过热蒸汽原位热解油页岩开采油气微观特征研究
发布时间：2018-01-21 17:52
本文关键词： 油页岩 注蒸汽 SEM 压汞试验 红外光谱 微观特征 出处：《太原理工大学》2017年硕士论文 论文类型：学位论文
【摘要】：在我国能源结构中煤炭资源所占比重在不断减少,清洁能源所占比例逐步提高,能源的多元化发展是大势所趋。油页岩是非常规油气资源,而且我国油页岩矿藏的储量丰富,故该类资源的开发利用对缓解我国油气能源需求的紧张局势具有重要的现实意义。目前,油页岩原位开采技术得到了大范围的应用,本文以抚顺油页岩为研究对象,在过热蒸汽原位开采油页岩模拟试验的基础上,通过扫描电镜、压汞试验以及红外光谱分析相结合的方法对热解矿层的微观结构和热解规律进行了综合分析,得到的主要研究成果如下:(1)通过SEM方法对抚顺油页岩和新疆油页岩在不同温度下的形貌特征和细观结构进行了对比分析,从而为油页岩的原位注蒸汽开采技术提供一定的实验依据。研究表明,抚顺油页岩矿物质分布以零散分布的高岭石和片状的石英为主,新疆油页岩矿物质分布以鳞片状的蒙脱石和块状的石英为主;随着温度的升高,黏土矿物层发生“脱水~层间破裂~层内张拉脆性破裂”的热破裂过程,而在形态上表现为“粘连~软化~熔融”的特征;抚顺油页岩发生热破裂消耗的能量要低于新疆油页岩,在压裂过程中裂缝发育程度更为明显,有机质热解更为高效。(2)在过热蒸汽原位热解油页岩的过程中,油页岩矿层受到蒸汽压力和地应力的双重作用,通过压汞法对过热蒸汽热解油页岩后岩体内部孔洞特征进行研究,得到了平行于水平主裂缝方向以及垂直主裂缝方向油页岩的孔隙结构、孔隙度以及孔径变化规律:主裂缝上各个位置油页岩孔隙度均处于26.5%以上,孔隙度较大,说明油页岩在注蒸汽开采下孔隙度发生了质的改变;靠近顶板基岩段的矿层孔隙度较低,其热解形式以热传导为主;在主裂缝的各个位置,不同类别孔隙所占百分比表现为:中孔小孔大孔微孔,中孔对孔隙度变化规律的贡献度最大;对油页岩矿层不同位置的孔隙度进行统计,得到充分热解矿层百分比达到了81.6846%,充分证实了注蒸汽原位热解油页岩开采油气的可行性和高效率。(3)通过对过热蒸汽热解后油页岩矿层的渗透特性以及分形规律进行综合分析。研究表明,原位开采下油页岩矿层的有效孔隙率要低于直接干馏热解得到的油页岩有效孔隙率,这主要是受到地应力的影响;主裂缝方向上油页岩孔隙的迂曲度集中在2.15~2.17之间,垂直主裂缝方向上油页岩孔隙的迂曲度集中在2.145~2.165之间,整体上热解矿层的迂曲度较小;通过多元回归分析的方法得到了比表面积、有效孔隙率、迂曲度以及孔隙喉孔比等因素与油页岩渗透率之间的定量关系,同时对不同因素的影响效果进行了进一步对比。(4)本文还对过热蒸汽热解油页岩矿层后不同位置岩体的化学结构演变规律进行了红外光谱分析,认为随着油页岩干酪根的不断热解,一方面,脂肪族化合物官能团不断发生热裂解,另一方面,随着过热蒸汽的不断注入,C=C键的强度被削弱,不稳定的残键之间的电子发生转移,从而生成了新的大π键,提高了芳构化程度;高温高压水蒸气不仅起到热解油页岩的作用,而且在高温下水蒸气与油页岩中的碳酸盐之间发生复杂的化学反应。本文得到的研究结论对过热蒸汽原位热解油页岩技术的发展提供了一定的指导意义。
[Abstract]:In China's energy structure, coal resources proportion is decreasing, gradually increase the proportion of clean energy, diversified development of energy is represent the general trend. The oil shale is unconventional oil and gas resources, and China's oil shale reserves rich, so the development and utilization of resources to alleviate the tensions in the oil and gas energy demand in China has important practical significance. At present, oil shale in-situ technique has been widely used, this paper takes Fushun oil shale as the research object, based on the oil shale in the superheated steam in situ simulation test, through scanning electron microscope, mercury penetration test and infrared spectrum analysis of combining pyrolysis ore microstructure and pyrolysis are analyzed, the main research results are as follows: (1) through the SEM method on the morphology characteristics of Fushun oil shale and Xinjiang oil shale under different temperature And the meso structure were analyzed. The oil shale in situ so as to provide some experimental basis for steam injection technology. The research results show that the distribution of minerals in Fushun oil shale scattered distribution of kaolinite and quartz flake, Xinjiang oil shale mineral distribution in scaly montmorillonite and massive quartz; with the increase of temperature the clay mineral layer, dehydration of the interlaminar fracture layer ~ ~ tensile brittle fracture "thermal cracking process, characteristics and in form" ~ ~ adhesion softening melting "; the energy consumption of thermal cracking is lower than that of the Xinjiang oil shale oil shale in Fushun, in the process of fracturing fracture development degree obviously, organic matter was more efficient. (2) in the process of superheated steam in situ pyrolysis oil shale, oil shale seam is influenced by both the steam pressure and stress, through the mercury method of superheated steam The pyrolysis of oil shale after internal pore characteristics of rock mass are studied, the parallel to the direction of fracture and pore structure of vertical fracture direction of oil shale, porosity and aperture of main crack on each position of the oil shale porosity is above 26.5%, porosity is large, the results showed that oil shale mining porosity occurred in steam injection the change of the quality; near the roof rock strata with low porosity, the pyrolysis in the form of heat conduction; in each position of the main crack, the percentage of different types of pore are as follows: Kong Xiaokong macroporous and microporous, mesoporous contribution to the variation of the maximum degree of porosity; statistics of oil shale deposits in different positions the porosity of full seam pyrolysis percentage reached 81.6846%, fully demonstrated the feasibility of the exploitation of oil and gas injection steam pyrolysis oil shale in situ and high efficiency (3) through. The comprehensive analysis of the seepage characteristics of oil shale deposits of superheated steam pyrolysis and fractal law. The research results show that the effective porosity of oil shale deposits in situ mining of oil shale porosity lower than direct carbonization and pyrolysis, which is mainly affected by the stress; the direction of fracture of oil shale pore tortuosity concentrated between 2.15~2.17. The vertical direction of the main crack of oil shale pore tortuosity between the 2.145~2.165, pyrolysis seam tortuosity smaller on the whole; by multiple regression analysis method to get the specific surface area, porosity, the quantitative relationship between the tortuosity and pore throat ratio and factors such as oil shale permeability, while the effect of different factors a further comparison. (4) the chemical structure of superheated steam pyrolysis of oil shale deposits in different position of rock evolution law 杩涜浜嗙孩澶栧厜璋卞垎鏋，
本文编号：1452160
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