油页岩原位裂解止水注浆实验及数值模拟研究

发布时间：2018-03-18 05:25

本文选题：油页岩　切入点：原位裂解　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：油页岩原位裂解需要通过压裂方式为热载体及油页岩裂解产生的页岩油气提供可以运移的通道。油页岩原位裂解技术需要在一种高温高压的条件下进行,油页岩裂解时反应区域外的地下水难免通过水力压裂产生的裂隙进入反应区域造成热介质大部分热量被地下水吸收而影响油页岩的裂解,另外,油页岩裂解产物随地下水迁移到外界环境中会造成土壤及水环境的污染。针对以上问题本文提出一种油页岩原位裂解止水注浆封闭技术及注浆材料配方,意在为油页岩原位裂解提供一个封闭空间避免以上问题的发生,进而提高能量利用率,减少油页岩原位开采对环境的污染。本文首先对油页岩裂隙的形成过程及形态进行了分析,认为农安油页岩压裂后裂隙大多以平行于油页岩层理方向存在,裂隙高度大多数为0.16mm,且裂隙中存在大量支撑剂。与普通裂隙不同此时的油页岩裂隙类似于多孔介质。由于油页岩原位开采工艺需要在高温高压下的环境中进行,且油页岩裂隙小于0.2mm,此条件下普通硅酸盐水泥注浆材料及化学注浆材料并不适合用于油页岩裂隙注浆施工。经过初选确定了注浆材料配方组成为特种超细水泥、微硅、羟丙基甲基纤维素、葡萄糖酸钠。通过四水平三因素正交试验对配方浆液的析水率、结石率、粘度、浆液流变性能、结石体单轴抗压强度进行了测试与分析,最终确定了最优配方为微硅掺量为10‰,羟丙甲基纤维素掺量为0.6‰,葡萄糖酸钠掺量为0.6‰,水灰比为0.8。利用FLUENT对配方浆液在油页岩裂隙中的扩散规律进行了研究。实际油页岩层注浆施工中,为了防止在反应区域周围注浆时浆液通过裂隙进入到反应区域将反应区域的裂隙堵塞影响油页岩原位裂解进程,需要在注浆的同时继续注高压气体。因此在数值模拟时考虑了注气压力对浆液扩散半径的影响,数值模拟研究水灰比、注浆压力、裂隙高度及注气压力对浆液扩散范围的影响。将含有支撑剂的裂隙简化为多孔介质模型,经过大量的数值模拟确定以上因素对浆液的扩散均有影响,其中注浆压力、水灰比和注气压力对浆液扩散半径影响较大。注浆时由于高压气体的作用浆液扩散呈扇形分布,分布的形状与注气压力和注浆时间有关。裂隙高度为0.16mm,水灰比为1.2,注浆压力为0.8MPa,注气压力为0.8MPa时,注浆时间为20min浆液最大扩散半径为0.57m,最小扩散半径为0.28m。为取得农安油页岩基地注浆施工所需的地下水文资料,使用高密度电阻率法和井间弹性波CT两种方法对农安油页岩基地进行了物探,结果表明在测线160m~420m内存在明显的富水构造,该构造NE40°左右。通过对项目区周围地下水调查获知地下水自西南向东北方向流动,流动方向大约北偏东42°。针对调查结果对项目区止水注浆方案进行了设计,提出了一种油页岩原位裂解封闭式止水注浆技术,此项技术主要内容是在项目区开采区域迎水方向上游设立封闭式止水帷幕注浆区,在油页岩底板及顶板进行注浆形成一个封闭的区域。根据压水试验获得的岩层的透水率及室内试验所测的配方浆液的参数对注浆施工的扩散半径、注浆孔位的距离及布置进行了设计。根据封闭式止水注浆技术的设计方案,在农安油页岩原位开采先导试验工程基地进行了止水注浆试验。通过I序、II序注浆孔的施工对油页岩底板、油页岩层、油页岩顶板进行了为期20天的注浆施工,施工结束后对试验区各段岩层透水率进行了检测,检测结果表明试验区内的各段岩层透水率大幅度下降,注浆止水效果明显,达到了止水注浆形成封闭系统的目的。
[Abstract]:In situ pyrolysis of oil shale to shale oil and gas by fracturing as heat carrier and oil shale pyrolysis production provides the migration channels of oil shale in situ pyrolysis technology is required in a high temperature and high pressure conditions, the oil shale pyrolysis reaction area of groundwater through hydraulic fracturing is generated into the reaction zone caused by thermal crack most of the heat medium absorbed by groundwater and the influence of oil shale pyrolysis, in addition, rock pyrolysis products of oil shale with the groundwater migration to the external environment will cause soil and water pollution. In view of the above problems, this paper presents a closed pyrolysis of oil shale in-situ sealing grouting formula technology and grouting material, is intended to provide a closed space to avoid the above the problem for oil shale in situ pyrolysis, and improve energy efficiency, reduce the oil shale in situ mining firstly, the pollution of the environment. The formation process and morphology analyses of oil shale fractured, fractured shale fracturing that Nongan oil shale mostly existed in the direction parallel to the slit height, for the majority of 0.16mm, there are a lot of proppant and fracture. The fracture is different from ordinary oil shale fracture is similar to porous media. Because of the oil shale in situ the mining process needs under high pressure and high temperature environment, and oil shale fracture is less than 0.2mm, under the condition of ordinary portland cement grouting material and chemical grouting material is not suitable for oil shale fracture grouting construction. After the primaries to determine the grouting material composition for special superfine cement, silicon, hydroxypropyl methyl cellulose, sodium gluconate. Through the analysis of water four factors and three levels orthogonal test of formula of slurry rate, stone rate, viscosity, rheological