Influences of shale microstructure on mechanical properties and bedding fractures distribution

The difference in microstructure leads to the diversity of shale mechanical properties and bedding fractures distribution patterns.In this paper,the microstructure and mechanical properties of Longmaxi marine shale and Qingshankou continental shale were studied by X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)with mineral analysis system,and nanoindentation.Additionally,the typical bedding layers area was properly stratified using Focused Ion Beam(FIB),and the effects of microstructure and mechanical properties on the distribution patterns of bedding fractures were analyzed.The results show that the Longmaxi marine shale sample contains more clay mineral grains,while the Qingshankou continental shale sample contains more hard brittle mineral grains such as feldspar.For Longmaxi marine shale sample,hard brittle minerals with grain sizes larger than 20μm is18.24%and those with grain sizes smaller than 20μm is 16.22%.For Qingshankou continental shale sample,hard brittle minerals with grain sizes larger than 20μm is 40.7%and those with grain sizes smaller than 20μm is 11.82%.In comparison to the Qingshankou continental shale sample,the Longmaxi marine shale sample has a lower modulus,hardness,and heterogeneity.Laminated shales are formed by alternating coarse-grained and fine-grained layers during deposition.The average single-layer thickness of Longmaxi marine shale sample is greater than Qingshankou continental shale sample.The two types of shale have similar bedding fractures distribution patterns and fractures tend to occur in the transition zone from coarse-grained to fine-grained deposition.The orientation of the fracture is usually parallel to the bedding plane and detour occurs in the presence of hard brittle grains.The fracture distribution density of the Longmaxi marine shale sample is lower than that of the Qingshankou continental shale sample due to the strong heterogeneity of the Qingshankou continental shale.The current research provides guidelines for the effective development of shale reservoirs in various sedimentary environments.

The influences of perforating phase and bedding planes on the fracture deflection in laminated shale

The perforating phase leads to complex and diverse hydraulic fracture propagation behaviors in laminated shale formations. In this paper, a 2D high-speed imaging scheme which can capture the interaction between perforating phase and natural shale bedding planes was proposed. The phase field method was used to simulate the same conditions as in the experiment for verification and hydraulic fracture propagation mechanism under the competition of perforating phase and bedding planes was discussed.The results indicate that the bedding planes appear to be no influence on fracture propagation while the perforating phase is perpendicular to the bedding planes, and the fracture propagates along the perforating phase without deflection. When the perforating phase algins with the bedding planes, the fracture initiation pressure reserves the lowest value, and no deflection occurs during fracture propagation. When the perforating phase is the angle 45°, 60°and 75°of bedding planes, the bedding planes begin to play a key role on the fracture deflection. The maximum deflection degree is reached at the perforating phase of75°. Numerical simulation provides evidence that the existence of shale bedding planes is not exactly equivalent to anisotropy for fracture propagation and the difference of mechanical properties between different shale layers is the fundamental reason for fracture deflection. The findings help to understand the intrinsic characteristics of shale and provide a theoretical basis for the optimization design of field perforation parameters.

Fracture geometry and breakdown pressure of radial borehole fracturing in multiple layers

Radial borehole fracturing that combines radial boreholes with hydraulic fracturing is anticipated to improve the output of tight oil and gas reservoirs.This paper aims to investigate fracture propagation and pressure characteristics of radial borehole fracturing in multiple layers.A series of laboratory experiments with artificial rock samples(395 mm×395 mm×395 mm)was conducted using a true triaxial fracturing device.Three crucial factors corresponding to the vertical distance of adjacent radial borehole layers(vertical distance),the azimuth and diameter of the radial borehole are examined.Experimental results show that radial borehole fracturing in multiple layers generates diverse fracture geometries.Four types of fractures are identified based on the connectivity between hydraulic fractures and radial boreholes.The vertical distance significantly influences fracture propagation perpendicular to the radial borehole axis.An increase in the vertical distance impedes fracture connection across multiple radial borehole layers and reduces the fracture propagation distance along the radial borehole axis.The azimuth also influences fracture propagation along the radial borehole axis.Increasing the azimuth reduces the guiding ability of radial boreholes,which makes the fracture quickly curve to the maximum horizontal stress direction.The breakdown pressure correlates with diverse fracture geometries observed.When the fractures connect multi-layer radial boreholes,increasing the vertical distance decreases the breakdown pressure.Decreasing the azimuth and increasing the diameter also decrease the breakdown pressure.The extrusion force exists between the adjacent fractures generated in radial boreholes in multiple rows,which plays a crucial role in enhancing the guiding ability of radial boreholes and results in higher breakdown pressure.The research provides valuable theoretical insights for the field application of radial borehole fracturing technology in tight oil and gas reservoirs.

