纵向渗透率级差对注水井吸水特征的影响

Effects of vertical permeability contrast on water absorption in water injection well

在考虑启动压力梯度的基础上,建立了注水井纵向非均质储层的吸水量之比关系式,分析了非均质程度、注采压差、低渗层流度和注采井距对高、低渗层吸水能力的影响。研究结果表明:非均质程度越大,高、低渗层吸水能力差别越大;注采压差越大,高、低渗层吸水能力差别越小;低渗层流度越大,高、低渗层吸水能力差别越小;注采井距越大,高、低渗层吸水能力差别越大。通过实验验证,该关系式计算的高、低渗储层吸水量之比与实验结果非常接近,能很好地预测纵向非均质储层注水各层吸水能力,为研究类似储层吸水特征提供了理论依据。

Considering the threshold pressure gradient, a water absorption formula in water injection well in vertical heterogeneous reservoir is established. The affecting factors of water absorption in layers are analyzed, such as degree of heterogeneity, injectionproduction pressure difference, mobility of low permeability layer, injector-producer distance. The results show that the change trends of absorption capacity difference between high and low permeability layers are similar to degree of heterogeneity and injector producer distance, but are opposite to injection-production pressure difference and mobility of low permeability layer. Experiments show that the ratio of absorption calculated by this formula is very close to that of experimental result. This forrmula can provide a theoretical basis to predict the water absorption capacity of layers in vertical heterogeneous reservoir.