properties of the slurry, the uniaxial compressive strength of stone body for testing With the analysis, and ultimately determine the optimal formula for silicon content is 10 per thousand, hydroxypropyl methyl cellulose content was 0.6 per thousand, the dosage of sodium gluconate was 0.6 per thousand, the water cement ratio is 0.8. by FLUENT studied diffusion formula of slurry in oil shale fracture. The actual oil shale layer grouting construction in order to prevent, in the reaction zone around the grouting through cracks into the reaction zone will reflect regional fracture blocking effect of oil shale in-situ pyrolysis process, need to continue to inject gas at high pressure grouting at the same time. So the numerical simulation considering the gas injection pressure of grout diffusion radius, numerical simulation of water cement ratio, grouting the pressure effect of fracture height and gas injection pressure of slurry diffusion range. Containing proppant fracture is simplified as porous media model, after a large number of numerical simulation to determine the above factors on slurry diffusion were The effects of grouting pressure, water cement ratio and gas injection pressure of grout diffusion radius of influence. When grouting slurry due to high pressure gas diffusion fan-shaped distribution, shape distribution and gas injection pressure and grouting time. The fracture height is 0.16mm, water cement ratio is 1.2, the grouting pressure is 0.8MPa, the gas injection pressure 0.8MPa, grouting time is 20min maximum grout diffusion radius is 0.57M, the minimum radius of 0.28m. diffusion into underground hydrological data with the required oil shale base grouting Nong'an, using high density resistivity method and cross hole elastic wave CT two method of geophysical exploration of oil shale agricultural base, results show that there is abundant water the obvious in line 160m~420m, the construction of NE40 degrees. Learn the groundwater flow from the southwest to the northeast direction through the surrounding of groundwater investigation, flow direction about the North East 42 degrees. According to the investigation. The fruit of the project area water grouting scheme was designed, put forward a kind of oil shale in situ pyrolysis of closed type sealing grouting technology, the main contents of this technology is the establishment of a closed curtain grouting project area in the upstream mining area in the water direction, floor and roof of oil shale in grouting to form a closed area. According to the measured parameters of slurry diffusion radius formula of permeability and indoor test water pressure test of rock in grouting construction, distance and arrangement of grouting hole is designed. According to the design scheme of sealing grouting technology is closed, the sealing grouting test in Nongan oil shale in situ mining pilot project base. Through the I sequence, II sequence and construction of grouting holes of oil shale oil shale oil shale layer, floor, roof of grouting construction for a period of 20 days, the rate of each test area after the construction of permeable strata The test results show that the permeability of each section in the test area is greatly decreased, and the effect of grouting is very obvious, which achieves the purpose of sealing the system by water injection and grouting.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD83

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