中国式现代化视域下共同富裕的科学内涵、价值意蕴与实现路径

共同富裕既是中国式现代化的重要特征,也是社会主义的本质要求。回顾中国共产党百年来的奋斗历程,我们可以清楚地看到党为实现共同富裕所付出的艰辛努力和取得的非凡成就。从科学内涵上看,共同富裕是不断完成国家独立、制度变革、体制完善、全面发展的中国式现代化的历史过程。从价值意蕴上看,共同富裕既是推动实现全体人民物质生活和精神生活的双重富裕,也是实现人与自然和谐共生的共同富裕。从实现路径上看,实现共同富裕始终坚持党的全面领导、推动高质量发展、秉持以人民为中心发展理念、不断健全社会制度体系。

糖尿病肾病肾功能不全的影响因素及肿瘤坏死因子-α对其预测价值

目的:分析糖尿病肾病(DN)肾功能不全影响因素及肿瘤坏死因子-α(TNF-α)对DN肾功能不全预测价值。方法:回顾性分析2022年1-5月大同市第五人民医院住院治疗的DN患者90例,根据肾小球滤过率(e-GFR)是否<60 mL/(min·1.73 m^(2)),将所有DN患者分为肾功能不全组(41例)和非肾功能不全组(49例),比较两组临床资料,将差异有统计学意义的指标纳入二元logistic回归分析,并分析TNF-α对肾功能不全预测价值。结果:肾功能不全组病程、TNF-α、中性粒细胞/淋巴细胞(NLR)、C反应蛋白(CRP)均明显高于非肾功能不全组,e-GFR、白蛋白(ALB)均明显低于非肾功能不全患者(P<0.05)。二元logistic回归分析显示,病程、TNF-α、NLR均为DN患者肾功能不全独立影响因素,ALB为保护性因素(OR=1.398、1.066、16.945、0.765,P<0.05)。NLR与CRP,HbA1c与FPG呈正相关,BUN与ALB呈负相关(r=0.322、0.201、-0.279),差异有统计学意义(P<0.05)。TNF-α预测DN肾功能不全AUC为0.714(95%CI:0.609,0.819),最佳截断值为102.50 pg/mL,预测敏感度为65.85%,特异度为73.47%。结论:病程、TNF-α、NLR、ALB为DN肾功能不全独立影响因素,且TNF-α对其有一定预测价值。

马克思世界历史理论视域下中国式现代化道路的三重逻辑

中国式现代化道路与马克思世界历史理论一脉相承、逻辑贯通、实践关联。从理论逻辑看,中国式现代化道路遵循世界历史运行逻辑和规律,源于对世界历史发展进程的深刻认识和人类社会历史发展趋势的科学把握。从实践逻辑看,中国式现代化道路充分体现了中国共产党在融入世界历史进程中,展现出高度的世界历史自觉和强烈的历史主动精神。从价值逻辑看,中国式现代化道路是具有世界历史意义的中国智慧,不仅拓展了人类走向现代化的路径选择,而且积极地开创了人类文明新形态,为世界社会主义发展注入全新活力。

门诊电子病历系统的开发与应用

本文结合门诊电子病历系统的国内外应用现状及在无锡市第二人民医院上线应用情况,介绍了门诊电子病历的产品特点与应用优势,通过完善病历模板和输入智能知识库来提高使用率、门诊病历质量和医疗服务效率,用信息化技术手段实现医疗信息互联互通。最后为医院门诊电子病历系统的建设与应用提供了指导与建议。

