limits fluid speed. This generates an increase of injection pressure associated with fracture screenout, and these screenout events can emerge at different places along the fracture. Next, because of the lack of pretreatment geomechanical data, the values of layer stress and leakoff coefficient are adjusted for a field case so that the varying bottomhole pressure and fracture length are in line with the field measurements. This paper provides a useful illustration for hydraulic-fracturing treatments with proppant transport affected by and interacting with reservoir lithological complexities.

Fusarium crown rot (FCR), caused by Fusarium species, is a serious soilborne fungal disease in many wheat growing regions in the world. A reliable FCR assessment method is essential for germplasm screening and host resistance studies. Here, we report a new assay in which we inoculated wheat seedlings grown in a glasshouse for FCR by injecting spore suspensions into the seedling stems. The effects of inoculum concentration and injection time points on disease severity were investigated. Of different treatments, the injection of 107 macroconidia/ml suspension at one leaf and one heart stage gave best results. A collection of 92 emmer-derived hexaploid bread wheats, 43 barley germplasms, and four wheat genotypes with known resistance levels to FCR was used to validate this new method. Repeatability of the two trials in the validation experiments was high (r = 0.97, P < 0.01). Two emmer-derived hexaploid bread wheat and three Chinese barley germplasms showed consistent resistance to FCR in multiple rounds of selection. The short timeframe of this assay for phenotypic screening makes it a valuable tool to eliminate germplasms with undesirable susceptibility to FCR at seedling stage before costly field assays.

Summary A microbial profile modification (MPM) process consisting of sequential injection of spores and nutrient was designed and tested for the first time in a carbonate reservoir. An 80-acre, inverted five-spot pattern located in Eunice Monument South Unit in Lea County, New Mexico, was chosen for the field trial. Injection profiles taken before and after the microbial treatment showed that the thief zones were plugged by the biofilm resulting in fluid diversion. Injection profiles also indicated that the biofilm which formed in the reservoir remained stable for more than 8 months. The results of the field trial proved the viability of the MPM technology. Introduction Field History and Geology. The Eunice Monument field is located on the northwestern edge of the Central Basin Platform in southeastern Lea County, New Mexico, approximately 15 miles southwest of the city of Hobbs. The field was discovered on March 21, 1929 with the majority of field development occurring from 1934 through 1937. The well development in the Eunice Monument South Unit (EMSU) was on 40-acre spacing. In May 1937, primary oil production peaked. The field was produced under primary means until unitization of the field occurred in February 1985. Oil was produced primarily from dolomites of the Permian (Guadalupian) -aged Grayburg Formation. A minor amount of production was also from the overlying lower Queen (Penrose) Formation. Underlying the Grayburg is the San Andres Formation, a waterdrive reservoir. The Grayburg is at an average depth of about 3,700 ft and averages 250 ft thick with a reservoir temperature of 90°F. It is subdivided into six zones based on relatively thin, generally impermeable sandstone. Porosity ranges up to approximately 20% with a fieldwide average of 9.4%. The permeability range is approximately 0.01 to 75 md with an average of 13 md. The reservoir is very heterogeneous with the DP coefficient of about 0.85. Waterflood pattern development of the unit was 80-acre five-spot, and the initial injection was started in November 1986 with full-scale injection underway by June 1988. The early water injection rate was limited to between 500 and 700 B/D per injector, and later the rates were increased from 500 to 2,500 B/D per well. The original oil in these formations was estimated to be 671.5 MMSTBO, and the cumulative recovery to date has been approximately 127 MMSTBO. The crude oil is light with a gravity of 32°APl, and the reservoir brine contains substantial amounts of calcium and magnesiums ions. The brine compositions are listed in Table 1. Microbial Profile Modification Process. In our previous papers,1,2 we presented the basic concept and some data on a microbial profile modification (MPM) process. The microbe used for this process is Salton-1, a gram-positive, rod-shaped bacterium with a width of about 0.2 to 0.3 ?m and a length of 0.5 to 1.0 ?m. It closely resembles the species Bacillus licheniformis,3 and is a facultative anaerobic mesophile. More details of this process are given elsewhere.1 In this paper, the laboratory design and implementation of the MPM process in the EMSU field are presented. Experiment All tube and core tests were conducted at 90°F. To simulate reservoir environment, test tubes containing inoculum, were anaerobically incubated. For core tests, fired Berea cores with dimensions of 2.54 cm diam×30 were used. In some tests, reservoir plugs of 2.5 cm diam×5 to 6 cm length were used. The brine permeability of all Berea cores was about 1,000 md to mimic the thief zones. The specific values are noted in the figures. All nutrient media and spore suspensions prepared for the core and tube tests were made in injection water unless otherwise stated. We used a backpressure of 1,500 psi in the core tests to remove any spurious effect of the gas produced by the microbial activity on permeability reduction. The Berea cores had two pressure taps, equally spaced along the core. The Hassler type of core holder was used for the reservoir plugs. Generally, a 1-PV of 107 (colony forming unit per mL) of spore suspension was followed by an equal amount of nutrient solution, and the core containing inoculum was incubated or shut in for a specified period, followed by post-brineflush. The injection rate was 10 mL/h. Thereafter, some cores containing biofilm were further incubated for stability test. Any deviation from these procedures has been specified as appropriate. The fermented medium was microscopically examined to check the viability of the microbes and also the stage of their life cycle. In addition, viable counts or enumeration were done on agar plates. The stability of biofilm was assessed by hand shaking of the tube, and the biofilm was termed stable if it did not break upon shaking. Field water analysis was performed with an ion chromatography unit (IC). Eluants were made with de-gassed DI water and filtered through a 0.22 ?m filter. Helium gas was initially bubbled through the eluant and the eluant was kept under the helium blanket throughout the experiment. The injection and the produced water samples were passed through a cation exchange (SCX) column to remove cations prior to the chromatographic runs. Also, the guard and analytical columns were preconditioned prior to the sample runs to establish a stable baseline, and were tested with known samples for concentration and retention time. For anion analysis, a conductivity detector with AS4A-SC analytical and guard columns, as well as an anion membrane suppressor, was used. The eluant was a mixture of 1.8 mM of Na2CO3 and 1.7 mM of NaHCO3 . The membrane suppressor solution was 50 mN of H2SO4. Inductively coupled plasma (ICP) spectroscopy was used for the cation analysis.

