Research on the solid particle erosion wear of pipe steel for hydraulic fracturing based on experiments and numerical simulations

Erosion wear is a common failure mode in the oil and gas industry.In the hydraulic fracturing,the fracturing pipes are not only in high-pressure working environment,but also suffer from the impact of the high-speed solid particles in the fracturing fluid.Beneath such complex conditions,the vulnerable components of the pipe system are prone to perforation or even burst accidents,which has become one of the most serious risks at the fracturing site.Unfortunately,it is not yet fully understood the erosion mechanism of pipe steel for hydraulic fracturing.Therefore,this article provides a detailed analysis of the erosion behavior of fracturing pipes under complex working conditions based on experiments and numerical simulations.Firstly,we conducted erosion experiments on AISI 4135 steel for fracturing pipes to investigate the erosion characteristics of the material.The effects of impact angle,flow velocity and applied stress on erosion wear were comprehensively considered.Then a particle impact dynamic model of erosion wear was developed based on the experimental parameters,and the evolution process of particle erosion under different impact angles,impact velocities and applied stress was analyzed.By combining the erosion characteristics,the micro-structure of the eroded area,and the micro-mechanics of erosion damage,the erosion mechanism of pipe steel under fracturing conditions was studied in detail for the first time.Under high-pressure operating conditions,it was demonstrated through experiments and numerical simulations that the size of the micro-defects in the eroded area increased as the applied stress increased,resulting in more severe erosion wear of fracturing pipes.

Erosion Wear Behaviour of Kenaf/Glass Hybrid Polymer Composites

The awareness amongst the researchers to develop an environment friendly sustainable material leads to explore new class of plant-based fiber for making composites. Hybridization of such plant-based fiber with inclusion of engineered fiber is one of the promising methods to not only enhanced the mechanical performance but also suppressed the drawbacks that associate with such plant-based fiber to some extent. A usual hand lay-up method was taken-up in this work to fabricate four layered of hybrid kenaf(K)/glass(G)polyester laminates with different stacking order such as KKKK,KGKG,KGGK,GKKG and GGGG. The erosive character of the laminates was examined under three distinct particle velocities(48m/s, 70m/s,82m/s)and four different impact angles(30°, 45°, 60°, 90°). All fabricated laminates exhibited a semiductile character at lower velocities(48m/s and70m/s)as peak wear rate was observed at45° impact angle. However,they showed a semi-brittle character at high velocity(82m/s)as maximum rate of erosion was noticed at60° impact angle. Again,the influence of stacking order of piles on erosion wear was also clearly noticed. Moreover,the semi-brittle/semi-ductile characterization was also evidenced in accordance to the range of erosion efficiencies. The micro-structures of worn surfaces were inspected thoroughly from the images of scanning electron microscope(SEM)to evident the mechanism of erosion.

Erosion wear at the bend of pipe during tailings slurry transportation:Numerical study considering inlet velocity,particle size and bend angle

Pipeline hydraulic transport is a highly efficient and low energy-consumption method for transporting solids and is commonly used for tailing slurry transport in the mining industry.Erosion wear(EW)remains the main cause of failure in tailings slurry pipeline systems,particularly at bends.EW is a complex phenomenon influenced by numerous factors,but research in this area has been limited.This study performs numerical simulations of slurry transport at the bend by combining computational fluid dynamics and fluid particle tracking using a wear model.Based on the validation of the feasibility of the model,this work focuses on the effects of coupled inlet velocity(IV)ranging from 1.5 to 3.0 m·s^(-1),particle size(PS)ranging from 50 to 650μm,and bend angle(BA)ranging from 45°to 90°on EW at the bend in terms of particle kinetic energy and incidence angle.The results show that the maximum EW rate of the slurry at the bend increases exponentially with IV and PS and first increases and then decreases with the increase in BA with the inflection point at 60°within these parameter ranges.Further comprehensive analysis reveals that the sensitivity level of the three factors to the maximum EW rate is PS>IV>BA,and when IV is 3.0 m/s,PS is 650μm,and BA is 60°,the bend EW is the most severe,and the maximum EW rate is 5.68×10^(-6)kg·m^(-2)·s^(-1).In addition,When PS is below or equal to 450μm,the maximum EW position is mainly at the outlet of the bend.When PS is greater than 450μm,the maximum EW position shifts toward the center of the bend with the increase in BA.Therefore,EW at the bend can be reduced in practice by reducing IV as much as possible and using small particles.

