高倍数水驱砂岩中原油黏度、岩心润湿性时变规律核磁共振实验

根据模拟原油黏度与横向弛豫时间谱几何平均值的变化关系,建立了模拟原油黏度预测模型,并结合高倍数水驱核磁共振(NMR)实验实现了孔隙介质中模拟原油黏度的时变规律定量表征;基于核磁共振弛豫理论推导出新的NMR润湿性指数计算公式,结合砂岩岩心高倍数水驱实验,定量表征了水驱过程岩石润湿性的时变规律。研究表明:岩心中剩余油黏度与过水倍数正相关,过水倍数较低时剩余油黏度升高速度较快,过水倍数较高时剩余油黏度升高速度趋缓。剩余油黏度的变化与储层非均质性相关,储层均质性越强,剩余油中重质组分含量越高,黏度越高。注水后储层润湿性将发生改变,亲油储层向亲水储层转变,亲水储层则亲水性更强,且改变程度随过水倍数增加而增强。原油黏度的时变性与润湿性的时变性具有很高的关联性,原油的黏度变化不可忽略,考虑模拟原油黏度变化时计算得到NMR润湿性指数与测试Amott(自吸法)润湿性指数更具有一致性,更加符合储层润湿性时变规律。

气井化学控水研究进展与挑战及对策探析

目前,中国已开发气田80%以上产水,严重影响气井产能。化学控水是提高产水气藏采收率的重要手段。综述了国内外常用气井化学控水材料,讨论了控水机理及适应性。结果表明,聚合物及聚合物凝胶通过阻力效应、惯性效应、润滑效应等实现不成比例气水渗透率降低(Disproportionate Permeability Reduction,DPR),其中,聚合物类堵剂适用于中高孔渗储层,通过“预处理液+改性聚合物”提高其环境适应性;聚合物凝胶适用于高温高矿化度、裂缝性产水气藏;相渗调节剂通过润湿性改变实现DPR,适用于低渗、致密、高产水气藏,不适用于裂缝性气藏;功能流体(纳米流体、微乳液体系等)多针对特定储层(如凝析气藏)条件设计,通过润湿性改变实现DPR;泡沫凝胶通过贾敏效应、分流作用实现DPR,适用于强非均质性和裂缝性气藏。同时,分析了气井控水面临的挑战,并进一步提出了根据水来源制定不同控水策略、研制分离膜控水新材料、预处理液改造储层环境和适度产水与控水一体化等6个气井控水策略及研究方向。研究成果可为气井控水实践提供指导。

碳酸盐岩储层高酸溶多级架桥暂堵型钻井完井液体系

以顺北二区碳酸盐岩储层为研究对象,通过岩心裂缝稳定性校正评价了储层敏感性,开展了现用钻井液伤害评价,明确了储层损害主控因素为应力敏感伤害和固相伤害,2种伤害因素累计占比达78.07%。采取“钻井可暂堵、完井可解堵”理念和保护微裂缝为主的储层保护思路,根据裂缝架桥封堵理论,研选了高酸溶固相封堵材料耦合可降解纤维关键材料。通过抗温、抗盐抗钙、沉降稳定性、配伍性及储层保护性能评价,形成了耐高温180℃多级架桥储层保护钻井完井液体系,其承压超过10 MPa,酸化后渗透率恢复率均值可达96.86%,相对常规不含酸溶暂堵材料体系提高了16.23%,具有强封堵、高返排的特点,有望减轻顺北二区碳酸盐岩储层的损害。

