摘要
基于Backly-Leverett水驱油理论,考虑自发同向渗吸过程润湿相前缘向前推进突破岩心出口端前、后时的渗流阻力差异,建立了考虑重力、毛管力、黏滞力和启动压力梯度的一维低渗岩心同向渗吸数学模型;利用建立的数学模型,通过调整启动压力梯度表达式中油水相系数和指数,当计算得到的渗吸速度与时间的关系曲线与室内同向渗吸实验实测曲线实现较好拟合时,即可得到渗吸过程中启动压力梯度的大小及变化规律。通过对5组渗吸实验结果拟合表明,利用该数学模型能够有效计算自发同向渗吸过程中的启动压力梯度大小,可见该方法的建立对于进一步完善渗吸理论数学模型以及丰富启动压力梯度的计算方法具有重要意义。
Based on the theory of Backly-Leverett water flooding,a one-dimensional low permeability imbibition mathematical model was established,considering the gravity,capillary force,viscous force and threshold pressure gradient,and simultaneously considering the different characteristics of the same direction imbibition resistance between before and after the leading edge of wetting phase breakthrough the outlet,When the calculated curve result of the imbibition rate and time is consistent with the experimental curve result of the imbibition in the same direction the mathematical model was utilized to obtain the values and the changes characteristic of the threshold pressure gradient in the imbibition process by adjusting the coefficient and the index of oil-water phase in the threshold pressure gradient equation.The results of the five groups experiments and calculations show that the mathematical model can effectively calculate the threshold pressure gradient of spontaneous imbibition.It can be seen that the establishment of the mathematical method is of great significance to further improve the theory of imbibition and enrich the calculation method of starting pressure gradient.
作者
尤启东
YOU Qi-dong(Exploration and Development Research Institution,Jiangsu Oilfield Company,SINOPEC,Yangzhou 225009,China)
出处
《科学技术与工程》
北大核心
2023年第14期5978-5987,共10页
Science Technology and Engineering
基金
中石化股份公司重大科技项目(P22080)。
关键词
低渗透
启动压力梯度
自发渗吸
同向渗吸
数学模型
low permeability
threshold pressure gradient
spontaneous imbibition
the same direction imbibition
mathematical model
