Sandstone oil fields have entered the late stage of high water cut development, and there are generally problems such as difficulty in improving recovery rates and decreasing development benefits. The distribution pattern of remaining oil is complex, and conventional tapping measures are ineffective, posing challenges to improving recovery rates. This article takes the Gao 30 fault block in Huabei Oilfield as an example, analyzes the geological characteristics and development status of the block, and combines logging interpretation, liquid production profile, and water absorption profile to explore the influence of reservoir properties, structural characteristics, and injection production well network completeness on the distribution of remaining oil. The research results indicate that the comprehensive water content of the block currently reaches 88.5%, with a recovery rate of 19.3%. The remaining oil is mainly enriched in the root of faults, areas with incomplete well networks, and weak water drive surfaces, and vertically concentrated in the 2nd and 3rd sub layers of the Es ₂ section. A systematic tapping plan of "horizontal well + injection production well network adjustment + profile control" has been proposed for different types of remaining oil. The implementation of horizontal well technology can excavate the remaining oil at the root of faults, optimize the injection production well network can improve water drive efficiency, and profile control can improve interlayer contradictions. This study provides new technical ideas and practical experience for the efficient development of remaining oil in high water cut fault zones.