【作者】 张虎贲；

【导师】 孙仁远；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2011， 硕士

【摘要】 稠油是一种非常规石油资源,稠油的开发对于缓解我国的能源供应紧张意义重大。蒸汽-CO₂复合驱方法开采稠油,不仅可以提高稠油的采收率,而且可以实现CO₂气体的减排,对减缓全球气候变暖、保护环境具有重要意义。采用自制的PVT装置,研究了CO₂在稠油以及稠油-水体系中的溶解特性,分析了其影响因素。采用高温高压落球粘度计,对稠油、稠油-水体系、稠油-CO₂体系以及稠油-水-CO₂体系的粘度进行了测量,研究了温度、压力、溶解气油比以及含水率对体系粘度的影响。建立了系列一维填砂模型,利用稠油渗流机理研究装置,开展了稠油油藏蒸汽驱、蒸汽-CO₂复合驱以及蒸汽-N2复合驱模拟实验研究,研究了蒸汽注入温度、注入速度、CO₂注入时机、CO₂注入量等因素对稠油采收率的影响,对注入参数进行了优化,并对蒸汽-CO₂复合驱增产机理进行了分析。实验结果表明,稠油及稠油-水的体系泡点压力随温度升高而升高,含水率越高,泡点压力越高。CO₂在稠油、稠油-水体系中的溶解气油比比在稀油中的溶解气油比小,它随温度升高而降低,随饱和压力升高而升高,随含水率升高而降低。稠油、稠油-水体系溶解CO₂后粘度大幅度下降,降幅可达99%。稠油油藏蒸汽驱能提高水驱采收率,降低水驱含水率,并且蒸汽注入速度越大,注入温度越高,采出液含水率越低,采收率越好。相比蒸汽驱,蒸汽-CO₂复合驱可以降低含水率30%,提高采收率30%。CO₂溶解对稠油-水体系有一定的破乳作用,能有效降低稠油粘度,提高蒸汽利用率,增大波及体积,提高采收率。更多还原

【Abstract】 Heavy oil is an unconventional resources, which is of great significance to relieve the tension supply of energy. Steam-CO₂ combination flooding can not only enhance oil recovery, but also reduce the emission of CO₂, which is dramatically meaningful to global warming and environmental protection. The solution properties of CO₂ in heavy oil and heavy oil-water system was investigated, and the factors that influence the solution was analysed by self-made device. The viscosity of heavy oil, heavy oil-water system, heavy oil-CO₂ system and heavy oil-water-CO₂ system were measured by high pressure and high temperature falling sphere viscometer, and the influencing factors such as temperature, pressure, solubility and water ratio were also studied. A series of simulated experiments include steam flooding, steam-CO₂ combination flooding and steam-N2 combination flooding were studied by a lot of sand pack models and the flowing mechanisms apparatus of heavy oil. In addition, the injection parameters which impact oil recovery such as injection temperature, injection rate, CO₂ injection time, CO₂ injection rates was optimized. Stimulation mechanism of steam-CO₂ combination flooding is analysed as well.Experimental results show that the bubble-point pressure of heavy oil and heavy oil-water systems increase with temperature rise and water ratio decline. Solubility of CO₂ in heavy oil and heavy oil-water systems is smaller than that in thin oil, and reduces with temperature rise, water ratio rise and saturation pressure decline. The viscosity of heavy oil and heavy oil-water system decreases up to 99% dissolved by CO₂. Steam flooding can enhance water flooding recovery and reduce water ratio for heavy oil reservoir. As the increasing of injection rate and injection temperature, water ratio of produced fluid decreases and recovery increases. Compared with steam flooding, recovery of steam-CO₂ combination flooding improves up to 30%, and water ratio of produced fluid decreases up to 30%. Solution of CO₂ had demulsification of heavy oil-water systems, reduces viscosity of heavy oil effectively, improves utilization of steam, increases swept volume and enhances oil recovery.更多还原