A Novel Fracturing Fluid with High-Temperature Resistance for Ultra-Deep Reservoirs

Ultra-deep reservoirs play an important role at present in fossil energy exploitation.Due to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do not produce satisfactory results when conventional fracturing fluids with a low pumping rate are used.In response to the above problem,a fracturing fluid with a density of 1.2~1.4 g/cm^(3)was developed by using Potassium formatted,hydroxypropyl guanidine gum and zirconium crosslinking agents.The fracturing fluid was tested and its ability to maintain a viscosity of 100 mPa.s over more than 60 min was verified under a shear rate of 1701/s and at a temperature of 175℃.This fluid has good sand-carrying performances,a low viscosity after breaking the rubber,and the residue content is less than 200 mg/L.Compared with ordinary reconstruction fluid,it can increase the density by 30%~40%and reduce the wellhead pressure of 8000 m level reconstruction wells.Moreover,the new fracturing fluid can significantly mitigate safety risks.

Performance Assessment on Corrosion Resistance of Refractory Materials Based on High-temperature Machine Vision Technology

Refractory materials,as the crucial foundational materials in high-temperature industrial processes such as metallurgy and construction,are inevitably subjected to corrosion and penetration from high-temperature media during their service.Traditionally,observing the in-situ degradation process of refractory materials in complex high-temperature environments has presented challenges.Post-corrosion analysis are commonly employed to assess the slag resistance of refractory materials and understand the corrosion mechanisms.However,these methods often lack information on the process under the conditions of thermal-chemical-mechanical coupling,leading to potential biases in the analysis results.In this work,we developed a non-contact high-temperature machine vision technology by the integrating Digital Image Correlation(DIC)with a high-temperature visualization system to explore the corrosion behavior of Al2O3-SiO2 refractories against molten glass and Al2O3-MgO dry ramming refractories against molten slag at different temperatures.This technology enables realtime monitoring of the 2D or 3D overall strain and average strain curves of the refractory materials and provides continuous feedback on the progressive corrosion of the materials under the coupling conditions of thermal,chemical,and mechanical factors.Therefore,it is an innovative approach for evaluating the service behavior and performance of refractory materials,and is expected to promote the digitization and intelligence of the refractory industry,contributing to the optimization and upgrading of product performance.

High-temperature resistant polymer nanocomposites with exfoliated organic-modified montmorillonite nanosheets strongly adsorbed on polymer chains

It has been demonstrated that almost all polymer-clay nanocomposites show higher temperature stability than that of pure polymer, which is attributed to the active exfoliated clay nanosheet firmly adsorbed onto the polymer chains, due to polerization and nucleation effect, the clay nanosheets could protect the polymer chains from destroying. To prove such mechanism, the water-soluble polymer nanocomposites(AAA/SLS-MMT) were synthesized by the in-situ polymerization of 2-acrylamide-2-methyl-propane sulfonic acid, acrylamide, 4-acryloylmorpholine, and organically modified montmorillonite. The techniques of nuclear magnetic resonance, atomic force microscopy and scanning electron microscopy etc., clearly characterized the successful synthesized of sample's structure, the exfoliated MMT nanosheet adsorbed polymer chain's scale, and well-dispersed morphology, espectively. The adsorption model, X-ray photoelectron spectroscopy presented the existence of strong adsorption, while molecular simulation calculations first concluded that the strong adsorption energy was-13032.06 kcal/mol. Thermo-gravimetric-analysis proved the temperature of maximum thermal degradation of powder sample(AAA/1.0 wt% SLS-MMT) was over 298℃. After ageing at 180℃ for 4 h, the apparent viscosity of 5 g/L AAA/1.0 wt% SLS-MMT aqueous solution was 326.7 mPa,s, while that of pure polymer(AAA) was only 8.3 mPa,s. This optimized sample has the smallest FLAPIvalue at all test temperatures from 180 to 220℃ in both fresh and salt water based drilling fluid. All the evidences of high temperature resistance indicate that the strong adsorption can enhance the thickness of hydrated shell and adsorption of clay particles in drilling fluid at high temperature. Such mechanism supplied the better way to design high-temperature resistant fluid loss additives for deep and ultra-deep oil and gas formation engineering.

High-temperature Resistance Performance of An Inorganic Adhesive for Concrete Structures Strengthened with CFRP Sheets

Organic epoxy matrices have been widely used in the FRP reinforcing technique, but they have serious disadvantages of poor high-temperature resistance. An inorganic adhesive is invented to replace the organic adhesive. For the inorganic adhesive at normal temperature and different high temperatures, the microstructure and phase composition are investigated by means of X-ray diffraction （XRD） and SEM respectively. Results show that inorganic adhesive can resist at least 600 ℃ high temperature. Fire-resistance performance of inorganic adhesive can meet the requirements of fiber reinforced polymer （FRP） strengthened RC structures.

