In recent years, with the intensification of development conflicts during the high water cut period in the old areas of Daqing Oilfield, secondary development of old oilfields has gradually become a focus of attention in oilfield development. This study focuses on the water drive fault block area in the South Sixi area of the Sanan oil field, and completes research on fine reservoir description, prediction of remaining oil distribution, and optimization of injection production structure adjustment. Firstly, based on the theory of segmented fault growth and the combination of well seismic techniques, the structure of the fault block area is further understood. This study will divide the study into three closed zones. Based on the detailed description of sedimentary facies, in response to the geological and production characteristics of each enclosed area, personalized comprehensive tapping of potential is implemented by supplementing drilling to improve injection and production, subdividing layer series development, reducing injection and production well spacing in thin and poor oil layers, strengthening residual oil analysis, and enhancing water drive well network restoration development. At the same time, in order to deeply tap the remaining oil at the edge of the major fault, supporting measures such as high inclination wells were explored to tap the potential, and the injection production structure adjustment technology was improved. Through new fracturing techniques such as reverse pressure drive, various oil layers in the three enclosed areas were balanced and utilized. The comprehensive potential tapping technology studied in this article has achieved significant results in the fault block area of Sanan Oilfield. The production capacity and recovery rate of the oilfield have been effectively improved, and production costs have been effectively controlled, laying a solid foundation for the sustainable development of the oilfield and providing useful reference and inspiration for the potential tapping work of similar oilfields.