超稠油油藏注氮气辅助蒸汽吞吐数模研究

超稠油油藏蒸汽吞吐后期,油汽比低,周期含水量高,开采效果差,注氮气辅助蒸汽吞吐已经成为1种提高超稠油开采效果的有效手段。与常规稠油油藏不同,超稠油对于注氮参数以及筛选条件有更严格的限制。模拟研究得知,超稠油油藏蒸汽吞吐不同时期宜采用不同的注氮模式。因该类型油藏对原油黏度、油层厚度、采出程度敏感性较强,从而确定超稠油油藏选井标准。该研究对同类油藏注氮辅助蒸汽吞吐开采具有指导意义。

Numerical simulation of nitrogen assisted cyclic steam stimulation for super heavy oil reservoirs

In the late life of cyclic steam stimulation for super heavy oil reservoirs,oil-steam ratio is low,water cut is high,and recovery effect becomes poor.Nitrogen assisted cyclic steam stimulation has become an effective way to improve super heavy oil recovery.Different from conventional heavy oil reservoirs,super heavy oil reservoirs are more stringent in regards to nitrogen injection parameters and screening conditions.Numerical simulation shows that different nitrogen injection measures should be adopted at different stages of cyclic steam stimulation.Super heavy oil reservoirs are more sensitive to oil viscosity,reservoir thickness and recovery percent,thereby well screening criteria can be determined for super heavy oil reservoirs.This study has guiding significance to nitrogen assisted cyclic steam stimulation in similar reservoirs.