A review of biomimetic research for erosion wear resistance

One of the reasons behind failed engineering surfaces and mechanical components is particle erosion wear;thus,to mitigate its happening,biomimetic engineering is the current state-of-the-art being applied.Hence,this paper reviews the literature and the development trends on erosive wear resistance that employ biomimetic methods as well as analyze the bio-inspired surface,the bio-inspired structure,the bio-based materials,the associated challenges,and the future trends.Furthermore,the feasibility of the multi-biological and perspective on the coupling biomimetic method for anti-erosion wear are studied.It is concluded that the design of anti-erosion materials or structures by the bio-inspired methods is of great significance in the development of engineering applications.

The hydro-abrasive erosion wear behavior of duplex-treated surfaces of AISI H13 tool steel

The influence of duplex surface treatments consisting of a DC-pulsed plasma nitriding process and subsequent coatings of CrN and TiAlN deposited by physical vapor deposition(PVD)on AISI H13 tool steel was studied in this article.The treated samples were characterized using metallographic techniques,SEM,EDS,and microhardness methods.Hydro-abrasive erosion wear tests were performed in a specifically designed wear tester in which the samples were rotated in a wear tank containing a mixture of distilled water and ceramic abrasive chips with a fixed rotational speed.The wear rates caused by the abrasive particle impacts were assessed based on accumulated weight loss measurements.The worn surfaces were also characterized using optical microscopy,SEM,and EDS.Microhardness measurements indicated a significant increase in the surface hardness of the duplex-treated samples.The surfaces of the samples with the TiAlN coating were approximately 15 times harder than that of the untreated samples and 3 times that of the plasma nitrided samples.Hydro-abrasive erosion wear results showed that the duplex surface treatments,especially the CrN coating,displayed the highest erosion wear resistance.

Erosive Wear Study of PPLSF/Glass Fiber Reinforced Hybrid Laminates

This work is focused to examine the erosive performance of hybrid Palmyra palm leaf stalk fiber(PPLSF)/glass polyester laminate against solid particle bombardment.A hand lay-up method was adopted for the fabricating four piles of five distinct laminates with different stacking order glass and PPLSF layers.Amongst them,one group of pure PPLSF and pure E-glass laminates were fabricated.The hybrid laminates were exposed to high speed stream of solid sand particle at three distinct impact velocities(48,70 and 82 m/s)and four different angles of impingement(30°,45°,60°and 90°).The effect of particle velocity,angle of impingement and stacking order on both wear rate and efficiency were highlighted.The experimental assessment reveals a significant improvement in erosive wear resistance properties due to hybridization of PPLSF with E-glass.Again,the laminates with PPLSF layer as skin and glass as core layer exhibited better erosive wear resistance properties than other types of laminates.Further,a maximum value of erosion at lower velocity(48 m/s)is also noticed at 45°impingement angle.However,at high velocity of impact 70 m/s and 82 m/s,the maximum rate of erosion has been shifted from 45°impact angle to 60°impact angle.The alternation of this semi-ductile character to semi-brittle character is evidenced by analyzing the experimental data.Further to justify the mode of erosion,the eroded surface samples were inspected by scanning electron microscope(SEM).

Numerical study on erosion behavior of sliding sleeve ball seat for hydraulic fracturing based on experimental data

The sleeve sealing ball seat is one of the important components in the multistage fracturing process of horizontal wells.The erosion and wear of the surface will decrease the sealing performance of the fracturing ball and the ball seat.This leads to pressure leakage during the fracturing process and fracturing failure.In this paper,combined with the actual ball seat materials and working conditions during the fracturing process,the erosion tests of ductile iron and tungsten carbide materials under different erosion speeds,angles,and mortar concentrations are carried out.Then the erosion test results were analyzed by mathematical fitting,and a set of erosion models suitable for sliding sleeve setting ball seat materials were innovatively established.For the first time,this paper combines the erosion model obtained from the experiment and the computational fluid dynamics(CFD)with Fluent software to simulate the erosion of the ball seat.Based on the simulation results,the morphology of the sliding sleeve seat ball after erosion is predicted.Through analysis of the test and simulation results,it is showed that the erosion rate of tungsten carbide material is lower and the wear resistance is better under the condition of small angle erosion.This research can offer a strong basis for fracturing site selection,surface treatment methods,and prediction of failure time of ball seats.

