New progress of petroleum resources survey in South Yellow Sea basin

The South Yellow Sea basin is a large-scale sedimentary basin composed of a Paleo-Mesozoic marine sedimentary basin superimposed by a Meso-Cenozoic continental sedimentary basin. Petroleum geological survey and exploration started there in the early 60s of the last century, and up to date has passed through three stages, i.e. the stage of investigation and exploration of terrestrial basin, the stage of summarization and scientific research, and the stage of investigation and exploration of the marine basin. For more than 50 years, commercial petroleum discoveries have not yet been gained because of ceomplex geological conditions, complicated history of basin evolution and geological structures, and relatively low exploration levels. After a long-term research on seismic exploration technnology since 2005, we have preliminary developed a method called "high, rich, strong" in abbreviation for seismic exploration technology for the deep basin, which is a combination of acquisition technology with "high coverage, rich low-frequency signals, and strong source energy" and processing technology of "high-resolution, low-frequency, high-reflection-energy". With the method, we have obtained effective seismic reflections from deep marine layers. Further investigation and studies in recent years have led to following conclusions. 1. The South Yellow Sea Basin is not only an extension of the Yangtze Plate into the sea, but also the main body of the Lower Yangtze Block; 2. The South Yellow Sea Basin and the Sichuan Basin aresimilarin sedimentary sequences and evolutionary history during the period while the marine Meso-Paleozoic was deposited; 3. In the thick marine Meso-Paleozoic deposits below the continental facies of Meso-Cenozoic strata, there are three sets of seismic reflection markers traceable in the region, upon which the seismic sequence stratigraphy of the Meso-Paleozoic marine sediments is established; 4. There are three sets of high-quality source rocks and three sets of source-reservoir-cap assemplages in the basin, including the Hetang Formation (or Mufushan Formation) of Lower Cambrian, the Wufeng Formation of Upper Ordovician plus Gaojiabian Formation of Lower Silurian, and the Longtan and Dalong Formations of Upper Permian, which founded the material basis for formation of large-scale oil and gas fields; 5. Theoretical simulations and inclusion analysis indicate that there aremulti-source and multi-stagepetrolem accumulation in the marine Meso-Paleozoic basin; 6. The Laoshan uplift is a Early Paleozoic marine facies petroleum prospect and the Wunansha uplift is a marine facies of petroleum prospect of Late Paleozoic; 7. The Gaoshi stability zone of the Laoshan uplift is a favorable exploration target, and there are possiblities to find the "Weiyuan type" and "Anyue type" oil and gas fields discovered in the Sichuan Basin; 8. Gaoshi 3 structure is the preferred drilling target in the Paleozoic. Efforts should be devoted tothe implementation of the planned parameter well with the lower Paleozoic as the main target layers, the establishment of a complete Meso-Paleozoic stratigraphic sequence in the region, and the collection of resource assessment parameters. A breakthrough in strategic discovery and exploration of the petroleum survey is expectable at the South Yellow Sea.