特高含水期井间非均质模式对注水效果的影响

在特高含水期,井间的非均质模式对注水效果有较大的影响。应用渗流力学理论,建立了一维两相流井间非均质数学模型,研究了特高含水期井间非均质模式对注水效果的影响。模型中,渗透率从油井向水井分为降低和升高2种情况;油井端含水饱和度低于水井端的含水饱和度。岩石和流体参数都划分为油井端、中间端和水井端3段。研究结果表明:特高含水期由于注水井端含水饱和度较高,而水相黏度较小,因此水井端渗透率变化引起的渗流阻力变化较小;水井端渗透率降低使油水井两端渗流阻力分布更均衡;特高含水期低注高采能获得更高的产液速度,油水流度的差异是引起这一现象的关键原因;高注低采可在油井端获得更高的压力梯度,从而能取得更好的开发效果。

Influence of interwell heterogeneity mode on water flooding effectiveness at high water cut stage

lnterwell heterogeneity mode will cause a great impact on water flooding effeet at high water cut stage. Interwell heterogeneity mathematical model of one-dimensional two-phase flow was established and influence of interwell heterogeneity mode on water flooding eftectiveness at high water cut stage was studied with permeation fluid mechanics. Permeability may be dividedinto two conditions from producer to water well and the water saturation of oil well is lower than that of water well. Rock and fluid parameters are divided into oil well part, middle part and water well part in this model. The result indicated that change of seepage resistance around injector caused by change of permeability is small because the water saturation around injector is high at high water cut stage and the viscosity of water phase is less. Distribution of seepage resistance between producer and injector will bemore balanced with the decrease of permeability around injector. High rate of producing fluid will be achieved because of low injection and high production at high water cut stage. Difference of oil-water mobility ratio is the key factor to cause this phenomenon. Large pressure gradient can be achieved in production well with high injection and low production, so better development effect can be acquired.