Characteristics of Hydrocarbon Migration and Accumulation and Their Petroleum Geological Significance on the Northern Slope of Lingshui Depression, Qiongdongnan Basin

The deep‐water area of the south slope of the Lingshui Depression in the Qiongdongnan Basin has already yielded the Deep Sea No. 1 gas field. However, so far, there have been no significant breakthroughs in exploration in the shallow‐water area of the north slope. Indeed, there has been no systematic analysis of hydrocarbon migration and accumulation in this area from the perspective of fluid potential, which has limited the understanding of accumulation characteristics and restricted the selection of preferred exploration targets. This study utilizes the latest drilling, logging, and 3D seismic data, combined with the Hubbert fluid potential model, to quantitatively reconstruct the paleoburial depth and fluid potential fields during critical phases of the accumulation history. It sets out a hydrocarbon‐accumulation model grounded in the “hydrocarbon migration compartment” energy theory and constrained by geological conditions. The oil and gas migration and accumulation units on the northern slope of the Lingshui Depression are precisely delineated, and the accumulation model shows that, during the Late Miocene, both the north and south sides of the northern slope of the Lingshui Depression were high‐potential zones, and the middle part was a low‐potential zone, with the distribution showing a gradual decrease from the north and south sides to the low high in the middle. The central migration and accumulation unit is the most promising exploration target on the northern slope of the Lingshui Depression, with hydrocarbons supplied from two sources, three‐dimensional migration, and late accumulation, which is the main potential area for future exploration. The results are of great significance for determining the next step for oil and gas exploration in the study area.