特低渗透油藏水驱矢量化井网影响因素分析

Analysis on Influencing Factors of Water-drive Vector Well Pattern in Ultra-low Permeability Reservoirs

众多学者提出了矢量开发思想,但对于其影响因素的研究较少,制约了矢量化井网在矿场中的应用效果。依据矢量化井网思想,以实际工区典型井组为原型,建立井组概念模型。结合已有文献的物理模拟实验结果,利用油藏数值模拟技术,对典型井组概念模型均衡见水时间的多个影响因素进行了分析论证。结果表明:在均衡驱替且油井见水时间基本一致的前提下,主渗透率方向两侧油井之间的排距随着方向渗透率比Ky·Kx-1的增加逐渐加宽,特别对于角井,变化最为显著;随Ky·Kx^(-1)增加,注入水波及范围逐次扩大,Ky·Kx^(-1)=1.0时侧向波及效率明显优于Ky·Kx^(-1)=0.2;高产量比时,虽然井组总产量较高,但单井产量递减速度明显大于低产量比模型,但低产量比时也存在波及系数较低的缺陷。实例验证结果进一步表明,矢量化井网影响因素的研究结果对于现场井网调整有切实的指导作用。

Many scholars have put forward the idea of vector development, but there are few studies on its influencing factors, which restrict the application effect of vector pattern in the field. In this paper, based on the idea of vectoring well pattern, the conceptual model of well group was established based on the prototype of typical well group in actual work area. Based on the experimental results of physical simulation in the existing literature, the influence factors of the equilibrium water breakthrough time in the conceptual model of typical well group were analyzed and demonstrated by using the reservoir numerical simulation technology. The results showed that, on the premise of balanced displacement and basically the same water breakthrough time of the well, the row spacing between the two sides of the wells in the direction of the main permeability gradually widened with the increase of the directional permeability ratio Ky·Kx^(-1), especially for the angle wells.When Ky·Kx^(-1)=1.0, the lateral sweep efficiency was significantly better than that of Ky·Kx^(-1)=0.2.In the case of high yield ratio, although the total output of the well group was higher, the decline rate of single well production was obviously higher than that of the model of low yield ratio, but there was also the defect of low sweep coefficient in the case of low yield ratio. The results of the study on the influencing factors of vector well pattern have practical guiding effect on the adjustment of field well pattern.