In the later stages of M oilfield development, production declines sharply, with significant differences in the utilization of thin and thick layers. Inefficient and ineffective cycles in thick layers are particularly severe. It is crucial to advance precision development to further control the decline of mature oilfields. This study based on detailed reservoir characterization and focusing on Single Sand Bodies as the key adjustment object, treats the precise water injection of Single Sand Bodies as a systematic engineering project. The study aims to achieve the “Four Precisions”—accurate sand body characterization, precise stratified water allocation, accurate process testing, and precise potential analysis. By shifting paradigms and breaking traditional boundaries, the study innovatively develops and continuously refines relevant technologies for precision development. This approach improves the reservoir production, strives to push precise water injection to its limits, and meets the needs of mature oilfields in the high-water-cut development stage. The findings of this research have significant practical implications for improving development efficiency in the later stages of oilfield exploitation, offering valuable references for enhancing reservoir development efficiency and supporting sustainable development [1–25].