Abstract: The Shusan block of Shuguang Oilfield is an unconsolidated sandstone reservoir with a burial depth of 950 m and a shale content of 13.9%. Affected by this, the compaction of the reservoir is poor and the cementation of the reservoir is loose. The sand production of oil wells in the reservoir is serious, with poor development effects, and the predicted recovery rate is only 30.8%. The unconsolidated sandstone reservoir in Shu 3 block has entered into themiddle and later development stages, which has encountered a series of problems such as rapid water rise and poor development effects. After carrying out the research on chemical flooding related to reservoir engineering, the results show that the optimized formula system for chemical flooding and the ancillary sand control technologies can effectively improve oil recovery. Applying the research results to 6 well groups, after the pilot test of chemical flooding, the daily oil production was significantly increased, and the comprehensive water cut decreased by 14.2 percentage points, which effectively improved the development effect. The research provides a reference for the chemical flooding development of similar reservoirs.

Key words: unconsolidated sandstone, flooding mode conversion, chemical flooding, Shu 3 block, pilot test, thin oil, polymer