刚玉—莫来石质陶瓷材料及油气压裂支撑剂研究

发布时间：2018-05-25 19:23

本文选题：油气压裂支撑剂 + 低品位铝矾土　；参考：《太原科技大学》2015年硕士论文

【摘要】：油气压裂支撑剂作为一种高强度、高附加值的陶瓷颗粒产品已被广泛应用于石油和天然气的井下水力压裂开采作业中,具有支撑地层岩石裂缝、增加油气导流率的作用。目前关于油气压裂支撑剂材质的研究多以铝矾土为主要原料,然而国内陶粒公司为达到国外优质陶粒的性能指标,大量使用优质铝矾土作为生产原料,放弃对低品位铝矾土的使用。这种“留富弃贫”的开采生产再开采模式,最终导致矾土资源的严重浪费。本文针对陶粒支撑剂在实际生产中存在的问题,先以高品位铝矾土为原料制备刚玉莫来石质块状陶瓷材料作为研究基础,再以低品位四级铝矾土为原料制备了低密度刚玉莫来石油气压裂支撑剂,并分别研究了制备工艺与其微观结构和物理性能之间的关系。实验采用二级铝矾土为主要原料,高岭土为辅料,软锰矿粉为添加剂制备了块状试样。结果表明:软锰矿粉的添加对基体的显微结构、致密程度以及机械强度具有较大影响。当掺入4%的软锰矿粉时,陶瓷烧结试样中莫来石骨架相互交错穿插伴有粒状刚玉相填充骨架间隙,块状材料的体积密度、显气孔率及组织致密性和抗压强度得到提高,材料表现出良好的显微形貌以及物理性能。这是由于软锰矿促进了烧结体中熔融液相的产生,从而填补了气孔以及晶体间空隙;另一方面,Mn4+以及莫来石中的Al3+有着相同的八面体结构和相近的离子半径,在烧结过程中容易形成连续固溶体,同时,Mn4+在高温下转变成Mn2+,形成Mn2Al3(AlSi5O18)晶相,引起了晶格畸变产生固溶强化作用,从而提高了烧结体的机械强度。采用四级铝矾土为主要原料,白云石粉、软锰矿粉为添加剂制备了低密度油气压裂支撑剂。结果表明:陶粒中莫来石晶粒间隙中弥散的颗粒状刚玉相有效填补了晶粒间的空隙,增加了基体的紧密度;锰元素的存在降低了基体的最低共熔温度,提高高温液相的析出能力,降低了试样的开气孔率,改善致密性,从而提高了材料的机械强度。当烧结温度在1520 oC,且掺入3%的软锰矿粉时,陶粒支撑剂的显微形貌良好且物理性能最佳,陶粒的体密度为1.28 g/cm3,视密度为2.82 g/cm3,35MPa闭合压力下的破碎率为2.84%,达到了低密度油气压裂支撑剂的标准。
[Abstract]:Oil and gas fracturing proppant, as a kind of ceramic particle product with high strength and high added value, has been widely used in underground hydraulic fracturing production of oil and gas, which can support rock fracture in formation and increase oil and gas conductivity. At present, bauxite is used as the main raw material in the research of oil and gas fracturing proppant material. However, in order to meet the performance index of foreign high quality ceramsite, domestic ceramsite companies use high quality bauxite as raw material in large quantities. Give up the use of low grade bauxite. This kind of mining mode of "leaving the rich behind and abandoning the poor" will lead to serious waste of bauxite resources. In order to solve the problems existing in the practical production of ceramsite proppant, the corundum mullite bulk ceramic material was prepared with high grade bauxite as the raw material. The low density corundum molybdenum petroleum gas fracturing proppant was prepared from low grade bauxite, and the relationship between the preparation process and its microstructure and physical properties was studied. Using bauxite as main raw material, kaolin as auxiliary material and pyrolusite powder as additive, bulk samples were prepared. The results show that the addition of pyrolusite powder has great influence on the microstructure, densification and mechanical strength of the matrix. When 4% pyrolusite powder was added into the ceramic sintered sample, the interlaced mullite framework with granular corundum phase filled the skeleton gap, and the bulk density, apparent porosity, microstructure densification and compressive strength of the bulk material were improved. The materials show good microstructure and physical properties. This is because the pyrolusite promotes the production of molten liquid phase in the sintered body, thus filling the porosity and the intercrystalline void. On the other hand, the Al3 in limn 4 and mullite has the same octahedron structure and similar ionic radius. It is easy to form continuous solid solution in the sintering process, and at the same time, Mn-4 is transformed into Mn2 at high temperature to form Mn2Al3AlSi5O18) crystal phase, which leads to the solid solution strengthening effect of lattice distortion and thus improves the mechanical strength of the sintered body. Using bauxite as main raw material dolomite powder and pyrolusite powder as additives low density oil and gas fracturing proppant was prepared. The results show that the dispersed granular corundum phase in the grain gap of mullite in ceramsite effectively fills the gap between grains and increases the compactness of matrix, and the existence of manganese element decreases the minimum eutectic temperature of matrix. The precipitation ability of the high temperature liquid phase was improved, the porosity of the sample was decreased, and the densification was improved, thus the mechanical strength of the material was improved. When sintering temperature is 1520 OC and 3% pyrolusite powder is added, the microstructure and physical properties of ceramsite proppant are good. The bulk density of ceramsite is 1.28 g / cm ~ (3) and the apparent density is 2.82 g / cm ~ (3) ~ (35) MPA. The breaking rate is 2.84, which is up to the standard of low density oil and gas fracturing proppant.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.7;TE357.12

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