摘要
基于广义达西定律,考虑启动压力梯度影响,建立了渗透率各向异性低渗透油水两相渗流模型,并基于虚位移原理开发了有限元程序,以大庆油区苏仁诺尔油田苏301断块矩形五点线性注采井网为例,分析了启动压力梯度对低渗透油藏微观渗流和宏观开发动态的影响。结果表明:受启动压力梯度的影响,低渗透油藏内渗流速度变化存在显著的延迟效应,渗流速度呈阶梯状变化;启动压力梯度越小,油井初期产油量越高,但后期含水率上升速度越快,油井后期产油量降低幅度越显著;启动压力梯度越大,油藏采出程度越低,且随着生产时间增长,对采出程度影响越显著。
Based on the generalized Darcy' s law, considering the effect of start-up pressure gradient, the permeability anisotropy of low permeability oil-water two phase seepage model is established herein. Based on the principle of virtual displacement, a finite element program is developed. Taking the Daqing Su301 fault block, a rectangular five-spot linear injection-production well pattern as an example, we analyze the effects of start-up pressure gradient on low permeability reservoir micro-seepage and macro development dynamic trends. The research shows that, influenced by start-up pressure gradient effect, the low permeability reservoir seepage has a significant delayed effect, seepage velocity shows a 'ladder shape' changing trend; the smaller the start-up pressure gradient, the higher of the initial oil production, but later the water cut rises up increasingly fast, leading to a much more obvious reduction of daily production; the greater the start-up pressure gradient, the lower the reservoir recovery degree, and along with the producing continues, it has greater influence on reservoir recovery degree.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2013年第1期67-69,73,共4页
Petroleum Geology and Recovery Efficiency
基金
山东省博士后创新项目"疏松砂岩储层应力及出砂界限研究"(201203017)
关键词
启动压力梯度
低渗透油藏
有限元
微观渗流
开发动态
start-up pressure gradient
low permeability reservoir
finite element
micro-seepage
development trends