中国共产党把握社会主要矛盾本质的四重逻辑

在马克思主义发展史上,中国共产党重大理论与实践贡献之一就是社会主要矛盾论断的创新与发展。鉴于其具有持续的重大现实指导意义、科学的方法论遵循、自洽的科学结构、丰富的实践验证,因而完全可以成为马克思主义中国化创新成果中基本的科学范畴。这就需要对其本质作出全面揭示。从历史逻辑上讲,社会主要矛盾判断是对马克思主义矛盾发展理论的丰富与发展;从理论逻辑上讲,社会主要矛盾判断是以推动发展进步为核心有其科学内涵、科学方法、科学结构的科学体系;在现实逻辑上,解决社会主要矛盾是不断认识和改变基本国情的发展实然同发展应然之间的矛盾演进。在实践逻辑上,认识解决社会主要矛盾构成为中国革命、建设和改革发展的基本经验。

论中国特色网络意识形态话语体系建构的基本逻辑

中国特色网络意识形态话语体系建构具有独特的建构逻辑,体现在政治立场、理论体系、思维方法、话语表达、话语传播、价值体系建构有机统一的基本逻辑之中。政治立场建构是前提和基础,集中体现在话语内容和话语标识的鲜明立场建构之中;理论体系建构要以中国特色社会主义理论体系科学的话语范畴和话语基础为依据,呈现科学性和统合力;话语表达建构要以准确性、生动性、主导性、规范性为必要条件;传播体系建构要充分体现话语传播的融合性、有效性、多样性、可感性,不断增强主流意识形态的影响力、表现力;价值体系构建要彰显话语核心和话语发展的价值性、导向性、开放性和创新性,凸显社会主义核心价值观的引领力和发展力,牢牢掌握中国特色社会主义意识形态的领导权和话语权。

中国共产党建党百年解决社会主要矛盾的逻辑意蕴

中国共产党领导中国人民准确把握、正确处理不同历史时期社会主要矛盾,保证党和国家的事业取得了一次次伟大胜利,形成了一系列独具中国特色的理论与实践原创性成果。文章深入剖析了中国共产党建党百年解决社会主要矛盾历史逻辑、理论逻辑和实践逻辑,揭示其理论和实践原创性所在,阐释了正确解决社会主要矛盾的创新"密码"和现实意蕴。

Pore structure characterization and its effect on methane adsorption in shale kerogen

Pore structure characterization and its effect on methane adsorption on shale kerogen are crucial to understanding the fundamental mechanisms of gas storage,transport,and reserves evaluation.In this study,we use 3D scanning confocal microscopy,scanning electron microscopy(SEM),X-ray nano-computed tomography(nano-CT),and low-pressure N2 adsorption analysis to analyze the pore structures of the shale.Additionally,the adsorption behavior of methane on shales with different pore structures is investigated by molecular simulations.The results show that the SEM image of the shale sample obviously displays four different pore shapes,including slit pore,square pore,triangle pore,and circle pore.The average coordination number is 4.21 and the distribution of coordination numbers demonstrates that pores in the shale have high connectivity.Compared with the adsorption capacity of methane on triangle pores,the adsorption capacity on slit pore,square pore,and circle pore are reduced by 9.86%,8.55%,and 6.12%,respectively.With increasing pressure,these acute wedges fill in a manner different from the right or obtuse angles in the other pores.This study offers a quantitative understanding of the effect of pore structure on methane adsorption in the shale and provides better insight into the evaluation of gas storage in geologic shale reservoirs.

论社会主要矛盾转化对于创造中国式现代化道路的时代价值

中国式现代化道路的成功开创,从根本上取决于中国式现代化的时代价值。中国式现代化道路最令人称道的地方在于改写了近代以来资本主义强国的现代化逻辑,由此,中国式现代化具有较强的世界意义和时代价值。社会主要矛盾转化凸显了中国式现代化全面超越于西方式的现代化,中国式现代化道路又不断创造了人类文明新形态。中国式现代化道路的成功体现为,社会主要矛盾转化作为动力之源,从发展活力上创造了巨大人口规模的现代化,从发展初心上创造了全体人民共同富裕的现代化,从科学发展上创造了物质文明和精神文明相协调的现代化,从文明跃升上创造了人与自然和谐共生的现代化,从人类共同进步上创造了走和平发展道路的现代化。

