塔河油田缝洞型油藏注气驱油机理研究

发布时间：2018-03-21 23:26

本文选题：缝洞型油藏　切入点：注气驱油　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳酸盐岩缝洞型油藏在全世界油气资源储量中占据重要地位,具有规模大、储量大、储层非均质性强等特点,在国内外均属难开采油藏,无论从理论方面还是实践方面,此类油藏的勘探开发技术都处于探索阶段,而现有的研究工作还不能满足这类油藏的开发需要。本文以研究缝洞型油藏在水驱失效后进行注气驱油的适应性为目的,通过流体相态特征实验、可视化模型实验和全直径岩心实验等多种研究手段对缝洞型油藏注气驱油机理进行了研究认识。以典型的碳酸盐岩油藏——塔河4区S48单元为例,S48单元在前期生产中主要采用注水开发方式进行开采,但注水开发效果正逐年变差,在缝洞体构造高部位存在大量剩余油,需要转变开发方式。本次论文研究分别从注入气增溶降黏能力、重力分异作用、地层能量分布和缝洞结构条件等四个方面对S48单元注气驱油的作用机理进行分析。在流体相态特征实验中对S48单元地层流体进行了分析,得知地层油样为高含重质组分的黑油,认识N2、CO2、天然气三种不同注入气对地层油样的增溶、降黏和抽提性能的具体差异。在高温高压全直径岩心实验中采用了水驱—气驱—水驱的方式进行研究,通过实验进一步认识到以上三种气体的增溶降黏性能差异对稠油采驱效果的具体影响；然后进行了模型通道封堵和岩心夹持器倾角改变的对比实验,认识到缝洞型油藏注气驱油对“阁楼油”的驱油机理以重力分异作用为主。有机玻璃可视化模型实验同样采用水驱—气驱—水驱方式进行研究,通过对实验流程的直接观察,对缝洞储集体高低分布、开口方向、开口数量以及所连接裂缝的缝宽、发育方向等方面对注气驱油作用机理的影响取得了更为深刻直观的认识。通过深入研究得出结论：缝洞型油藏注水开发失效后,采用注气驱油措施可以有效动用水驱未波及的“阁楼油”,重力分异为主要气驱作用机理,增溶、降黏和抽提等机理影响相对较小,且井间缝洞结构对流体流动路径的具有一定影响。论文成果对缝洞型油藏注气开发技术的发展具有一定的参考价值。
[Abstract]:Carbonate fractured and cavernous reservoirs occupy an important position in the world's oil and gas reserves, and have the characteristics of large scale, large reserves and strong heterogeneity of reservoirs. They are difficult to be exploited both at home and abroad, both in theory and in practice. The exploration and development technology of this kind of reservoir is in the stage of exploration, but the existing research work can not meet the development needs of this kind of reservoir. This paper aims to study the adaptability of gas injection and oil displacement after the failure of water flooding. The mechanism of gas injection and oil displacement in fractured reservoir is studied by means of fluid phase characteristic experiment, visual model experiment and full-diameter core experiment. Taking S48 unit of typical carbonate reservoir-Tahe area 4 as an example, water injection development is mainly used in the early production of unit S48, but the effect of water injection development is becoming worse year by year, and there are a lot of remaining oil in the high structural part of fracture and cavern body. It is necessary to change the development mode. In this paper, we studied the effects of injection gas on solubilization and viscosity reduction, gravity differentiation, The mechanism of gas flooding in unit S48 is analyzed from four aspects, namely, the distribution of formation energy and the structural conditions of fracture and cavity. In the experiment of fluid phase behavior, the formation fluid of unit S48 is analyzed, and it is found that the formation oil sample is black oil with high content of heavy components. It is recognized that the solubilization, viscosity reduction and extraction performance of three kinds of natural gas injected with N _ 2C _ 2CO _ 2 and N _ 2CO _ 2 are different from each other. In the high-temperature and high-pressure full-diameter core experiment, the water-gas driving-water drive method is used to study. Through the experiments, it is further recognized that the difference of solubilization and viscosity performance of the above three gases has a specific effect on the heavy oil flooding efficiency, and then a comparative experiment is carried out on the model channel plugging and the change of the core holder inclination angle. It is recognized that the mechanism of gas-flooding in fracture-cavity reservoirs is mainly due to the effect of gravity differentiation on loft oil. The visual model experiment of organic glass is also studied by water-gas-water-drive mode, and through the direct observation of the experimental process, The effects of high and low distribution of reservoir mass, opening direction, number of openings, fracture width and development direction of the connected fractures on the mechanism of gas injection and oil displacement have been obtained more intuitively. Through in-depth study, it is concluded that gas injection and oil flooding can effectively produce loft oil which has not been affected by water flooding, and gravity differentiation is the main mechanism of gas drive and solubilization. The mechanism of viscosity reduction and extraction is relatively small, and the structure of interwell fracture and cavity has a certain influence on the flow path of fluid. The results of this paper have some reference value for the development of gas injection technology in fracture-cavity reservoirs.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.7

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