基于MLP-AE网络的电磁层析成像算法

电磁层析成像(electromagnetic tomography, EMT)传统算法由于物理模型的限制,导致重建数据缺失,使其逆问题存在着严重的不适定性和病态性。为解决重建图像普遍存在伪影多,质量差等问题,提出了一种基于MLP-AE的复合电磁层析成像算法。首先用待测物场信息作为输入送入自编码神经网络(AE)学习,得到编码数据;再对待测物场进行电磁激励获取电压数据;将电压数据作为输入,待测物场信息编码后的数据作为输出送入多层感知机神经网络(MLP)学习;最终解码实现端到端的图像重建。通过均方误差、结构相似性指数和成像时间评估所述算法的性能,并与线性反投影算法、Tikhonov正则化算法、Landweber迭代算法进行对比。实验结果表明,所述算法在单幅图像上:均方误差较以上传统算法分别降低了28.77%、22.57%、23.74%,结构相似性指数分别提升了17.54%、14.38%、15.44%,成像时间分别快了73.78%、98.63%、93.86%。所述重建算法对于待测物位置和形状的预测更为精确,时间大幅度减少,为之后进行实时精确成像提供了思路。

基于局部归一化互信息联合约束的三维头颈部CT/MR配准方法

针对头颈部图像的复杂解剖结构和不同模态图像的差异,提出一种改进的多模态配准方法。该方法采用局部归一化互信息作为相似性测度,以捕捉局部图像区域的相似性,并减少不同区域间的强度差异对配准结果的影响。此外,为解决MR图像易受到噪声和伪影的影响产生畸变的问题,引入F范数约束配准过程,抑制不必要的畸变。实验结果表明,所提方法在降低均方误差、提高配准精度和鲁棒性方面均有所提高。

硬岩引水隧洞掘进爆破参数研究

为探究不同岩性时引水隧洞爆破合理的延迟时间和最小抵抗线,以瓯江引水工程三标段隧洞爆破工程为背景,依据理论公式分析了隧洞爆破的合理延时;通过ANSYS数值模拟软件建立不同最小抵抗线的计算模型,对不同工况下岩体内有效应力、裂纹扩展情况进行对比分析。结果表明,对于花岗岩和凝灰岩,随着最小抵抗线增大,对应的延时也增大,有效应力作用呈衰减态势,裂纹扩展逐渐分散;根据优化结果以3m的炮孔深度为例,花岗岩和凝灰岩下掏槽孔与辅助孔、崩落孔间、崩落孔与周边孔的延时分别取80ms,50ms,30ms和90ms,50ms,40ms,最小抵抗线为600mm~650mm,经现场试验表明爆落岩石块度均匀、易于装运,断面轮廓成型规整,炮孔利用率达到91%,光爆效果良好、与研究结果吻合。

基于多维度动态衰减Transformer的轮胎检测算法应用

针对当前国内子午线轮胎缺陷分割困难、成本昂贵的问题,本文提出了如下解决方案,提出一种基于Swin Transformer和注意力特征金字塔的子午线轮胎缺陷分割算法Swin DAA,其中主要使用Swin Transformer作为主干特征提取网络,经过动态衰减注意力特征金字塔增强语义表达能力,搭建由Python语言编写的软件平台,同时级联X射线载重轮胎检测系统采集图像,并且使用TCP协议与上位机通信、传输图像数据,最终将缺陷分割软件系统与MES工控系统连接,完成无人监守的自动化子午线轮胎缺陷分割。实验对比数据显示,本文中提出的Swin DAA网络的精准度达到了82.87%,召回率达到了85.22%,每秒传输帧数达到了11,所集成的软件能良好的完成子午线轮胎的实际监测要求。

明清古籍及诗画中的茶花及其园林应用分析

茶花作为中国的十大传统名花和世界著名花卉,在中国有着近两千年的栽培和应用历史,其在中国的古籍、诗词与绘画中留下了诸多的科学和艺术记忆。在前人对唐宋诗画中茶花及其园林应用初探的基础上,进一步梳理明清时期古籍及诗画中茶花的发展脉络,为更好地探索茶花未来的创新性应用及发展方向提供借鉴。从搜集检索到的明清时期描写茶花的古籍、275诗首词曲赋以及部分绘画作品来看,明清时期的茶花品种多达百余种,在很大程度上丰富了园林应用的植物素材;在园林具体应用方面,茶花在私家园林及寺庙园林中应用频次更高、形式更为丰富,并出现了茶花专类园的雏形;在配植植物方面,茶花与梅花、水仙、竹子的配植依然盛行,并逐渐发展出茶花与玉兰、牡丹、柏树等植物的配置模式。

