超低渗油藏氮气泡沫驱合理交替周期研究

Study on reasonable alternate cycle of nitrogen foam flooding in ultra-low permeability reservoir

通过开展岩心驱替实验,对超低渗油藏氮气泡沫驱合理气液比和段塞尺寸进行了优选研究,以确定合理交替周期。结果表明,气液比1∶5和5∶1时提采幅度最高,在现场应用中,根据流体资源情况,可以选择注入较长的水段塞、较短的注气段塞或者较长的注气段塞、较短的注液段塞;优选了最佳段塞尺寸为0.2 PV,即井间注入量达到1PV时的合理交替周期数为5个。

In this paper,through core displacement experiments,optimization research is carried out on the reasonable gas-liquid ratio and slug size of nitrogen foam flooding in ultra-low permeability reservoir,so as to determine the reasonable alternate cycle.The results show that the extraction amplitude is the highest when the gasliquid ratio is 1:5 and 5:1.In field application,according to the situation of fluid resources,you can choose to inject a long water slug or a short gas injection slug or a long gas injection slug or a short liquid injection slug.The optimal slug size is 0.2PV,that is,the reasonable number of alternate cycles is 5 when the injection volume between Wells reaches 1PV.