RESEARCH ON EROSION OF SILICON CARBIDE CERAMIC BLADE

In this paper, three linds of silicon carbide ceramic materials are chosen to perform the tests of material erosive wear. The relationship of ambient parameters, abrasive property and target property is studied in these experiments. Some main factors affecting erosive wear rate are determined by analysis of testing results, step wise regression analysis is completed according to the nondimensional quantities obtained by dimensional analysis. Relative hardness (partide to target Hp/Ht and erosion factor (Hpd1/2/Kic) are put for-ward to evaluate erosion property.

Erosive Wear and Wear Mechanism of in situ TiC_P/Fe Composites

The base structure of in situ TiCp/Fe composites fabricated under industrial condition was changed by different heat treatments. Erosive wear tests were carried out and the results were compared with that of wear-resistant white cast iron. The results suggest that the wear resistance of the in situ TiCp/Fe composite is higher than that of wear-resistant white cast iron under the sand erosive wear condition. The wear mechanism of the wear-resistant white cast iron was a cycle process that base surface was worn and carbides were exposed, then carbides was broken and wear pits appeared. While the wear mechanism of in situ TiCp/Fe composite was a cycle process that base surface was worn and TiC grains were exposed and dropped. The wear resistance of in situ TiCp/Fe composite was lower than that of wear-resistant white cast iron under the slurry erosive wear condition. Under such circumstance, the material was not only undergone erosive wear but also electrochemistry erosion due to the contact with water in the medium. The wear behaviours can be a combination of two kinds of wear and the sand erosive wear is worse than slurry erosive wear.

Taguchi approach to influence of processing parameters on erosive wear behaviour of Al7034-T6 composites

Taguchi technique was used to predict the influence of processing parameters on the erosive wear behavior Al7034-T6composite reinforced with SiC and Al2O3particles in different mass fractions.These hybrid metal matrix composites(HMMCs)werefabricated by using a simple technique called stir casting technique.Scanning electron microscope(SEM)was used to study thesurface morphology of the composite and its evolution according to processing time.The design of experiment(DOE)based onTaguchi’s L16orthogonal array was used to identify various erosion trials.The most influencing parameter affecting the wear rate wasidentified.The results indicate that erosion wear rate of this hybrid composite is greatly influenced more by filler content and impactvelocity respectively compared to other factors.This also shows the significant wear resistance with the increase in the filler contentsof SiC and Al2O3particles,respectively.

Analysis on cavitation erosion resistance of isostatic graphite

Isostatic graphite materials with 8%porosity and 14%porosity were prepared by the cold isostatic pressing process.Cavitation erosion resistance of the isostatic graphite was evaluated through cavitation tests in an ultrasonic vibration system.The volume loss and erosion morphology of the isostatic graphite were adopted to investigate the cavitation erosion resistance of the isostatic graphite.The cavitation test results show that after ultrasonic vibration of 14 h,the volume loss of the isostatic graphite materials with 8%porosity and 14%porosity are 35%and 46%of the carbon graphite material,respectively.The isostatic graphite material with 8%porosity exhibits an outstanding capability to resist cavitation erosion damage,and the cavitation erosion resistance of the isostatic graphite enhances with the decrease in porosity.The damage mechanism of isostatic graphite is brittle fracture attributed to the shock wave and micro jet.The isostatic graphite with low porosity exhibits excellent cavitation erosion resistance due to its fine graphite particles,homogeneous structure and high degree of hardness.

Study of the Wear and Corrosion Performance of Hard Coatings Applied by Different Processes on Low Carbon Steel

Most of materials used in applications that require high wear resistance also undergo corrosive action of the service environment. The damage caused by the combination of both processes on the materials leads to huge economic losses in industry. Hard coatings are widely used as engineering solution to increase the lifetime of components operating in conditions of wear combined with corrosion. Nowadays, the most versatile techniques for applying such coatings are welding and thermal spraying. This work evaluates and compares the properties of coatings obtained by thermal spraying and welding using selected feeding materials. The performance of the coatings in corrosion and erosive wear tests is discussed. From the erosion tests performed for impact angle of 90°, a similar performance for the thermally sprayed tungsten carbide coatings and the welded stainless steel coatings with higher input energy was observed. Welded samples presented the best performance in corrosion test.

Assessment of the Erosive Wear Kinetics of Epoxy Coatings Modified with Nanofillers

The paper presents results of investigation on the erosive wear kinetics of epoxy coatings modified with alumina or silica nanoparticles. Natural weathering caused a decrease of their erosive wear resistance. After a 3-year natural weathering, highest erosive wear resistance showed the epoxy coating modified with alumina nanoparticles.

