摘要
在油气藏开采过程中,由于地层压力的下降,储层在有效应力的作用下就会发生变形,引起渗透率的变化。文中通过实验研究了天然岩心孔隙体积、孔隙度、克氏渗透率、空气渗透率、岩石压缩系数与净围压的关系。实验结果表明,随着净围压的增加,孔隙体积和孔隙度逐渐减小。但净围压较大时,孔隙度和孔隙体积的下降幅度减小。通过实验测得的克氏渗透率与空气渗透率两组数据可以看出,克氏渗透率小于空气渗透率,说明低渗气藏的确存在滑脱效应,而且滑脱效应受净围压的影响。压缩系数随着净围压的增大而减小,且下降幅度越来越小,这与孔隙压缩规律相似。在此基础上,经理论推导给出了考虑气体滑脱效应和压敏效应的渗流方程。
Permeability is an important parameter of influencing the off-take potential of oil and gas well.Oil layer will be deformed by the actual stress that produced by the descend of reservoir pressure during recovery.In this paper,the relationship of pore volume,porosity,kinkenberg permeability,air permeability,rock compressibility factor with confining pressure was studied through natural core experiments.The results indicated that pore volume,porosity,kinkenberg permeability,air permeability,rock compressibility factor would descend with the increase of confining pressure.Slippage effect would come into being in low-permeability gas reservoir.Flow equation was worked out considering Slippage effect and pressure-sensitive effect.
出处
《钻采工艺》
CAS
北大核心
2007年第6期49-51,共3页
Drilling & Production Technology
基金
科技部973项目(项目编号2001-CB-209-100)
项目名称:"高效天然气藏形成分布规律与凝析
低效气藏经济开发的基础研究"
国家自然科学基金重点资助项目(基金号50634020)
项目名称:"低渗透率油层提高驱油效率的机理研究"
关键词
低渗透
压敏效应
实验
渗流
滑脱效应
low-permeability reservoir,pressure-sensitive effect,experiment,percolation,slippage effect
