高含水期二氧化碳驱油室内探索

Indoor carbon dioxide flooding explorations at the high water-cut stage

对低渗油田高含水地层条件下二氧化碳驱油进行了室内模拟实验,实验发现,当水驱到未完全水淹时,转注气驱提高采收率是可行的。注气方式以分段多次注入效果较好。当水驱至含水率为90%转气驱,驱替压力为25 MPa时,平均采收率比持续水驱可再提高29.32%。若水驱至含水率为90%转为水气交替驱,最终采收率比持续水驱高出33.72%。

The indoor carbon dioxide flooding simulation experiment was made at the low permeability oil fields under the geological conditions of high water cut. Experiment found that when stratum wash＇ t com- pletely flooded, gas flooding to improve oil recovery is possible, the segment multiple injection effect is better. When moisture content is 90% turn to gas drive, the recovery efficiency can be increased by 29.32% on average than continuous water flooding at the displacement pressure of 25 MPa. If water flood- ing to the moisture content of 90% then turn to water and gas alternating flooding, the ultimate recovery efficiency can be increased by 33.72% than continuous wma~ d^i,,,~