Factors influencing the profile control performance of starch gel

Bohai Oilfield has been developed for over 20 years and its reservoir heterogeneity is serious.And if the single-well injection/production intensity is increased, the heterogeneity will get worse further.The reservoirs and fluids in SZ36-1 Oilfield of Bohai Sea were selected especially as the simulation objects so as to solve the problem of reservoir heterogeneity.The range of starch gel system was determined by means of lab experiment.Then, laboratory core displacement experiment was carried out on the profile control system whose concentration was different.Finally, the profile control system was optimized with injection pressure, water cut and recovery factor increase as the evaluation factors.And the optimized formula is 4% modified starch+4% acrylamide +0.036% crosslinker+0.012% initiator +0.002% anhydrous sodium sulfate.By virtue of this profile control system, reservoir heterogeneity is alleviated and the recovery factor is enhanced significantly, 22.1% higher than the water flooding result.