Opinion consensus incorporating higher-order interactions in individual-collective networks

In the current information society, the dissemination mechanisms and evolution laws of individual or collective opinions and their behaviors are the research hot topics in the field of opinion dynamics. First, in this paper, a two-layer network consisting of an individual-opinion layer and a collective-opinion layer is constructed, and a dissemination model of opinions incorporating higher-order interactions(i.e. OIHOI dissemination model) is proposed. Furthermore, the dynamic equations of opinion dissemination for both individuals and groups are presented. Using Lyapunov's first method,two equilibrium points, including the negative consensus point and positive consensus point, and the dynamic equations obtained for opinion dissemination, are analyzed theoretically. In addition, for individual opinions and collective opinions,some conditions for reaching negative consensus and positive consensus as well as the theoretical expression for the dissemination threshold are put forward. Numerical simulations are carried to verify the feasibility and effectiveness of the proposed theoretical results, as well as the influence of the intra-structure, inter-connections, and higher-order interactions on the dissemination and evolution of individual opinions. The main results are as follows.(i) When the intra-structure of the collective-opinion layer meets certain characteristics, then a negative or positive consensus is easier to reach for individuals.(ii) Both negative consensus and positive consensus perform best in mixed type of inter-connections in the two-layer network.(iii) Higher-order interactions can quickly eliminate differences in individual opinions, thereby enabling individuals to reach consensus faster.

Nuclear magnetic resonance experiments on the time-varying law of oil viscosity and wettability in high-multiple waterflooding sandstone cores

A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2spectrum,and the time-varying law of simulated oil viscosity in porous media is quantitatively characterized by nuclear magnetic resonance(NMR)experiments of high multiple waterflooding.A new NMR wettability index formula is derived based on NMR relaxation theory to quantitatively characterize the time-varying law of rock wettability during waterflooding combined with high-multiple waterflooding experiment in sandstone cores.The remaining oil viscosity in the core is positively correlated with the displacing water multiple.The remaining oil viscosity increases rapidly when the displacing water multiple is low,and increases slowly when the displacing water multiple is high.The variation of remaining oil viscosity is related to the reservoir heterogeneity.The stronger the reservoir homogeneity,the higher the content of heavy components in the remaining oil and the higher the viscosity.The reservoir wettability changes after water injection:the oil-wet reservoir changes into water-wet reservoir,while the water-wet reservoir becomes more hydrophilic;the degree of change enhances with the increase of displacing water multiple.There is a high correlation between the time-varying oil viscosity and the time-varying wettability,and the change of oil viscosity cannot be ignored.The NMR wettability index calculated by considering the change of oil viscosity is more consistent with the tested Amott(spontaneous imbibition)wettability index,which agrees more with the time-varying law of reservoir wettability.

Ultrasound-guided paravertebral nerve block anesthesia for percutaneous endoscopic laser unroofing treatment of symptomatic simple renal cysts—An innovative ambulatory surgery mode

