高温养护高密度水泥石强度和声学特性研究

发布时间：2018-11-02 14:47

【摘要】：在固井中常会遭遇异常高压气层、高压盐水层和高温高压地层,为了能够压稳地层,常采用抗高温高密度水泥浆体系固井。而高密度水泥浆体系由于其不同的外掺料和复杂的井下高温环境,其内部结构与晶相组成以及水泥浆稳定性都会发生变化,如果以正常密度的水泥石的声学特性反应为标准来评价高密度的水泥石的固井质量,所得到的评价结果是不准确的。室内实验研究了铁粉高密度水泥、磁铁粉高密度水泥和锰粉高密度水泥浆体系的浆体密度、养护温度、水泥石抗压强度、声速和声阻抗等因素之间的关系。研究表明:高密度水泥石的抗压强度和声速均与水泥浆密度呈线性负相关关系;水泥石的声速和声阻抗是综合因素作用的结果,与水泥浆的加重剂类型、水灰比、水泥浆的养护温度等因素都有关系,而不会仅仅与某一种因素呈现相关性;铁粉和锰粉高密度水泥浆体系,水泥石的声阻抗与抗压强度呈良好的线性关系,而磁铁粉高密度水泥浆体系的水泥石声阻抗与抗压强度则呈现良好的二次项关系。同时,进一步研究了高温条件下硅酸盐水泥的水化产物,揭示了不同温度下声波传播变化规律的内在机理。高密度水泥石与常规密度水泥石在声学性质上的差异使得常规密度水泥固井质量评价标准不适于高密度水泥固井质量评价,需要引入一个声波幅度减小系数对其进行修正。通过声学理论分析和实验研究相结合的方式,研究出了高密度水泥声波幅度减小系数Φ与水泥石声阻抗之间的关系,并对影响高密度水泥声波幅度减小系数Φ的因素进行了分析,对高密度水泥固井质量评价标准的选用提供了可靠的建议。
[Abstract]:Abnormal high pressure gas layer, high pressure salt water layer and high temperature and high pressure formation are often encountered in cementing. In order to stabilize formation, high temperature and high density cement slurry system is often used for cementing. However, due to its different admixtures and complex underground high temperature environment, the internal structure, crystal phase composition and slurry stability of the high-density cement slurry system will change. If the acoustic response of cement stone with normal density is taken as the criterion to evaluate the cementing quality of high density cement stone, the evaluation results obtained are inaccurate. The relationship between slurry density, curing temperature, compressive strength, sound velocity and acoustic impedance of iron powder high density cement, magnet powder high density cement and manganese powder high density cement slurry system were studied in laboratory. The results show that the compressive strength and sound velocity of high density cement paste have a linear negative correlation with the cement slurry density. The sound velocity and acoustic impedance of cement stone are the result of comprehensive factors, which are related to the type of cement slurry, water-cement ratio, cement slurry curing temperature and so on, but not only to one factor. There is a good linear relationship between the acoustic impedance of cement stone and the compressive strength of high density cement slurry system of iron powder and manganese powder, while the acoustic impedance and compressive strength of cement paste system of high density cement paste system with magnet powder show a good quadratic relationship. At the same time, the hydration products of Portland cement at high temperature were studied, and the internal mechanism of acoustic wave propagation at different temperatures was revealed. Due to the difference of acoustic properties between high density cement and conventional density cement, the evaluation standard of conventional density cement cementing quality is not suitable for high density cement cementing quality evaluation. It is necessary to introduce a sound wave amplitude reduction coefficient to correct it. By combining acoustic theoretical analysis with experimental study, the relationship between the acoustic impedance of cement stone and the amplitude reduction coefficient 桅 of high density cement acoustic wave is studied. The factors influencing the sound wave amplitude of high density cement are analyzed, and some reliable suggestions are provided for the selection of evaluation standard for cementing quality of high density cement.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE256

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