Micro-analysis of high-temperature oxidation-resistance of a new kind of heat-resistant grid plate in grate-kiln

To further improve the oxidation-resistance of materials and reduce the cost of grid plates in grate-kiln, a new kind of heat-resistant grid plate was developed. The microstructure of this grid plate with a life more than 18 months was studied by XRD, SEM and EDS techniques. The results show that high hardness, high intensity and good impact property make the new kind of heat-resistant grid plate and its oxide film have a higher resistance to deformation and abrasion at 900-1000℃ Besides, small grain size is beneficial to form a complete protective oxide film. The oxide film composed of SiO2 layer, Cr2O3 layer and Fe2O3 layer is rather thin and bonds closely with the backing. The forming of the chemical stable nickel-rich layer increases the density of Cr2O3 layer.

Genetics and Molecular Mapping of a High-Temperature Resistance Gene to Stripe Rust in Seeding-Stage in Winter Wheat Cultivar Lantian 1

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici （Pst）, is a severe foliar disease of common wheat （Triticum aestivum L.） in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene（s） for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 （M169）. Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat （SSR） techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.

Flexural behavior of composite beams after the ultimate limit state externally strengthened with CFRP sheets bonded with high-temperature resistant matrix

In this paper the alkali-activated slag cementitious materials(AASCM)which strength at 600 ℃ is larger than that of AASCM at room temperature,were prepared to paste CFRP sheets to strengthen four simply supported unbonded prestressed composite beams encased circular steel tube truss after ultimate limit state.Test on flexural behavior of these four beams was performed.Moreover,normal section load-bearing capacity of these beams and the curve load-deflection at mid-span were obtained.Experimental results show that it is feasible to strengthen concrete members with CFRP sheets bonded with AASCM.Based on the experimental results and theoretical study,computational method of stiffness is proposed for calculating bending rigidity and normal section load-bearing capacity of concrete simply supported beams strengthened with CFRP sheets bonded with AASCM.Formula of bending rigidity calculation was founded which results are in good agreement with testing data.

High-temperature oxidation behavior of heat resistant stainless steel 1.4828

The kinetic curves of the high-temperature oxidation of austenitic heat resistant stainless steel 1. 4828 at 1 050 ℃ were measured using a weighing method. It is shown that the oxidation curves at 1 050 ℃ followed the parabolic line law, and after 250 h of oxidation, the mass gain was about 80 g/m2. The surface morphology and structure of the oxide layers were studied by scanning electron microscopy and X-ray diffraction. A complicated oxide layer obtained at 1 050 ℃ was mainly composed, from inner to outer, of （FeSi） 3 04, Cr2 03, Fe2 03, and spinel oxides FeCr204 and NiMn204.

A high-temperature resistant and high-density polymeric saturated brine-based drilling fluid

Three high-temperature resistant polymeric additives for water-based drilling fluids are designed and developed:weakly cross-linked zwitterionic polymer fluid loss reducer(WCZ),flexible polymer microsphere nano-plugging agent(FPM)and comb-structure polymeric lubricant(CSP).A high-temperature resistant and high-density polymeric saturated brine-based drilling fluid was developed for deep drilling.The WCZ has a good anti-polyelectrolyte effect and exhibits the API fluid loss less than 8 mL after aging in saturated salt environment at 200°C.The FPM can reduce the fluid loss by improving the quality of the mud cake and has a good plugging effect on nano-scale pores/fractures.The CSP,with a weight average molecular weight of 4804,has multiple polar adsorption sites and exhibits excellent lubricating performance under high temperature and high salt conditions.The developed drilling fluid system with a density of 2.0 g/cm^(3)has good rheological properties.It shows a fluid loss less than 15 mL at 200°C and high pressure,a sedimentation factor(SF)smaller than 0.52 after standing at high temperature for 5 d,and a rolling recovery of hydratable drill cuttings similar to oil-based drilling fluid.Besides,it has good plugging and lubricating performance.