Objective:This study was designed to evaluate the feasibility,efficacy,and safety of percutaneous ureteroscopy laser unroofing as an ambulatory surgery for symptomatic simple renal cysts under multilevel paravertebral nerve block anesthesia.Methods:From December 2015 to September 2017,33 simple renal cyst patients who had surgical indications were enrolled.Under ultrasound guidance,the T10/T11,T11/T12,and T12/L1 paravertebral spaces were identified,and 7-10 mL 0.5%ropivacaine was injected at each segment.Then a puncture needle was placed inside the cyst cavity under ultrasonic monitoring.A guidewire was introduced followed by sequential dilation up to 28/30 Fr.The extra parenchymal portion of the cyst wall was dissociated and incised using a thulium laser,and a pathological examination was performed.Results:Sensory loss to pinprick from T8 to L1 and sensory loss to ice from T6 to L2 were observed in all patients.None of the patients complained of pain during surgery.No serious complications occurred perioperatively.After the surgery,all patients recovered their lower limb muscle strength quickly,got out of bed,resumed oral feeding,and left the hospital within 24 h of admission.The pathologic diagnosis of all cyst walls was a simple renal cyst.The mean follow-up was 35.8 months.At the end of follow-up,the cyst units were reduced in size by more than 50%compared to the preoperative size,and no patient experienced a recurrence.Conclusion:Multi-level paravertebral nerve block for percutaneous ureteroscopy laser unroofing as an ambulatory surgery mode is feasible,safe,and effective for the treatment of simple renal cysts in selected patients.

Extraction,chemical components,bioactive functions and adulteration identification of walnut oils:A review

Walnut oil is a functional wood oil known to researchers that may potentially be a large source of Chinese edible oils.There are various extraction methods for walnut oil,including traditional(pressing,solvent-and enzymeassisted extraction)and novel methods(microwave,ultrasound,supercritical CO_(2),subcritical and other extraction technologies).Walnut oil is rich in nutrients,including phytosterols,tocopherols,polyphenols,squalene and minerals.It provides many health benefits,such as antioxidant,antitumor,anti-inflammatory,antidiabetic and lipid metabolism-related functions.In addition,the authentication of walnut oil has received much research attention.The present review provides detailed research on walnut oil extraction,composition,health benefits and adulteration identification methods.The path toward further walnut oil improvement in the context of the market value of walnut oil is also discussed.

急性重症脑梗死静脉溶栓患者预后影响因素的分析

目的观察新发的重症脑梗死患者溶栓前后动态脑电图的变化,为重症脑梗死患者的预后提供参考。方法选取2015年1月—2016年12月于乐山市人民医院就诊的符合重组组织型纤溶酶原激活剂静脉溶栓标准的98例重症脑梗死患者,监测患者动态脑电图溶栓前后脑电波的变化。详细记录患者的一般资料、溶栓前后脑电图及头颅影像学检查结果。用Excel建立数据库,应用单变量和Logistic回归分析判断重症脑梗死患者的预后。结果两组患者年龄、发病至就诊时间、脑电图检查及头颅影像学检查结果比较,差异有统计学意义(P<0.05);多因素Logistic回归分析显示,重症脑梗死患者年龄≥65岁[Ol^R=2.958(95%CI:1.347,6.495)]、发病至就诊时间>3.5 h[Ol^R=3.643(95%CI:0.563,5.267)]脑电图检查阳性[Ol^R=4.079(95%CI:1.588,10.477)]、头颅影像学检查阳性[Ol^R=3.021(95%CI:1.554,5.870)]是预后差的独立危险因素。结论入组前年龄>65岁、溶栓后脑电图波形异常及头颅影像学检查结果异常是重症脑梗死患者预后差的独立危险因素。将动态脑电图监测应用于重症脑梗死患者重组组织型纤溶酶原激活剂静脉溶栓,对于预测重症脑梗死患者的预后具有重大意义。

双交联型泡沫凝胶的制备及其暂堵压井防漏机理

针对低压储层修井防漏技术难题,研发了一种双交联型泡沫凝胶压井液,基本配方为:3%聚丙烯酰胺+2%起泡剂+1.5%交联剂A+0.1%交联剂B。显微镜观察表明,单一交联型及双交联型泡沫凝胶均具有明显双膜结构,但双交联型泡沫凝胶膜更厚实,气核最外层凝胶膜厚度最大为77.35μm,气核外层液膜总厚度最大为188.48μm,表现为较好抗压强度和稳定性,其稳定时间大于10d,远高于单一交联型体系。流变性与黏弹性测试表明,双交联型泡沫凝胶具有高弹低黏特征,利于泵送和后期返排解堵。暂堵压井模拟实验表明,对于渗透率在90~208mD的中高渗岩心,在2MPa正压差下60min内作用于岩心的压降值≤0.05MPa,滤失量几乎为零,该双交联型泡沫凝胶压井液具有一定抗压能力与低滤失特性,能有效暂堵储层,在低压油气井修井防漏领域具有较好应用前景。

