Abstract: The lab test of hydrocarbon gas injection into low permeability and volatile reservoir in Block Wen-72 of W enliu oilfield is presented, which includes physical property study of formation fluid, injected solvent component analysis and the minimum miscibility pressure of formation fluid and injected solvent at 130C through slim tube. The study shows that the minimum miscibility pressure is 47.1Mpa, the recovery factor is 65.7% when gas breakthrough is made, the ultimate recovery factor is 86. 1%. Water flooding lab test indicates that the breakthrough recovery is up to 61.9%,the recovery factor is up to 64.5% when water cut is up to 98%. Gas/ water alternating injection following water flooding includes 3 cycles for each plug of 0.2PV. The ultimate recovery factor of 95.22% is higher than that of water flooding by 30.69%.

Key words: Wenliu oilfield, low permeability reservoir, gas drive, laboratory testing, recovery factor