Experimental analysis of HR-120 alloy used for high-temperature fans

High-temperature circulating fans blow 800 ℃ HN protective atmosphere to the surface of the strip as a jet heating power source or suspending source,playing a core role in metal strip continuous annealing furnaces. In this study,several high-temperature alloys were experimentally compared based on their high-temperature mechanical properties,high-temperature creep resistance,and high-temperature oxidation resistance. The results indicate that though the price of HR-120 alloy is only half of Inconel 601,it is suitable for the manufacture of fans that can withstand a high temperature of 800 ℃ given its good creep resistance,high-temperature oxidation resistance,and price advantage.

Effect of La_2O_3 on microstructure and high-temperature wear property of hot-press sintering FeAl intermetallic compound

FeAl intermetallic compound with different contents of rare earth oxide La2O3 addition was prepared by hot pressing the mechanically alloyed powders.Effect of La2O3 on microstructure and high-temperature wear property of the sintered FeAl samples was investigated in this paper.The results showed that 1 wt.% La2O3 addition could refine the microstructure and increase the density of the FeAl intermetallic compound,and correspondingly improved the high-temperature wear resistance.SEM and EDS analyses of the wo...

Corrosion evolution of high-temperature formed oxide film on pure Sn solder substrate

The evolution of morphology, composition, thickness and corrosion resistance of the oxide film on pure Sn solder substrate submitted to high-temperature aging in 150 °C dry atmosphere was investigated. The results indicate that high-temperature aging accelerates the dehydration of Sn(OH)_(4)in the pre-existing native oxide film to form SnO_(2)and facilitates the oxidation of fresh Sn substrate, resulting in the gradual increase in oxide film thickness and surface roughness with prolonging aging time. However, the corrosion resistance of the film initially is enhanced and then deteriorated with an extending aging time. Besides, the formation and evolution mechanisms of the oxide film with aging time were discussed.

Preparation and Thermal Shock Resistance of Mullite Ceramics for High Temperature Solar Thermal Storage

Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testing techniques.The experimental results indicate that sample A3(bauxite/kaolin ratio of 5:5)sintered at 1620℃has the optimum comprehensive properties,with bulk density of 2.83 g·cm^(-3)and bending strength of 155.44 MPa.After 30 thermal shocks(1000℃-room temperature,air cooling),the bending strength of sample A3 increases to 166.15 MPa with an enhancement rate of 6.89%,the corresponding thermal conductivity and specific heat capacity are 3.54 W·(m·K)^(-1)and 1.39 kJ·(kg·K)^(-1)at 800℃,and the thermal storage density is 1096 kJ·kg^(-1)(25-800 mullite ceramics;sintering properties;high-temperature thermal storage;thermal shock resistance).Mullite forms a dense and continuous interlaced network microstructure,which endows the samples high thermal storage density and high bending strength,but the decrease of bauxite/kaolin ratio leads to the decrease of mullite content,which reduces the properties of the samples.

Oxidation resistance of powder metallurgy Ti-45Al-10Nb alloy at high temperature

TiAl alloy with high Nb content,nominally Ti-45Al-10Nb,was prepared by powder metallurgy,and the oxidation resistance at 850,900,and 950℃was investigated.The high-temperature oxidation-resistance mechanism and oxidation dynamics were discussed following the oxide skin morphology and microstructural evolution analysis.The oxide skin structures were similar for 850 and 900℃,with TiO_(2)+Al_(2)O_(3)mixture covering TiO_(2)with dispersed Nb_(2)O_(5).At 950℃,the oxide skin was divided into four sublayers,from the outside to the parent metal:loose TiO_(2)+Al_(2)O_(3),dense Al_(2)O_(3),dense TiO_(2)+Nb_(2)O_(5),and TiO_(2)matrix with dispersed Nb_(2)O_(5).The Nb layer suppressed the outward diffusion of Ti atoms,hindering the growth of TiO_(2),and simultaneously promote the formation of a continuous Al_(2)O_(3)protective layer,providing the alloy with long-term high-temperature oxidation resistance.

High-temperature performance study of chromium-containing stuffing sand for ladles

High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the composition ratio of ladle filler sand and sintering time on the high-temperature compression resistance of chromium-containing stuffing sand in the temperature range of 1 500- 1 600 ℃. The results show that the refractoriness of ladle filler sand w as the low est（ only 1 610 ℃） w hen the composition ratio of chromite sand and silica sand w as 6∶ 4. M oreover,the high-temperature compression resistance w as high w hen the content of chromite sand w as at 70%; the resistance increased w ith increasing sintering time. When the sintering time w as extended at a temperature of 1 600 ℃,the high-temperature compression resistance of ladle filler sand first increased and then decreased after being overburnt.

