抑制剂对黏土矿物结合水的影响研究

发布时间：2019-04-20 13:05

【摘要】：井壁失稳问题常造成钻井工程无法正常进行,影响着地质资料的录取、钻井成本、油气田开发进程等,在石油钻井工程领域一直倍受重视。黏土矿物水化引起的岩石力学性质变化是诱发井壁失稳的重要因素,泥页岩地层就是由于此因素井壁垮塌严重。强抑制性钻井液能很好地缓解这一情况出现,延长井壁稳定时间,为高效钻井创造空间,但仍然有一些地质条件较差的地层(泥页岩)难以解决井壁失稳问题。现阶段的力学与化学耦合研究为解决此类问题提供了基础,但在化学作用的定量化研究未有较大突破,所以定量化研究抑制剂对泥页岩水化的影响很有必要。首先通过对泥页岩中主要黏土矿物(蒙脱石、伊利石、高岭石和绿泥石)的等温吸附实验,得到四种黏土矿物亲水特性,其中蒙脱石的吸附结合水能力最强。然后结合膨胀率实验与XRD实验测定了抑制剂对蒙脱石水化分散膨胀与晶层间距的影响。最后用热重分析仪重点研究了抑制剂作用后的黏土矿物与泥页岩中结合水情况,结合得到的实验数据模拟计算了泥页岩结合水量。实验发现黏土矿物吸附结合水是分阶段进行的,可以划分为强结合水、弱结合水、自由水。常规的一维膨胀实验只能表征抑制剂的宏观抑制效果,不能深入分析结合水的抑制情况。XRD实验证实了盐类抑制剂都能进入到蒙脱石晶层间,而聚合物只能包裹在颗粒表层,从晶层间距的抑制效果来看,盐类抑制剂的抑制效果要好于聚合物类。热重分析能深入到结合水层面对抑制剂性能进行研究,探讨了无机与有机类抑制剂不同的抑制机理,同时论证了结合水的性质是区别于自由水赋存在黏土表面。通过与真实泥页岩对比分析发现理论计算的泥页岩结合水量与其偏差不大,具有理论价值。
[Abstract]:Borehole instability often causes drilling engineering not to proceed normally, which affects geological data acquisition, drilling cost, development process of oil and gas fields and so on. It has been paid more and more attention in the field of petroleum drilling engineering. The change of rock mechanical properties caused by hydration of clay minerals is an important factor to induce the wall instability, and the shale formation is due to the serious collapse of the shaft wall. Strong inhibition drilling fluid can alleviate this situation, prolong well wall stability time and create space for high efficiency drilling. However, there are still some formations (shale) with poor geological conditions which are difficult to solve the problem of wellbore instability. The coupling study of mechanics and chemistry at present provides a basis for solving these problems, but there is no great breakthrough in the quantitative study of chemical action. Therefore, it is necessary to study quantitatively the influence of inhibitors on shale hydration. Firstly, through isothermal adsorption experiments on the main clay minerals (montmorillonite, Illite, kaolinite and chlorite) in shale, the hydrophilicity of four clay minerals was obtained, among which montmorillonite has the strongest adsorption-binding water ability. The effects of inhibitors on the hydration and dispersion expansion of montmorillonite and the spacing of crystal layers were measured by the expansion rate test and XRD test. Finally, the binding water between clay minerals and shale was studied by thermogravimetric analyzer, and the binding water quantity of shale was simulated with the experimental data. It is found that the adsorption and binding water of clay minerals can be divided into strong bound water, weak bound water and free water, which can be divided into two stages: strong bound water, weak bound water and free water. The conventional one-dimensional expansion test can only characterize the macro-inhibition effect of the inhibitor, but can not analyze the inhibition of combined water in depth. XRD results show that all salt inhibitors can enter the interlayer of montmorillonite, while the polymer can only be wrapped in the surface layer of the particles. The inhibition effect of salt inhibitors is better than that of polymers. Thermogravimetric analysis (TGA) can be used to study the performance of binding water surface inhibitors, and the different inhibition mechanism between inorganic and organic inhibitors is discussed. At the same time, it is demonstrated that the properties of bound water are different from the existence of free water on the clay surface. Through the comparison with the real shale, it is found that the theoretical calculation of the shale bound water is not much different from the actual shale, which is of theoretical value.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE28

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