Abstract The low concentration flowing gel (LCFG) fluid diversion technique is a promising IOR method developed in recent years. The displacement mechanism of the weak gel, the physico-chemical properties and other influencing factors, specifically the gel formation, the physical characteristics, the mobility in porous media and the adjustment of permeability, etc., were studied in detail in this paper. A numerical simulator was accordingly established and used initially to simulate laboratory LDFG displacements with satisfactory results observed. A pilot test of the weak gel fluid diversion was consequently simulated and designed using the simulator. The scenario was optimized and economic evaluation was carried out. The pilot test has been put into implement and the performance was in agreement with the prediction.