海上普通稠油油藏多层合采层间干扰定量表征与定向井产能预测

Quantitative characterization of interlayer interference and productivity prediction of directional wells in the multilayer commingled production of ordinary offshore heavy oil reservoirs

采用可视化的多管水驱油物理模拟实验,结合实际油田生产资料,定量表征海上普通稠油油藏多层合采过程中的层间干扰现象,并建立适用于普通稠油油藏多层合采的定向井产能预测方法。建立了普通稠油油藏多层合采过程中采液指数和采油指数的干扰系数动态表征关系式;引入干扰系数,并考虑启动压力梯度的存在,修正Vandervlis定向井产能公式,得到适用于普通稠油油藏定向井多层合采的产能动态预测公式。储集层纵向渗透率的差异是层间干扰最主要的影响因素,可用储集层基准渗透率、渗透率级差和渗透率偏差综合描述。多层合采过程中,层间干扰对不同含水阶段油井产能的影响程度不同,中高含水期层间干扰对整体产油能力的抑制作用加剧,需要采取相应的调整措施;考虑层间干扰后产能预测精度明显提高,修正后的定向井产能公式可以较好地应用于现场生产。

Based on the physical experiment of visible multi-tube water flooding, in combination with field production data, the interlayer interference in multilayer commingled production of ordinary offshore heavy oil reservoirs is quantitatively characterized and an appropriate productivity prediction method of directional wells is established for multilayer commingled production of ordinary heavy oil reservoirs. The interference coefficient formulae of fluid and oil production indexes are obtained for the multilayer commingled production of ordinary heavy oil reservoirs. The Vandervlis directional well productivity equation is revised by introducing interference coefficient with consideration of starting pressure gradient and a dynamic productivity prediction equation is finally established suitable for multilayer commingled production of ordinary heavy oil reservoirs. Interlayer interference is mainly controlled by vertical reservoir permeability difference, which can be comprehensively characterized by reservoir reference permeability, permeability contrast and permeability deviation. The productivity of wells with different water-cut stages is variously affected by interlayer interference. This influence will be intensified in high water-cut situation, which needs appropriate adjustment measures. The productivity can be more accurately predicted by considering interlayer interference, and the revised directional well deliverability equation can be well applied to field production.