中文摘要：

文88区块的储层物性为低孔低渗，平均孔隙度为13．9％，平均渗透率为7．4mD，储层温度为145℃，原始地层压力64．98MPa，压力系数1．7-1．8，属异常高温高压油藏，衰竭采收率较低，且注水效果差。为了研究该油藏注气提高采收率可行性，在室内进行了注气膨胀和长岩芯驱替实验，得到了注天然气改善原油物性的效果以及不同注气方案下的驱油效率，研究结果表明：注天然气能明显改善原油的物性，对原油的降黏效果和膨胀效果较明显；两种注气方案中，原始地层条件下注气的驱油效率较好，达到82．97％，目前地层条件下注气在一定程度上提高了驱油效率。

英文摘要：

The physical property of Wen 88 Block is low porosity and low permeability with the average porosity at 13.9%, and the average permeability at 7.4 mD, and its initial formation pressure and temperature is 64.98 MPa and 145 ℃, respectively, and the pressure coefficient is 1.7-1.8, so it belongs to abnormal high temperature and high pressure reservoir whose depleted recovery efficiency is quite low and water injection response is also poor. In order to study the feasibility of reservoir gas injection, we have carded out gas expansion experiments and long core tests which proved that gas injection can improve the physical property of crude oil and got displacement efficiency for different gas injection plan. The results of these experiments show that gas injection can significantly improve physical property of crude oil and have apparent effects on lowering viscosity and expanding of crude oil. Moreover, the sweep efficiency under the original formation conditions is much better than that under the present formation conditions. However, the latter can also boost sweep efficiency to a certain extent.