【作者】 张景富；

【导师】 俞庆森； 严世才；

【作者基本信息】 浙江大学 ， 物理化学， 2001， 博士

【摘要】 以硅酸盐水泥基础理论及有关研究成果为基础，对嘉华G级水泥在25～200℃温度范围内的水化硬化过程、水化产物组成及形态、显微结构、水泥浆稠化陛能、水泥浆流变性能及水泥石强度性能等进行了深入、系统地研究。详细地分析和评价了温度、外加剂及加量等对上述过程及性能所产生的影响规律及本质，揭示了水泥水化过程与有关主要性能变化间的内在本质联系及温度、外加剂的作用机理。从而达到实现确立嘉华G级油井水泥的强度衰退临界温度及合理加砂量、浆体性能的合理调控原则及外加剂的合理选配等目的。为进一步优选和设计以G级水泥为基础的深井水泥浆体系建立依据。 水泥水化过程、规律及水泥石微观结构方面，在分析总结常温下水泥熟料矿物及普通硅酸盐水泥研究成果的基础上，利用DSC差热扫描仪、X—射线衍射仪及扫描电子显微镜对不同温度等条件下的嘉华G级油井水泥的水化过程、水化产物及显微形态进行了检测分析，提出了随温度升高水泥水化速度加快，并在较高温度下C₃A、C₃S、C₂S放热峰存在相互重叠的趋势；温度超过110℃后，原浆水泥主要水化硅酸钙产物为G₂SH、而加硅砂后在养护24和48小时条件下150℃出现C₅S₆H₅、160℃出现C₆S₆H等产物变化特征与规律；给出了水泥石主要产物的形貌特征及水泥石中产物胶结状态随温度的变化特点；明确了硅砂的界面反应特征、孔隙度变化特点等与温度等条件的密切关系；建立了水泥水化动力学模型及化学反应式；揭示了温度、硅砂及硅砂加量三者对水化过程、产物及结构的影响本质。 在水泥工程性能方面，在总结分析油田常用缓凝剂作用机理的基础上，利用高温高压稠度仪、高温高压流变仪利用超声波强度测试仪、高温高压养护釜及强度计等仪器设备，对不同温度及外加剂条件下水泥浆的稠化性能、流变性能及强度发展及变化规律进行了测试分析。提出了赫切尔—巴尔克莱模式能更精确描述水泥浆流变特性的观点，建立了分析确定流变参数的基本方法及数学计算公式，确立了以赫切尔—巴尔克莱流体为基础的管内及偏心环空轴向层流的分析方法及数学解析式，为进一步实施注水泥水力参数设计提供了基础；总结出了随温度增高，水泥浆稠化时间呈多项式（3阶或2阶）形式下降、流变性参数（屈服应力、稠度系数、流性指数）呈分阶段变化的变化特点及规律等结论；揭示了浆体性能变化与水泥水化过程及外加剂作用机理等的内在必然联系。得出了水泥石存在110℃和150℃两个临界温度强度衰退点的高温强度衰退特征；加入硅砂能有效抑制高温强度衰退，合理加砂量范围为30％～45％；原浆水泥110℃后随养护时间增长强度下降，加砂水泥110～150℃范围内存在二级台阶式强度发育特点及在150℃后强度有突变增长等变化规律。评价了处理剂对于不同温度的适用性。揭示了温度、外加剂对水泥石强度发展及变化的影响本质。更多还原

【Abstract】 Based on foundational theory and researching results of Portland cement, hydration process, composition of hydration products, morphology and microstructure of hydration products in hardening cement paste, thickening property, rheological behavior, and strength property of Jiahua Class G Oilwell Cement are studied systematically and intensively for the range of temperature from 25℃ to 200℃. Nature laws of hydration and some main properties which are affected by temperature, additives and added amount of additives are analyzed and evaluated in detail. The nature relationships between hydration process and main properties are revealed. Acting mechanism of temperature and additives is explained. So critical temperature of strength decline, optimum amount of sand added to cement slurry, rule of properly controlling slurry properties and properly choosing additives are determined for Jiahua Class G Oilwell Cement. For deep well cementing, provided a foundation for optimization and designing appropriate cement slurry composition based on Jiahua Class G Oilwell cementIn process and laws of hydration, morphology and microstructure of hardening cement paste, hydration process, hydration products, morphology and microstructure are tested and analyzed for Jihua Class G cement by using DSC, XRD and SEM based on analyzing and summarizing researching achievements of cement clinkers and portland cement Conclusions such as hydration rate and hydration process can be accelerated with the increase of temperature, and at higher temperatures there are the trend to overlap the exothermic peaks of C₃A, C₃S and C₂S one another are given. And revealed the nature and characteristics of the changes of main hydration products which vary with temperature and silica sand. When temperatures exceed 110 ℃ there are a lot of C₂SH products for pure cement slurry and when added some silica sand to cement slurry there are products C₅S₆H₅ below 150℃ and products C₆S₆H above 150℃. Varying characteristics of morphology, microstructure and binding form of hydration products in hardening cement paste are given. Revealed relations among acting characteristics of silica sard, changing characteristics of porosity and conditions such as temperature, additives etc. Hydration kinetic model and reaction formulas of Class G cement for 25-200℃ temperature range are established Nature of the influence of temperature, silica sand and its amount on hydration process, hydration products and microstructure is presented.In cement engineering properties, thickening time and rheological behavior of cement slurries, growth and change of strength for cementstone are tested and analyzed by using High-Temperature-Pressure-Consistometer, High-Temperature-Pressure-Rheometer, Static Gel Strength Analyzer etc. based on introducing and analyzing the types and action mechanism of retardant which usually used in oil field Conclusions indicated that Herschel-Bulkely model can更多还原