摘要
采用一套系统的模拟地层上覆压力、模拟油藏原始状态的加压方式及加压后物性平衡时间确定的实验方法,进行低渗透砂岩压力敏感性对开采速度的影响实验研究。通过模拟油田实际开采中压力变化过程,对比研究急速改变有效应力与慢速改变有效压力对储层岩石物性的影响,分析低渗透储层物性参数孔隙度、渗透率随有效应力变化规律及压力敏感性特征,进而研究储层压力敏感性对低渗透油藏开采速度的影响。研究表明:即使低渗透储层孔隙度只发生微小损失,将引起岩石的渗透率显著降低,且其受加压方式影响较大,有效压力增加速度越快,岩心渗透率降低幅度越大,不可逆的渗透率损失越大;反之,有效压力增加速度越慢,岩心渗透率降低幅度越小,不可逆渗透率损失越小。建议在开发低渗透油田时采取多次逐级降低井底流压、保持合理的开采速度,以提高最终采收率。
This paper adopts a set of systematic experimental methods that simulate the overburden pressure, simulate the ways of pressurization for the originally state of reservoir, and ascertain the equilibrium time for physical properties after pressure to study the effect of pressure sensitivity on production rate in low permeability sandstone in laboratories. It aims to research the effect of pressure sensitivity on production rate in low-permeability sandstone formation based on simulating the pressure change in real oilfield production, comparing the different effect of rapid-changing effective pressure and slow-changing effective pressure on reservoir petrophysics, and analyzing the porosity of the physic parameters in low permeability formation and the changing law of permeability with the effective pressure as well as the characteristics of pressure sensitivity. The research shows that rocks permeability will see a dramatic decrease even if there is little loss in the porosity of low permeability formation, which is greatly influenced by the ways of pressurization. The more rapidly the speed pressure increases, the more the rate of core permeability reduces and the more the inconvertible permeability loses. Instead, the more slowly the speed pressure decreases, the less the rate of core permeability reduces and the less the inconvertible permeability loses. It is suggested that multi-stage sequential decrease of flowing bottom-hole pressure be employed and rational exploitation velocity be kept to increase ultimate recovery rate during developing low permeability oilfield.
出处
《石油钻采工艺》
CAS
CSCD
北大核心
2007年第1期69-71,共3页
Oil Drilling & Production Technology
基金
国家973项目"低渗透油藏提高采收率基础理论研究"(2002CCA00700)部分研究成果
关键词
低渗透
压力敏感性
有效压力
开采速度
low-permeability
pressure sensitivity
effective pressure
exploitation velocity