煤炭地下气化节流工具冲蚀磨损研究

煤炭地下气化时,井下高温高压气体携带大直径的煤粉颗粒对节流工具造成严重的冲蚀磨损。为此,设计了双节流孔结构的井下节流工具,并结合高温冲蚀磨损试验结果对DNV(Det Norske Vertitas)冲蚀预测模型进行参数修正。开展了井下节流工具气固两相流冲蚀磨损数值模拟,研究高温条件下不同气体速度、不同颗粒质量流量及不同颗粒直径对节流工具的冲蚀磨损规律。研究结果表明:节流工具壁面冲蚀磨损区域随着气体流速的增大沿节流孔呈现环形分布;颗粒直径为5 mm,质量流量为7.5×10^(-4) kg/s,气体速度为20 m/s时,其对应的节流工具壁面冲蚀磨损速率最大。所得结论可为延长节流工具的安全服役年限、降低管线破损及爆炸的风险以及提高煤炭地下气化开采的经济性提供指导。

Influence and optimization of swirler parameters on elbow wear of deep coal fluidization pipeline transportation system

Elbow wear is a major threat to the multiphase pipeline transportation industry,which has a negative impact on the stable operation of the transportation system.In order to find the wear reduction methods of elbows in the fluidization pipeline transportation system for 2000-meter-deep coal resources,the swirler was installed upstream of the elbows,and wear simulations and tests of three kinds of elbows were carried out.The results showed that the maximum wear rate(MWR)of elbows increased and then decreased along the elbow angle.Due to the different directions of gravity,the heavy wear position(HWP)of the horizontal-vertical(H-V)elbow was in front of the vertical-horizontal(V-H)elbow.Because the downstream portion of the horizontal-horizontal(H-H)elbow was still a horizontal pipe,the HWP of the H-H elbow almost covered the whole elbow.The swirler placed upstream of the elbows could make the particles at the elbow move to the intrados of the elbows,resulting in less collision between the particles and the extrados of the elbows,thus reducing the wear of the elbows.The wear reduction effects of swirlers on three different elbows were favorably connected with the guide vane angle(GVA)and negatively correlated with the guide vane length(GVL),decreased first and then increased as the guide vane height(GVH)increased,and were little affected by the guide vane number(GVN)and the guide vane thickness(GVT).The mathematical models between the MWR of the elbows and guide vane parameters were established.By bench tests,the wear reduction effect of three kinds of elbows under the optimal guide vane parameters was 58.4%,76.9%,and 78.6%,respectively.The errors between the bench test results and the simulation results were around 10%.

Effect of laser shock processing on erosive resistance of 6061-T6 aluminum

Application of laser shock processing （LSP） on 6061-T6 aluminum was made in order to evaluate its response to the erosive wear by silica sand. Impact angles of 15° , 30° , 60° and 90° were tested, two particle speeds （37 and 58 m/s） and two LSP irradiation conditions were used. Erosion marks were characterized by 3D profilometry and SEM analysis was conducted to identify the erosion mechanisms for each tested angle. The results showed a maximum erosive wear at low impact angles （ductile type behavior）. Erosion strength and the erosion mechanisms were not affected by the application of LSP and they were attributed to the high strain rate of the erosion phenomena. A few differences encountered on the erosion plots were explained on the basis of the surface roughness left by the LSP process. The maximum mass loss and the maximum erosion penetration happened in different impact angles （15° and 30° , respectively）. Finally, a well-defined erosion mechanism transition was observed, from cutting action at low impact angle, to crater formation at 90° of incidence.

Effects of Nano-Aluminium on The Combustion of A PolyNIMMO-Based Propellant

Propellants containing micro-aluminium particles have been shown to produce faster burn rates than conventional gun propellants.However,they are also more abrasive than conventional propellants.Nano-material propellants have been reported to give similar benefits to micron-material propellants but without the disadvantage of increased abrasion.Tests were conducted to compare the burn rates,ignitability and wear rates of a propellant loaded with 0% aluminium,15% micro-aluminium and 15%nano-aluminium.Closed vessel tests showed a burn rate increase of 39% in the range 30-250 MPa,and 70% at low pressure(50-100MPa)for the nano-aluminium propellant compared with the baseline propellant.The micro-aluminium propellant showed only a 10%increase in the burn rate compared with the standard propellant.The ignition delay for the nano-aluminium propellant was slightly shorter than that of the baseline propellant.Substantially increased wear rates were measured for the micro-aluminium propellant.The nano-aluminium propellant showed reduced wear rates compared with the micro-aluminium propellant but these were still substantially greater than those for the baseline propellant.

