平面非均质油藏水驱开采特征和剩余油分布实验研究

为明确平面非均质性对水驱开采特征和剩余油分布的影响规律,结合冀东油田非均质性强等特点,运用布置饱和度测量电极的平面非均质物理模型,开展不同主流线与渗透率分布之间的夹角对水驱开采特征和剩余油分布的影响研究。实验结果表明:当主流线与渗透率分布夹角增加时,开采时间增加明显,水流通道建立后,孔隙内含水不断增加,油水接触界面也在不断增加,平面波及系数有所上升,见水时间明显延长,产油速度变慢,最终采收率增幅明显;主流线与渗透率分布夹角为0°的模型中,在注入量为0.11 PV时,水开始在采出井突破,当夹角增加到30°时,水突破的注入量为0.35 PV,剩余油主要分布在非均质性引起的驱替死角,渗流阻力较大的局部中低渗带;单一表面活性剂驱并不适用于水窜后的平面非均质油藏,需要采用在强封堵能力调剖体系提高波及系数的基础上提高驱油效率的方式。

Experimental study on oil production characteristics of water flooding and remaining oil distribution in the oilfield of plain heterogeneity

To clarify the influence of plain heterogeneity on water flooding characteristics and remaining oil distribution, the water flooding experiment is carried out. Considering the characteristics of Jidong oilfield heterogeneity, the plain heterogeneity model with measuring electrode is used to conduct the impact of angel between main flowing line and permeability distribution on water flooding characteristics and remaining oil distribution. The results show that when the angle between the main line and permeability distribution increases, mining time increases significantly. After the water channel is established, the number of pores containing water increases, and so does the oil-water contact and plane sweep efficiency. Meanwhile, water breakthrough time slows down obviously, so does oil production rate and the ultimate recovery increases significantly. When the injection volume is 0.11PV, water breaks through to the producer in the model of 0°angel between main flowing line and permeability distribution. And when the angel increases to 30°, the breakthrough time increases to 0.35PV, and it makes the remaining oil distribute in the dead corner caused by the heterogeneity and low permeability zone which has larger flowing resistance. Single surfactant flooding is not suitable to the plane heterogeneous reservoir after water breakthrough, and a method which uses strong plugging profile system to improve the displacement efficiency firstly should be applied, then on this basis the sweep efficiency could be improved with water or surfactant flooding.