致密气藏体积压裂伤害机理实验研究

发布时间：2018-05-02 21:36

本文选题：致密气藏 + 体积压裂　；参考：《中国科学院研究生院(渗流流体力学研究所)》2015年硕士论文

【摘要】：致密气是目前现实性最好的非常规天然气,将成为我国天然气工业快速稳定发展的重要资源。而致密气主要赋存于低孔、低渗的致密砂岩中,需要通过压裂改造技术才能获得工业气流。目前体积压裂通过全面改造储层和增大渗流面积成为开发致密气藏的有效手段。但在压裂过程中,压裂液在改善油气渗流通道的同时也给储层带来了各种各样的伤害。本文通过室内物理模拟实验,对某地区的致密气藏储层岩心进行了研究,不仅得到了压裂液对致密气藏储层的伤害机理,还得到了不同挤入液量对压裂液伤害机理的影响,以及不同反排阶段的主要伤害机理,这对压裂液在实际过程中的应用以及对压裂液配方的优化,具有一定的指导作用。1、通过X衍射、扫描电镜和恒速压汞实验,对目标储层地质特征进行了研究。研究结果表明,目标储层岩心具有普遍孔隙不发育和少量粒间孔隙等特征,此外,粘土矿物的含量总体来说中等,主要胶结物是高岭石,其他的粘土矿物相对较少,另外,目标储层有效喉道半径很小。2、通过常规驱替实验和核磁共振技术,采用平行样比对方法,定量分析了水敏伤害与粘土吸水量的相关关系,水锁伤害与压裂液滞留量的相关关系,以及水敏、水锁和固相伤害的动态变化规律。研究结果表明,水敏和固相伤害是不可逆不可恢复的伤害,而水锁伤害是一个动态变化的过程,气相反排初期水锁伤害很大,随着反排孔隙体积的增加,水锁伤害得到了很好的解除,最终的水锁伤害很小。3、通过常规驱替实验,以及平行样比对方法,研究了不同挤入液量(1、5、10PV)对水敏伤害、水锁伤害和固相基质伤害的影响。研究结果表明,挤入液量的大小对水锁伤害的影响很小,对固相伤害几乎没有影响,而对水敏伤害的影响很大。一开始水锁伤害是反排初期的主要伤害,但随着挤入液量的增加,水敏伤害增大明显,水敏和水锁伤害共同成为初期的主要伤害；在反排后期,水敏伤害一直是主要的伤害机理。
[Abstract]:Dense gas is the best unconventional natural gas in reality at present and will become an important resource for the rapid and stable development of natural gas industry in China. The dense gas mainly occurs in the tight sandstone with low porosity and low permeability, so it is necessary to obtain industrial airflow by fracturing technology. At present, volume fracturing is an effective way to develop tight gas reservoir by comprehensively reforming reservoir and increasing percolation area. However, in the process of fracturing, fracturing fluid not only improves the flow path of oil and gas, but also brings various kinds of damage to reservoir. In this paper, through laboratory physical simulation experiments, the core of tight gas reservoir in a certain area is studied. Not only the damage mechanism of fracturing fluid to tight gas reservoir is obtained, but also the influence of different amount of squeeze fluid on the damage mechanism of fracturing fluid is obtained. And the main damage mechanism of different backflow stages, which has certain guiding effect on the application of fracturing fluid in the actual process and the optimization of fracturing fluid formula, through X-ray diffraction, scanning electron microscope and constant speed mercury pressure experiment. The geological characteristics of the target reservoir are studied. The results show that the core of the target reservoir is characterized by a general lack of pores and a small amount of intergranular pores. In addition, the content of clay minerals is generally medium, the main cementation is kaolinite, the other clay minerals are relatively few, in addition, The effective throat radius of target reservoir is very small. By conventional displacement experiment and nuclear magnetic resonance technique, the correlation between water sensitive damage and clay water absorption and the relationship between water lock damage and fracturing fluid retention are quantitatively analyzed by parallel sample comparison method. And the dynamic changes of water sensitivity, water lock and solid phase damage. The results show that water sensitivity and solid phase damage are irreversible and irrecoverable damage, while water lock damage is a dynamic process. In the initial stage of gas reverse discharge, the water lock damage is very large, and with the increase of anti-discharge pore volume, The water lock injury was well relieved, and the final water lock injury was very small. The effects of water sensitive injury, water lock injury and solid matrix injury on water sensitive injury, water lock injury and solid phase matrix injury were studied by conventional displacement experiment and parallel sample comparison method. The results show that the amount of water squeeze has little effect on the damage of water lock, but has little effect on the damage of solid phase, but has great effect on the damage of water sensitivity. At first, the water lock injury was the main injury in the initial stage of reverse discharge, but with the increase of the amount of water, the water sensitive injury increased obviously, and the water sensitive injury and the water lock injury became the main injury in the initial stage, but in the later stage of reverse discharge, the water sensitive injury increased obviously. Water sensitive injury has always been the main injury mechanism.
【学位授予单位】：中国科学院研究生院(渗流流体力学研究所)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE377

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