鼓丘和巨型冰川线理的冰川摩擦学:剥蚀和沉积的争论之谜得到解决?

冰流是指冰盖中快速流动(高达10 km/a)的区域。冰流通常长达1000 km,宽200 km,嵌入在冰盖中。沿其流动方向形成了低幅度波纹状基岩床。这些波纹状基岩床由一些高度拉伸的沿着流向呈平行状分布的脊和沟槽(巨型冰川线理)组成。这些巨型冰川线理在空间上继承自体积大、拉伸程度低的鼓丘。由于鼓丘核部的地质条件复杂多变且不存在特征性的岩相,同时很难直接观察到现代冰盖下鼓丘的形成,因而鼓丘的起源在世界上仍然是未解之谜。基于新的高分辨率(0.5 m)LiDAR数据绘制的地形图和对更新世古冰流岩床进行野外地质考察表明,鼓丘和巨型冰川线理是底形连续体(后者由前者演化而来)。它们由基岩或部分岩石和早期较老的沉积物组成,基于此部分学者提出了鼓丘的侵蚀起源说。本文重点介绍了类似鼓丘和巨型冰川线理的椭圆-流线型和带有沟槽的表面,这些表面广泛形成于多种非冰川的地质环境中(无论是在地球上还是在火星上),它们是由于受限剪切作用下颗粒状碎屑对基底面的磨损所产生的。变质核杂岩中的大型滑脱断层和俯冲带巨型逆冲断层的表面显示出槽状表面,其形状和规模能够与巨型冰川线理相类比。多尺度的断层面上都表现出了逐渐消除的类似鼓丘状的"椭圆形凸起",形成带凹槽的岩石光滑面,从而减少了阻力并允许继续滑动。现代冰流岩床记录的冰下地震的独特"纹理"与凹槽内基底面遭受的局部侵蚀和剪切一致,冰下地貌特征加强了与断层运动学的联系。火山碎屑流、陨石撞击坑周围的溅射毯以及滑坡和块体搬运沉积体系的滑动,它们的下垫面都会形成类似巨型冰川线理的沟槽。在人造和生物材料的摩擦接触表面上,也可以重现这些由粒状"磨损碎屑"(被定义为"第三层")切割形成的类似鼓丘的椭圆形凸起和类似巨型冰川线理的沟槽表面。因此,我们提议将鼓丘和巨型冰川线理作为冰川动力学研究的相关组成部分,可以称之为"磨损痕迹"或者"流向剪切痕"。它们是由于不同的冰流速度拖曳粗颗粒的变形冰碛物切割底面(沉积物或者岩石(或其他岩相组合))形成的。地学界颇具争议的鼓丘-冰川线理成因谜团已逐渐清晰。

An erosion model for the discrete element method

A shear impact energy model （SIEM） of erosion suitable for both dilute and dense particle flows is pro- posed based on the shear impact energy of particles in discrete element method （DEM） simulations. A number of DEM simulations are performed to determine the relationship between the shear impact energy predicted by the DEM model and the theoretical erosion energy. Simulation results show that nearly one-quarter of the shear impact energy will be converted to erosion during an impingement. According to the ratio of the shear impact energy to the erosion energy, it is feasible to predict erosion from the shear impact energy, which can be accumulated at each time step for each impingement during the DEM simulation. The total erosion of the target surface can be obtained by summing the volume of material removed from each impingement. The proposed erosion model is validated against experiment and results show that the SIEM combined with DEM accurately predicts abrasive erosions.

STUDIES OF SOLID－LIQUID TWO－PHASE TURBULENT FLOWS AND WEAR IN HYDRAULIC TURBOMACHINERY

The Lagrangian equation of motion for solid particles in an arbitrary flow field is derived. The linear differential equation form and the general solution of this equation are obtained. Motion of solid particles in dilute solid-liquid turbulent flows is numerically solved and analysed. The K-εtwo-equation turbulence model, the volume fraction turbulence model, the mixed Eulerian-Lagrangian turbulence model, and the dense mixture turbulence model as well as the erosive wear model are developed. Using these models, the turbulent flows and the erosive wear in some hydraulic turbomachinery ducts are numerically predicted. The numerical results show good agreement with the experiments.