反九点井网不同井型对海上油田聚合物驱油效果影响实验研究

在内置微电极三维平面均质岩心模型上进行物理模拟实验,对比研究了反九点井网条件下直井和水平井对开采效果和剩余油分布的影响。在均质条件反九点井网(一注三采)中,边井之一采用水平井开发,水平井所控制的泄油面积大,区域内的剩余油较直井开发动用程度高,水平井单井最终采收率比相同位置直井单井最终采收率高了2.53%;但是整体上改善开发效果不明显。为了进一步研究不同井型对开发效果及剩余油分布的影响,利用数值模拟技术研究了非均质条件下不同水平井布井方式对驱油效果以及剩余油分布的影响。研究结果表明,非均质条件下采用水平井与直井组合开发,效果要好于单纯采用直井开发的模式。不同的水平井布井位置提高采出程度的幅度及动用剩余油的范围又有所差异。当水平井位于低渗带时,能够大范围动用直井开发时不能动用的低渗带剩余油,降低剩余油饱和度,提高采出程度相对较高。当水平井位于中渗带时,能够一定程度上提高采出程度,虽然提高了中渗带剩余油的动用程度,但大部分低渗带的剩余油仍然没有动用。当水平井同时位于中、低渗带时,提高采出程度的幅度小于低渗带为水平井的方案,而大于中渗带为水平井的方案。

The effect of different well types of inverted nine spot pattern on the oil displacement efficiency of polymer flooding in Offshore Oilfield

In this paper, we conduct the physical simulation experiment by using a three-dimensional planar homogeneous core model with a micro electrode and compare the effect of vertical well and horizontal well on exploitation effect and remaining oil distribution under the condition of inverted nine-spot pattern. In the condition of homogeneous inverted nine spot pattern (consisting of 1 injection and 3 production wells). One of the wells is horizontal well. Drainage area controlled by the horizontal well is large. In the drainage area, producing degree of remaining oil in vertical well is less than that in horizontal well. Recovery of horizontal well (single well) is 2.53% more than that in vertical well (single well) in the same location. But the overall improvement in the development of the effect is not obvious. For further research of the effect of different well types on exploitation effect and remaining oil distribution, we conduct the numerical simulation of the effect of different horizontal well types on exploitation effect in heterogeneous condition. The results show that the effect of the combination of vertical well and horizontal well in heterogeneous model is better than using vertical well respectively. Recovery and remaining oil range of different horizontal well location have some differences. When the horizontal well located in low permeability area, the remaining oil after conducting vertical well experiment is produced largely. The saturation of remaining oil is lower. The recovery is higher than the past. When the horizontal well located in the middle permeability area, it improves the recovery to a certain extent. Though the producing degree in middle permeability area is higher, most of the remaining oil in low permeability area is not produced. When the horizontal well located in the low and middle permeability area, the recovery is higher than that in low permeability area and lower than that in the middle permeability area.