婴儿胸壁错构瘤5例临床病理学分析

目的分析婴儿胸壁错构瘤的临床病理学特征、影像学特征、以及诊断与鉴别诊断,旨在提高临床医生对该罕见疾病的认识。方法对5例发生于婴儿的胸壁错构瘤的临床特征、病理组织学特点及免疫表型进行分析,并复习相关文献。结果5例患者均表现为逐渐增大的胸壁肿块,常伴呼吸道症状,男女比例为3∶2,左侧与右侧比例为3∶2,3例患儿累及一根肋骨,2例患儿病灶累及多根肋骨,中位年龄7个月。CT表现为来源于肋骨的肿块呈膨胀、筛网状结构,肿块内密度不均,呈不规则钙化密度影及软组织团块影。病理学大体上表现为囊性与实性相间的肿块,囊性区可有黏液、出血。镜下瘤组织实性区由透明软骨组织、胶原纤维组织增生为主,可见软骨内成骨;出血性囊性区见动脉瘤样骨囊肿样结构。所有标本中以上成份均以不同比例呈现,免疫组化可提示病变各组织成分来源。5例患者均行手术完整切除治疗。结论婴儿胸壁错构瘤是一种临床非常罕见的良性疾病,术前常被误诊为恶性肿瘤,具有特殊的临床病理学特征,治疗以手术完整切除为主。

Productivity enhancement in multilayered coalbed methane reservoirs by radial borehole fracturing

Coalbed methane(CBM)is an important unconventional natural gas.Exploitation of multilayered CBM reservoir is still facing the challenge of low production rate.Radial borehole fracturing,which integrates radial jet drilling and hydraulic fracturing,is expected to create complex fracture networks in multilayers and enhance CBM recovery.The main purpose of this paper is to investigate the mechanisms and efficacy of radial borehole fracturing in increasing CBM production in multiple layers.First,a two-phase flow and multi-scale 3 D fracture network including radial laterals,hydraulic fractures and face/butt cleats model is established,and embedded discrete fracture model(EDFM)is applied to handle the complex fracture networks.Then,effects of natural-fracture nonuniform distribution are investigated to show the advantages of targeted stimulation for radial borehole fracturing.Finally,two field CBM wells located in eastern Yunnan-western Guizhou,China were presented to illuminate the stimulation efficiency by radial borehole fracturing.The results indicated that compared with vertical well fracturing,radial borehole fracturing can achieve higher gas/water daily production rate and cumulative gas/water production,approximately 2 times higher.Targeted communications to cleats and sweet spots and flexibility in designing radial borehole parameters in different layers so as to increase fracture-network complexity and connectivity are the major reasons for production enhancement of radial borehole fracturing.Furthermore,the integration of geology-engineering is vital for the decision of radial borehole fracturing designing scheme.The key findings of this paper could provide useful insights towards understanding the capability of radial borehole fracturing in developing CBM and coal-measure gas in multiple-thin layers.

CFD analysis and field observation of tool erosion caused by abrasive waterjet fracturing

Abrasive waterjet(AWJ)fracturing has become an accepted horizontal multistage stimulation technique due to its flexibility and high efficiency of extensive fracture placement.The downhole tool failure of AWJ fracturing becomes an issue in the massive hydraulic fracturing because of high velocity and proppant erosion.This paper proposed a 3D computational fluid dynamics(CFD)-based erosion model by considering high-velocity waterjet impact,proppant shear erosion,and specific inner structure of hydra-jet tool body.The discrete phase approach was used to track the proppant transport and its concentration distribution.Field observation provides strong evidence of erosion patterns and mechanisms obtained from CFD simulation.The results show that the erosion rate has a space dependence in the inner wall of the tool body.The severe erosion areas are primarily located at the entries of the nozzle.Evident erosion patterns are found including a‘Rabbit’s ear’erosion at the upper-layer nozzles and a half bottom loop erosion at the lower-layer nozzles.Erosion mechanisms attribute to high flow velocity at the entry of nozzles and the inertia force of proppant.Sensitivity analysis demonstrates that the pumping rate is a primary factor contributing to erosion intensity.

