Experimental study on the effect of profile modification and its influencing factors in LD10-1 Oilfield

LD10-1 Oilfield is characterized by high temperature, high salinity, high viscosity of crude oil, and serious heterogeneity. Due to the poor water flooding effect, it is necessary to apply new methads to enhance oil recovery. A series of experiments were conducted to investigate the viscosity, molecular structure, molecular coil dimensions, flow characteristics, and oil displacement effect of the salt resisting solution and Cr³⁺/HPAM (high molecular) gelant. Meanwhile, the effect of profile modification is analyzed and mechanism of the reagents is proposed. The results indicated that intra-molecular structure gelant can be formed, which was prepared by LD10-1 injection water. The hydraulic diameter (D_h) of the gelant did not increase significantly, but the resistance factor and residual resistance factor increased. The residual resistance factor was larger than the resistance factor, presenting a specific flow characteristics compared with HPAM solution prepared by the same polymer concentration. At the same cost and injection opportunity, the profile modification effect of gelant was better than that of salt resisting solution. The larger injected pore volume of fluid and earlier injection opportunity resulted in a better EOR.