针对流管法无法应用于超低渗油藏井网调整后的平面波及系数计算问题,在考虑超低渗油藏渗流特征的基础上,结合BL方程,通过引入虚拟流量,使用坐标变换,将井网调整前的流管数据转化到井网调整后的新流管数据中,建立了考虑井网调整的新流管模型,实现了超低渗油藏注水开发全周期的平面波及系数快速评价。利用建立的新流管模型,探究了影响超低渗油藏井网调整面积波及系数的主控因素,厘清了超低渗油藏井网调整的技术界限,现场应用取得了良好的增产效果。当井距＞200 m、各向异性系数＜5时,井网调整可以取得较好的效果;启动压力梯度越大,井网调整效果越好。典型井组井网调整后5 a产能提升了47.6%。超低渗透油藏面积波及系数计算新方法对超低渗透油藏开发效果评价具有一定指导意义,同时对同类油藏的开发调整具有一定的理论指导价值。

In ultra-low permeability reservoirs, the flow tube method is inadequate for calculating plane sweep efficiency following well pattern adjustments. This study introduces a novel flow tube model tailored for these reservoirs. By integrating the B-L equations with a method that transitions properties from the old flow tube to new ones post-adjustment, using virtual flow and coordinate transformation, this model facilitates swift evaluations of plane sweep efficiency throughout the waterflooding development phase. Utilizing this innovative model, we examined the primary factors influencing the plane sweep coefficient after well pattern adjustments in ultra-low permeability reservoirs and pinpointed the technological constraints of such adjustments. This model has proven effective in field applications. Our findings indicate that optimal results are achieved when well spacing exceeds 200 m, and the anisotropy coefficient is below 5. Furthermore, a larger starting pressure gradient enhances the outcomes of well pattern adjustments. Notably, a typical well group’s productivity surged by 47.6% within five years post-adjustment. This novel approach to calculating the area sweep coefficient for ultra-low permeability reservoirs offers valuable insights for assessing the development of the Ordos Basin‘s ultra-low permeability reservoirs. Additionally, it provides theoretical guidance for adjustments in similar reservoirs.