Effect of dilute acid treatment on adhesion properties of Longmaxi black shale

Properties of shale in an acid environment are important when acid or CO2 is injected into geologic formations as a working fluid for enhanced oil and gas recovery,hydraulic fracturing and reduced fracture initiation pressure.It has previously been shown that acid fluids can enhance the formation conductivity and decrease the hardness of shale.However,less is known about the effect of dilute acid on the adhesion properties of shale.In the study,shale samples are characterized in detail with advanced analysis.Adhesion properties of shale via dilute acid treatment were revealed by atomic force microscopy(AFM)for the first time.Results indicate that acid treatment can greatly enhance adhesion forces of the shale surface.After acid treatment,the average adhesion forces show a platform-like growth with an increase in loading force.Through analysis of results from AFM,scanning electron microscopy,and X-ray diffraction,we affirm that the enhanced adhesion forces are mainly from increased specific surface area and reduced elastic modulus.The results presented in this work help understand the adhesion properties of shale oil/gas present in an acidic environment,which have great significance in unconventional resources development.

“中国方案”核心要义在于引领和倡导全球价值观

习近平在党的十九大报告中,历史性地提出,中国特色社会主义进入新时代意味着中国特色社会主义道路、理论、制度、文化不断发展,为解决人类问题贡献了中国方案。习近平总书记关于“中国方案”的提法不能与“更好的社会制度”“全球治理方案”“打造人类命运共同体”直接划等号,而是着力于解决这些“制度”“方案”“共同体”所需要的全球价值共识问题,着眼于倡导和引领人类共同需要的全球价值观。习近平总书记广受关注的人类命运共同体倡议,是以既亲切,又深受认同的话语,高度凝练地表达中国特色社会主义新时代所希冀的全球价值共识和全球价值观。

化工园区液氨卧式储罐泄漏扩散特性研究

以某化工园区液氨卧式储罐为对象,采用Phast软件建立了液氨卧式储罐泄漏模型,研究了储罐压力、泄漏孔径、风速、环境温度等因素对液氨泄漏扩散特性的影响。结果表明:随着风速的增大,氨气云团扩散面积变小,影响范围相应变小。随着泄漏孔径的增大,氨气泄漏影响更高的区域。泄漏孔径大于0.09 m时,泄漏孔径不再是影响扩散的主要因素。随着储罐压力的增大,氨气侧视扩散范围逐渐升高,俯视扩散范围逐渐缩小。温度越高,氨气的扩散范围越大。

Influence of formation in-situ stress on mechanical heterogeneity of shale through grid nanoindentation

Mechanical heterogeneity is a major characteristic of the organic-rich shale.The relation between mechanical heterogeneity and formation in-situ stress has been seldomly addressed but important to understand hydraulic fracture propagation,wellbore stability,and hydrocarbon flow.In this paper,the grid nanoindentation technique was used to characterize the heterogeneity of the mechanical properties of Longmaxi organic-rich shales from various burial depths and in-situ stress.The measured elastic modulus and hardness of each sample are deconvolved into three phases including soft phase,medium stiff phase and stiff phase according to mineral category.As the burial depth and corresponding in-situ stress increase,the overall elastic modulus and hardness of the sample enhance.Simultaneously,the percentage of soft minerals decreases,and the probability distribution tends to concentrate through 95%confidence interval evaluation which demonstrates weakened heterogeneity.Furthermore,SEM images provide evidence that extended cracking,initiated cracking,crushing and ductile deforming always occur around indentation imprints.This confirms that even under deep buried depth and high in-situ stress,brittle fracture and ductile deformation can exist synchronously.This paper demonstrates the influence of in-situ stress on the heterogeneity of shale micromechanics.

Hydrophobic epoxy resin coated proppants with ultra-high self-suspension ability and enhanced liquid conductivity

Proppant is a key material for enhancing unconventional oil and gas production which requires a long distance of migration and efficient liquid conductivity paths within the hydraulic fracture.However,it is difficult to find a proppant with both high self-suspension ability and liquid conductivity.Here,a simple method is developed to coat epoxy resin onto the ceramic proppant and fabricate a novel coated proppant with high hydrophobicity,self-suspension,and liquid conductivity performance.Compared with uncoated ceramic proppants,the epoxy resin coated(ERC) proppant has a high self-suspension ability nearly 16 times that of the uncoated proppants.Besides,the hydrophobic property and the liquid conductivity of the ERC proppant increased by 83.8% and 16.71%,respectively,compared with the uncoated proppants.In summary,this novel ERC proppant provides new insights into the design of functional proppants,which are expected to be applied to oil and gas production.