摘要
特低渗透油藏在压力变化的条件下,通常发生的是不可逆变形。通过推导不可逆变形条件下渗透率与压力的关系,建立了考虑不可逆变形的特低渗透油藏非线性稳定渗流模型并进行数值求解,从而得到了内边界定压和定产量条件下的压力分布。在定压条件下,随着渗透率下降变化系数的增加,地层压力下降得越来越慢,产量也随之下降,极限供油半径越来越小;另外,随着原始地层压力下渗透率的不断降低,极限供油半径逐渐变小,且变化越来越明显;当产量一定时,随着渗透率下降变化系数的增加,地层压力下降得越来越快。最后给出了定压条件下的极限供油半径关于原始地层压力下的渗透率和渗透率下降变化系数的表达式,并将计算值与实际结果进行了对比,两者拟合较好。
With the variation on the formation pressure,the formation deformation is usually non-reversible in the extra-low permeability reservoirs.By analyzing the changing of permeability varies with the pressure under non-reversible deformation condition,the nonlinear steady flow model was established and derived with numerical method.The pressure distribution was determined with constant inner boundary pressure or production.Under the condi-tion of constant pressure,the formation pressure decreases more and more slowly with the permeability drop variation coefficient increasing,and the oil production and limit drainage radius decreases;moreover,the limit drainage radius decreases more and more obviously with permeability at initial formation pressure decreasing.When the oil production is constant,the formation pressure decreases more and more quickly with the permeability drop variation coefficient increasing.Then the mathematical expression of the limit drainage radius was given,which contains permeability at initial formation pressure and permeability drop variation coefficient.Computational solutions were compared with the actual results,both of them matched very well.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2008年第5期78-81,共4页
Petroleum Geology and Recovery Efficiency
基金
中国石油化工股份有限公司科研项目“特低渗油藏渗流机理研究”(P06074)
中国石油大学研究生创新基金资助项目
“泰山学者”建设工程专项经费资助
关键词
不可逆变形
稳定渗流
压力分布
极限供油半径
特低渗透油藏
non-reversible deformation
steady flow
pressure distribution
limit drainage radius
extra-low permeability reservoir