城市地下空间工程专业就业结构与实践教学优化

实践教学环节作为应用型本科专业培养的重要组成部分,其有效执行程度与毕业生初次就业后的工作适应性密切相关.以安徽理工大学城市地下空间工程专业为例,统计分析了往届毕业生的初次就业结构,结合实践教学中存在的问题,提出了实践教学的优化方案,为类似条件城市地下空间工程专业实践教学提供参考.

Analysis and Prediction Model Reinforced UHPC Shrinkage Property

This paper explores the shrinkage of reinforced UHPC under high-temperature steam curing and natural curing conditions.The results are compared with the existing shrinkage prediction models.The results show that the maximum shrinkage strain of reinforced UHPC after steam curing is 164μεand gradually becomes zero.As for natural curing,the maximum shrinkage strain is 173μεand the value stabilizes on the 10th day after pouring.This indicated that steam curing can significantly reduce shrinkage time.Compared with the plain UHPC tested in the previous literature,the structural reinforcement can significantly inhibit the UHPC shrinkage and greatly reduce the risk of cracking due to shrinkage.By comparing the results in this paper with the existing models for predicting the shrinkage strain development,it is found that the formula recommended in the French UHPC structural and technical specification is suitable for the shrinkage curve in the present paper.

基于流线聚类人工智能方法的水驱油藏流场识别

以某碳酸盐岩油藏注水开发为例,提出针对流线模拟结果的流场识别方法。在流线模拟计算完成后,利用基于Ocean平台自行编写的插件将流线数据导出,并通过Python编程语言进行后续数据处理及聚类分析,直观反映不同开发阶段水驱油藏流场分布。采用密度峰值聚类算法作为流线聚类主要算法,以轮廓系数算法作为聚类评价算法,选取合理的聚类数,并对不同聚类算法结果进行对比。当聚类数相同时,密度峰值聚类算法比K-means、层次聚类、谱聚类算法对不同类型流线区分能力更强且轮廓系数较高,说明了算法的有效性。依据流线聚类结果可对流场进行量化处理,有效识别油藏中无效注水循环通道以及具有开发潜力的区域,同时可对同一注采井间流线进行细分,描述注采井间水相驱动能力大小分布,为注水优化、井网层系调整、深部调剖等方案决策提供依据。

多龄期钢框架结构地震损伤模型研究

基于ABAQUS非线性有限元分析,通过控制变量法分析得出影响多龄期钢框架地震损伤的主控因素为构件有效截面收缩与钢材极限强度退化。定义广义的锈蚀损伤,并探索锈蚀损伤与未锈蚀原型结构地震损伤的关系,最后建立基于未锈蚀原型结构地震损伤的多龄期结构地震损伤模型。

南阳市经济增长、能源消费与碳排放的关系研究及Tapio脱钩分析

以南阳市1994—2016年的GDP与能源消费数据为样本,通过碳排放系数法估算出每年的碳排放量,分析了南阳市能源消费与碳排放之间的关系状态,并采用Tapio脱钩分析法对碳排放与GDP的关系进行了研究.结果表明,南阳市能源消费与碳排放之间呈多元化表现状态;南阳市GDP与碳排放存在不稳定的脱钩关系,绝大多数处于弱脱钩状态或强弱交替脱钩状态,但尚未实现GDP增加而碳排放量降低的目标.因此,对南阳市能源政策的建议是通过加强低碳产业体系和低碳能源体系构建以进一步优化能源结构,通过建立减排长效机制进一步加强对工业和交通领域碳排放的控制,从而逐步实现南阳市GDP与碳排放的强脱钩关系.

上海与香港公园体育设施配置标准比较研究

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