Junction Pressure Composing MethodCalculating the Total Resistance of Mine Ventilation Network

In mine ventilation network calculation, the total ventilatiou perameters, such as total specific resistance and total natural veutilatiou pressure of an overall mine ventilation system, play an important role on selecting main fan and regulating its operating point. This paper explains the critical effect of network’ s total parameter calculation on the above two aspects and presents a new method, the junction pressure composing method(JPC method), which can be applied to calculate the total resistance.of an overall, complex and multi-fan ventilation network. Based on the total ressistance and airflow rate of main fan, total specific resistance of a natwork is easily calculated. This method gets rid of those shortcomings in the route airflow working mathod(RAW method), greatly improves computing speed and adaptability, and can calculate the total parameters of a mine ventilation network rapidly and conveniently. This method is proved to be correct and reliable by example tests.

In-situ Synthesis and Oxidation Resistance of Sialon/SiC Composite Ceramics Applied as Solar Absorber

Sialon/SiC composites were synthesized in situ from SiC,α-Si_(3)N_(4),AlN,calcined bauxite,quartz and Y_(2)O_(3) via layered buried sintering at different temperatures (1 540-1 640 ℃).The results showed that the O’-sialon/SiC sample with 60 wt% silicon carbide sintered at 1 600 ℃ exhibited excellent mechanical properties,with apparent porosity of 16.01%,bulk density of 2.06 g·cm^(-3),bending strength of 52.63 MPa,and thermal expansion coefficient of 5.83×10-6 ℃^(-1).The oxide film formed on the surface was linked closely to O’-sialon,so the oxide film was not easily broken.After 100 h oxidization,the sample surface was smoother and denser,with oxidation weight gain rate 23.6 mg/cm^(2) and oxidation rate constant 2.0 mg^(2)·cm^(-4)·h^(-1).Therefore,the sample had the excellent high-temperature oxidation resistance.It was confirmed that the in-situ sialon/SiC composites could be a promising candidate for solar absorber owing to its high-temperature oxidation resistance.

Research on material design and high-temperature friction and wear properties of new graphitic steel

To solve the problem of the severe mismatch between the product and roll materials in the preliminary rolling line,a new graphitic steel material was designed,its microstructure and high-temperature friction and wear properties were investigated.Moreover,the feasibility of replacing semi-steel with this new material in the V1 stand roll was studied herein.The results show that the graphitic steel matrix is strengthened by silicon and nickel elements.The presence of spherical graphite also provides self-lubrication and heat conduction and prevents the propagation of cracks.Carbides in the appropriate amount and size strengthen the matrix,reduce the cracking effect of the matrix,and are not easily broken,thereby reducing high-temperature abrasive wear.Under the same hightemperature friction and wear conditions,compared with semi-steel,the wear-scar surface of graphitic steel exhibits less wear-scar depth and wear volume,a smaller friction coefficient,reduced oxide layer thickness,and fewer instances of peeling and microcracks.Therefore,the newly designed graphitic steel has higher wear resistance and hot-crack resistance than semi-steel,which makes it feasible for use in replacing semi-steel as a new V1 frame roll material in the blooming mill.

A novel route to enhance high-temperature mechanical property and thermal shock resistance of low-carbon Mgo-C bricks by introducing ZrSiO_(4)

Conventional MgO-C bricks(graphite content>14 wt.%)produce a great deal of greenhouse gas emission,while low-carbon MgO-C bricks have serious thermal shock resistance during high-temperature service.To enhance the high-temperature mechanical property and thermal shock resistance of low-carbon MgO-C bricks,a novel route of introducing ZrSiO_(4) powder into low-carbon MgO-C bricks was reported in such refractories with 2 wt.% flaky graphite.The results indicate that the low-carbon MgO-C brick with 0.5 wt.%ZrSiO_(4) addition has the maximum hot modulus of rupture at 1400℃ and the corresponding specimen fired in the carbon embedded atmosphere has the maximum residual strength ratio(98.6%)after three thermal shock cycles.It is found that some needle-like AlON and plate-like Al_(2)O_(3)-ZrO_(2) composites were in situ formed in the matrices after the low-carbon MgO-C bricks were coked at 1400℃,which can enhance the high-temperature mechanical property and thermal shock resistance due to the effect of fiber toughening and particle toughening.Moreover,CO_(2) emission of the newly developed low-carbon MgO-C bricks is reduced by 58.3% per ton steel after using them as the working lining of a 90 t vacuum oxygen decarburization ladle.

Graphene Aerogel Composites with Self‑Organized Nanowires‑Packed Honeycomb Structure for Highly Efficient Electromagnetic Wave Absorption

With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.