基于分段压裂技术的可溶性材料研究

发布时间：2018-06-08 03:04

本文选题：分段压裂 + 热处理　；参考：《沈阳航空航天大学》2015年硕士论文

【摘要】：水平井分段压裂技术是经济、有效的提高油田采收率和开发低渗透、低孔隙度油藏的主要手段。滑套压裂球作为水平井分段压裂的关键技术具有十分重要的研究意义。本文对构成滑套压裂球原材料的腐蚀原理、抗剪切力学强度的提升和影响镁合金腐蚀速度的内外部因素进行了深入的研究,将以镁合金作为基本原料的滑套压裂球通过对镁合金进行稀土合金化、均匀化热处理、加入高电位元素和低熔点元素等方法提高镁合金的材料性能,使其达到国外同类产品的技术水平。本文根据美国贝克休斯公司的产品可套压裂球(Disintegrating Frac Ball)的宣传资料,对该产品进行了深入的分析,对它的主要成分和工作原理也有了一个初步的了解。并且根据我国镁合金工业水平,通过热处理、稀土合金化等工艺手段,对镁合金的抗压强度和抗剪切强度来进行有效提升,通过实验对比发现稀土合金化后的镁合金在抗剪切强度方面有很大的提高。同时还对影响镁合金的可降解性能的内外在因素进行了深入研究,发现影响镁合金降解速度的外在因素主要有:镁合金所处环境的氯离子浓度、PH值大小、温度的高低和外界应力大小等。而影响镁合金降解速度的内在因素包括冶炼过程存在的杂质与缺陷、对镁合金进行冶炼的工艺过程、内部晶粒的大小与均匀化程度等,并通过改变这些因素,观察这些因素对镁合金降解速度影响的大小。再通过观察稀土镁合金的腐蚀金相图,来了解稀土镁合金的腐蚀过程,从微观上了解到稀土镁合金的腐蚀率先发生在与那些小晶粒相邻的晶界处,并且镁合金的基相是阳极相,镁合金的第二相是阴极相,它们之间发生电偶腐蚀。为了使滑套压裂球能够均匀降解,通过对稀土镁合金在冶炼过程中加入一些高电位元素,和一些低熔点的元素,利用镁合金高温腐蚀和电偶腐蚀的原理加速镁合金的腐蚀,同时发现稀土元素在镁合金腐蚀过程中有改变腐蚀方向的作用,能起到均匀腐蚀的效果。最后,通过对所炼制的新型镁合金进行均匀化热处理,使镁合金内部的晶粒细小,而且分布均匀,使新型镁合金达到均匀降解的效果。
[Abstract]:Horizontal well fracturing technology is an economic and effective way to improve oil recovery and develop low permeability and low porosity reservoirs. As the key technology of horizontal well fracturing, sliding casing fracturing ball is of great significance. In this paper, the corrosion principle of the raw materials of the sliding casing fracturing ball, the promotion of shear strength and the internal and external factors affecting the corrosion rate of magnesium alloy are studied. The sliding casing fracturing ball with magnesium alloy as basic raw material was used to improve the properties of magnesium alloy by alloying magnesium alloy with rare earth, homogenizing heat treatment, adding high potential element and low melting point element, etc. Make it reach the technical level of the same kind of products abroad. According to the propaganda materials of Baker Hughes Company, the product of fracturing ball disintegrating is analyzed in depth, and its main components and working principle are also preliminarily understood. According to the industry level of magnesium alloy in China, the compressive strength and shear strength of magnesium alloy are effectively promoted by heat treatment and rare earth alloying. It was found that the shear strength of rare earth alloyed magnesium alloy was improved greatly. At the same time, the internal and external factors affecting the degradability of magnesium alloy were studied. The main external factors affecting the degradation rate of magnesium alloy were: the concentration of chlorine ions and PH value in the environment of magnesium alloy. Temperature and external stress, etc. The internal factors affecting the degradation rate of magnesium alloy include impurities and defects in smelting process, process of smelting magnesium alloy, internal grain size and homogenization degree, and by changing these factors, The effect of these factors on the degradation rate of magnesium alloy was observed. By observing the corrosion metallography of rare earth magnesium alloy, the corrosion process of rare earth magnesium alloy is understood. From the microscopic point of view, it is found that the corrosion of rare earth magnesium alloy first occurs at the grain boundary adjacent to those small grains, and the base phase of magnesium alloy is anode phase. The second phase of magnesium alloy is cathodic phase, and galvanic corrosion occurs between them. In order to make the sliding casing fracturing ball degrade uniformly, by adding some high potential elements and some low melting point elements in the smelting process of rare earth magnesium alloy, the principles of high temperature corrosion and galvanic corrosion of magnesium alloy were used to accelerate the corrosion of magnesium alloy. At the same time, it is found that rare earth elements can change the corrosion direction of magnesium alloy and play a uniform corrosion effect. Finally, by homogenizing heat treatment of the new magnesium alloy, the grain size is fine and the distribution is uniform, which makes the new magnesium alloy achieve the effect of homogeneous degradation.
【学位授予单位】：沈阳航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357

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