摘要
针对大多数低渗透油藏在注水开发过程中效果不理想的情况,注CO_2开发油藏是一种提高驱油效率的有效技术手段。CO_2驱油效率受多种因素影响(渗透率、压力、注入速度、注入方式等)。本文通过三因素三水平的9组CO_2岩心驱替正交物理模拟试验,探讨了渗透率、压力和注入速度对CO_2驱油效率产生的影响,随后采用敏感性分析的方法对三个因素的影响程度做了进一步对比。对试验结果分析得知:渗透率的上升会导致驱油效率的降低,但变化幅度较小,驱油效率的最大差值为1.01%;压力与注入速度的提高均可增加驱油效率,压力变化所产生的驱油效率差异较大,最多可相差15.63%,而注入速度变化最大只可使驱油效率产生1.28%的差值,并且在改变注入速度时还需防止因注入速度过快而导致的过早突破和发生气窜。通过对渗透率、压力和注入速度的敏感性分析,3个因素对最终驱油效率的影响程度如下:压力>注入速度>渗透率。
For most low-permeability reservoirs,the effect is not satisfactory during the water injection development process,injecting CO2 to develop reservoirs is an effective technical means to improve oil displacement efficiency.CO2 flooding efficiency is affected by many factors (permeability,pressure,injection speed,injection method,etc.).This paper studied the effects of permeability,pressure and injection rate on CO2 flooding efficiency by 9 groups CO2 core flooding orthogonal physical simulation experiment with three factors and three levels.Then the sensitivity analysis method was used to compare the influence degree of three factors.It can be known from the analysis of the experimental results:The increase in permeability will result in a decrease in the efficiency of oil displacement,but the magnitude of the change is small.The maximum difference of oil displacement efficiency is 1.01%.The increase of pressure and injection speed can increase the efficiency of oil displacement.The difference in oil displacement efficiency caused by pressure changes is large,it can reach up to 15.63%.But the change in injection speed can only produce a maximum difference of 1.28% in oil displacement efficiency.Furthermore,it should be prevented from premature breakthroughs and gas channeling caused by too fast injection speed.Through the sensitivity analysis of permeability,pressure and injection speed,the order of the influence of three factors on the final displacement efficiency is as follows:pressure>injection speed>permeability.
作者
王世璐
王玉霞
贾凯锋
Wang Shilu;Wang Yuxia;Jia Kaifeng(Department of Geology,Northwest University,Xi'an,Shaanxi710069,China)
出处
《非常规油气》
2019年第2期85-90,共6页
Unconventional Oil & Gas
基金
陕西省科技统筹创新工程计划基金资助项目"陕北致密砂岩油藏CO2驱提高采收率关键技术研究及先导实验"(2014KTZB03-02)资助
关键词
低渗透油藏
CO2驱油效率
敏感性分析
正交试验
low permeability reservoir
CO2 flooding efficiency
sensitivity analysis
orthogonal experiment
