【作者】 黄河福；

【导师】 王瑞和；

【作者基本信息】 中国石油大学 ， 油气井工程， 2007， 博士

【摘要】 矿渣MTC固井液在性能、经济以及环保上的优势使得其一问世就得到了大家的广泛关注。对矿渣MTC的研究取得了阶段性的成功,使其应用越来越广泛,但还存在许多机理研究和韧性问题的不足,限制了矿渣MTC技术的发展及推广应用。为此,本文进行了理论与实验研究的探讨。利用X射线衍射物相分析方法研究了矿渣和膨润土的物质组成以及矿渣MTC不同水化阶段主要生成物的变化情况,并结合硅酸盐化学方面的理论得到了矿渣MTC水化机理。矿渣MTC水化实质是利用激活剂破坏矿渣中的玻璃体,使得矿渣中的水泥熟料物质可以充分水化;并且矿渣MTC中的SiO₂在强碱存在的条件下,水化生成活性的SiO₂,形成的聚[SiO₄]^4-四面体结构,有助于矿渣MTC凝固体的胶结;另一方面SiO₂本身可以与水泥熟料水化后产物Ca（OH）₂反应生成低C/S的C-S-H凝胶。实验研究得出:增加泥浆的加量,可以提高矿渣MTC的抗压强度,为矿渣MTC用于处理废弃泥浆提供了理论依据和实验基础;矿渣MTC可以与泥饼能够实现整体固化胶结;MTC固化体的体积收缩率远远小于水泥的体积收缩率;而且井壁界面性质对MTC固化体的二界面胶结强度影响较小,从化学反应分析入手理论上得出了矿渣MTC具有低收缩率的原因并得出了矿渣MTC提高固井第二界面理论。利用X射线粒径分析仪得出了矿渣、微硅、漂珠三种颗粒的粒径分布情况,并结合紧密堆积理论和前面得出的活化SiO₂提高矿渣MTC强度理论,通过大量的实验研究得到了低密高强矿渣MTC体系,并完善了低密高强矿渣MTC理论。碳纤维在不同温度条件下都具有提高矿渣MTC固结物抗折强度的能力。矿渣MTC凝固体在1年的时间内其强度在逐渐增加,1年后其强度有缓慢的降低。实验得出矿渣MTC在高温（实验的最高160℃）养护条件下,强度会随着养护时间的延长而不断增大;而波特兰水泥则在养护温度超过110℃之后,强度随养护时间而不断降低。在前人对耐高温水泥研究的基础上,结合矿渣MTC的水化过程可以得出:矿渣MTC具有好的耐高温性能。而且,低C/S的C-S-H凝胶具有较低的碱性并且水化产物Ca（OH）₂的消耗解释了实验得到的矿渣MTC具有较好的耐酸、镁离子和硫酸根离子侵蚀能力的原因。在现场的研究证明矿渣MTC固井技术可以用于长封固段、易漏层段以及不规则井眼等波特兰水泥难以克服的复杂条件下的固井施工,并能取得很好的固井质量。更多还原

【Abstract】 Slag MTC cementing system has been extensively concerned owing to its advantage on performance, economically and environmentally. Though the study of MTC slurry has got episodic succeed, but there are still many aspect to be improved, and that restrict its development and popularized. Here is some theory and experiment research for MTC technology.The constitute of mineral slag and bentonite and the change of slag MTC system during different hydration phase was analysed by XRD, as well slag MTC systerm hydration mechanism was studied on the basis of the chemical theory of silicate. During the hydration of slag MTC, cement clinker can be hydrated completely, as a result of the decomposition of vitreum, SiO₂ can be hydrated to active SiO₂ which can also be named [SiO₄]^4- under strong caustic surrounding. The active SiO₂ can be polymerized to tetrahedron which is beneficial to the cementation of MTC slurry congelation; alternately SiO₂ can react with Ca（OH）₂ and get C-S-H gel with low C/S ratio.The experiments shows that compressive strength can be improved by increasing the addition of the mud, the essential constituent of waste mud is similar to the components of the mud which provide theory criteria and emperiment basis. On the solidification of mud cake and the rate of volume contraction of MTC slurry and simulated experiments on the two-interface showed, MTC slurry can be entirely solidified with mud cake; the rate of volume contraction of solidified MTC was far less than the same rate of cement; the interface quality of wellface had less effect on the bonding strength of the MTC solidification. The reason for the low rate of volume contraction of MTC slurry was studied on chemical reaction. How the MTC slurry can improve the second contact surface, including the solidification of mud cake and undisplaceable mud in of two-interface system, and the low contraction rate of MTC slug. The size distribution of slag, micro-silicon and hollow microsphere was analysed by X ray granulometric analyzer, in combination with the theory of close packing and active SiO₂ can improve MTC intensity, the light weight and high intensity MTC slurry system was builded and its theory was completed. The intension of slag MTC congelation was incremental in one year and decreased slowly one year later.Experiments shows that MTC slurry can remain its intensity under high temperature（the peak 160℃） surroundings, which depends on C-S-H gel with low C/S ratio by MTC slurry hydration. The acid resistance and resistance to erosion resulting from Mg²⁺ and [SO₄]^2- can be explained by the alkalescency of C-S-H gel with low C/S ratio.In-situ experiments indicates slag MTC cementing technology can be applied to complicated circumstance, such as long interval isolation, leaky formation and unregular wellbore et al and can improve the cementing quality effectively.更多还原