Magneto-rheologiacal Fluid (MRF), suspensions of polarizable micron size particles, is synthesized from suspensions of iron particles (micron and nano size) in phosphate buffered saline (PBS). The iron particles have been surface coated using atom transfer radical polymerization (ATRP) with various polymers, such as poly(N-isopropylacrylamide) (poly(NIPAAm)), and poly(acrylamide) (poly(AAm)). The surface grafted polymer has been characterized using differential scanning calorimetry (DSC), and properties of resulting fluid have been measured using a rheometer. A mathematical model is developed to explore the force induced by the particles on the neighboring tissue under externally applied magnetic field. This force results in the damage of the tumor cell lines and trigger the immune system response. The effect of MRF on primary and metastasized tumor growth were evaluated by using an orthotopic murine breast cancer model (4T1). Tumors were evaluated by growth measurements and histological changes following injection of MRF or carrier fluid alone into the tumor and the effects of subsequent application of a magnetic field to the site. Results indicate slowed tumor growth and increased dendritic cell activation with this therapy and they are encouraging.

In this article we report on a planar miniaturized dielectrophoretic (DEP) microfluidic device developed for the purpose of continuous fractionation and purification of sample suspensions of microscopic particles or biological cells, employing specially shaped nonuniform (isomotive) electric fields. The device integrates three fully functional and distinct sub-units consisting of 1) sheath and sample injection ports, arranged to achieve hydrodynamic focusing of the cell stream; 2) the DEP fractionation region and 3) two sample collection ports. In the DEP fractionation region, the magnitude of the field induced DEP force acting on the particle is essentially constant and independent of the particle’s position and furthermore only dependent on the intrinsic polarization response of the particle, for identical sized particles. The operation and performance in terms of sample throughput, separation efficiency and repeatability of the device was evaluated using test microscopic sized dielectric particles and biological particles, including cancerous cell lines.

Endophytes were isolated from 16.7% of surface-disinfested seeds and 100% of stems and roots of field-growth plants. Strains from Israel with broad-spectrum in vitro antibiosis were mainly Bacillus spp., and some were chitinolytic. Following dipping of cut cotton roots into suspensions of these strains, endophytes were detected up to 72 days later by isolation and by autoradiograms of 14C-labelled bacteria. Selected endophytes exhibited biological control potential based on significant reductions in disease severity on cotton inoculated with Rhizoctonia solani or Fusarium oxysporum f. sp. vasinfectum as well as control of Sclerotium rolfsii on bean. Neither salicylic acid nor chitinase levels increased in plants as a result of endophytic colonization, suggesting that the observed biocontrol was not accounted for by PR protein production. Some biocontrol endophytes secreted chitinolytic enzymes. Model endophytic strains inoculated into cotton stems via stem injection showed only limited movement within the stem. When introduced into stems at low concentrations, endophytes increased in population density at the injection site. After examining several experimental and semi-practical inoculation systems, seed treatment was selected as an efficient way to reintroduce most endophytes into plants.