Fig.3: Recovery factor and water cut of No.1 core sample flooding with biological enzyme concentration of 5‰ Fig.3 Fig.4: Recovery factor and water cut of No.2 core sample flooding with biological enzyme concentration of 2% Fig.4 Fig.5: Recovery factor and water of No.3 core sample flooding with biological enzyme concentration of 5% Fig.5 Fig.6: Relationship between concentration of biological enzyme and extent of plug removal (EPR) Fig.6 Limestore / Sandstone at 1) 0 ; 2) 5 minutes; 3) 5 hours Fig.2: Wettability changes with time for Limestone and Sandstone Table.8: Results of well treatments of Y8 reservoir New Agent for Formation-Damage Mitigation in Heavy-Oil Reservoir: Mechanism and Application Y. Wang and A. Kantzas, SPE, University of Calgary; B. Li and Z. Li, China University of Petroleum (East China); and Q. Wang and M. Zhao, Dongxin Oil Company, Shengli Oil Branch, SINOPEC, P.R.China SPE 112355 Español SPE 112355 Ingles