【摘要】 均衡驱替是注水开发井网设计的基本原则。对于以中高角度裂缝发育为主、纵向油层厚度大的潜山油藏,流体重力作用对立体井网均衡驱替有显著的影响。基于渗流理论,以水平井立体五点井网为例,建立了考虑重力作用时生产井见水时间的公式,给出了均衡驱替时注采井距公式,并选取油藏参数计算了均衡驱替时中心水平井的位置;同时,利用数值模拟方法对水平井立体五点井网中心注水井所在的位置进行了优化。结果表明:计算结果与数值模拟优化结果误差为4.73%,在实验允许的范围内,验证了计算公式的可靠性;随着中心注水井逐层上移,纵向上各生产井见水时间差先减小后增大;当注水井S2位于第6层时,生产井S1和S3见水时间差达到最小,实现了均衡驱替,此时采出程度最高,达到42.52%,比S2井位于11层时提高3.84%;均衡驱替时注水井S2到生产井S1和S3的距离之比为2.95。通过调整注水井的位置,减弱了重力作用造成的非均衡驱替,改善了开发效果。更多还原

【Abstract】 Equilibrium displacement is the basic principle for well pattern design in waterflood oilfield. For the case of bur-ied hill reservoir with dominant mid-high angle fractures and large vertical thickness,the gravity of fluid has significant in-fluence on equilibrium displacement in stereo well pattern. Based on percolation theory,taking five-spot stereo horizontalwell pattern for instance,formulas for water breakthrough time of production well considering the gravity and that for injec-tion-production well spacing while equilibrium displacement were established. The place of central horizontal well was cal-culated according to the selected oil reservoir parameters and was optimized using numerical simulation method. The re-sults indicate that the error between calculation and numerical simulation is 4.73% which is allowable in experiment,andthe reliability of the formula is verified. The water breakthrough time difference between vertical production wells decreasesand then increases as the central injection well rises layer by layer. When the injection well of S2 locates in the 6thlayer,equilibrium displacement is realized that the breakthrough time difference between S1 and S3 is the lowest. The degree ofreserve recovery reaches 42.52%,which is the peak value,and is improved by 3.84% compared with that when S2 locatesin 11 thlayer.When the equilibrium displacement is realized,the ratio of injection-production distance from S2 to S1 andthat from S2 to S3 is 2.95. Therefore,well spacing adjustment could improve development by impairing non-equilibriumdisplacement induced by gravitational effect.更多还原