海上陆相非均质油藏水驱波及系数计算

Calculation Method and Application of Plane Sweep Coefficient in Offshore Continental Heterogeneous Reservoir

为指导海上陆相非均质油藏开发,研究了水驱平面波及系数计算问题。首先,采用流管法计算均质油藏的平面波及系数,基于数值模拟技术等效计算油藏非均质校正系数;然后,通过非均质校正系数对均质油藏的平面波及系数进行修正,从而得到非均质油藏的平面波及系数。研究表明:当注采井距一定时,平面波及系数随含水率的上升而增大,且当含水率大于90%时增速加快;当含水率一定时,平面波及系数随注采井距的加大而减小;平面波及系数随渗透率级差的增大而减小,随井网密度的增大而增大。基于此认识,对秦皇岛32-6油田的井网、注采距、采油速度、水驱采收率作了调整,改善了中高含水期的开发效果。

For offshore continental heterogeneous reservoir,the flow tube method is used to calculate the plane sweep coefficient of water drive.The reservoir heterogeneity correction coefficient is introduced to characterize the influence of the heterogeneity on the reservoir plane sweep coefficient,and the reservoir heterogeneity correction coefficient is calculated equivalently based on the reservoir numerical simulation technology.Then,the plane sweep coefficient of the homogeneous reservoir is modified by the heterogeneity correction coefficient to obtain the plane sweep coefficient of the heterogeneous reservoir.The results show that when the injection-production well spacing is constant,the plane sweep coefficient increases with the water cut increasing.When the water cut exceeds 90%,the growth rate of the plane sweep coefficient becomes faster with the increase of the water cut.When the water cut is constant,the larger the injection-production well spacing,the smaller the plane sweep coefficient;The plane sweep coefficient decreases with the increase of permeability gradient and increases with the increase of well pattern density.Based on this understanding,the well pattern,injection-production interval,oil recovery rate and water drive recovery factor of Qinhuangdao 32-6 Oilfield have been adjusted,and the development effect in the middle and high water cut period has been improved.