The field test about CO_2 in low permeability oilfield of Daqing outskirt

摘要

Note CO_2 gas development has become a very effective reservoir mining method in low permeability oilfield of Daqing outskirt. It can effective enhance the recovery ratio. When the crude oil dissolves CO2, the volume expands and the viscosity decreases. Under the same conditions of temperature, expansion increases with pressure, CO_2 drive is more effective than a single water drive, the degree of reserve recovery has been significantly improved, generally 1.3-1.4 times. Field tests shows that the input-output ratio in swallowing- spitting test of CO_2 producing in formation could reach 6.25.