Abstract: Oil and gas are generated from organic matters in the rocks of sedimentary basins. Through an intensive and systematic study of global petroliferous basins, it is recognized that the distribution of global oil and gas fields is highly uneven, and most of oil and gas are enriched and accumulated in a few strata of sedimentary rocks. The distribution of oil and gas is significantly controlled by source rock, so that it is necessary to search for the source rocks initially before discovering new petroliferous basins. The nutrients required for biological growth in the sedimentary basins primarily come from rivers, and the nutrients flowing from rivers into the sedimentary basins control the degree of biological reproduction, and then control the abundance of organic matters in the source rocks, which decides the amount of oil and gas generated and the degree of enrichment of oil and gas resources in the sedimentary basins. Oil and gas are mainly distributed in the three systems on the earth, i.e., the river-lake system, river-gulf system and river-delta system. Specifically, the river-lake system is an important oil-bearing area on the earth. Lacustrine oil is mainly produced by sedimentary organic matters from the algae died in lakes. The growth of algae depends mainly on the nutrients that come from the rivers and flow into the lakes, and these nutrients can facilitate the growth of algae in the rift period and provide a guarantee for the formation of high-quality source rocks. The river-gulf system is the main distribution location of global marine oil. Gulfs are the estuary of rivers, which brings abundant minerals for rivers to promote the growth and proliferation of algae and other aquatic organisms; moreover, the gulfs are relatively isolated, which are conducive to the preservation of organic matters. In fact, boasting of the biggest reserves, the coal-type gas generated from coal-measure source rocks is the most widely distributed in the world and is mainly distributed in the river-delta system. The sediments brought by the river provide fertile soil for the growth of higher plants, and the native higher plants on the river-delta plain provide a solid material basis for the formation of coal-measure gas source rocks. The delta stratum reservoir is well developed with good reservoir-caprock configuration, which is beneficial for natural gas enrichment and accumulation.

Key words: source rocks, sedimentary basins, oil, natural gas, river-lake system, river-gulf system, river-delta system

摘要： 油气是由沉积盆地内岩石中的有机质生成的。通过对全球含油气盆地进行深入、系统研究，认识到全球油气田的分布很不均匀，油气只在少数沉积岩层段内富集成藏。油气分布具有明显的"源控"性，寻找新的含油气盆地必须首先寻找烃源岩。沉积盆地内生物生长所需的营养物质主要来源于河流，河流注入沉积盆地的营养物质控制了生物繁衍程度，进而控制了烃源岩的有机质丰度，而烃源岩有机质丰度控制了沉积盆地的油气生成量和油气资源富集程度。地球上油气主要分布于河流—湖泊体系、河流—海湾体系和河流—三角洲体系，其中，河流—湖泊体系是地球上重要的含油领域。湖相石油主要是由湖泊中的藻类死亡后形成的沉积有机质生成，藻类生长主要取决于河流注入湖水中的营养物质，这些营养物质可以促进裂谷期藻类生长，为优质烃源岩的形成提供保障。河流—海湾体系是全球海相石油分布的主要场所。海湾是河流的入海口，河流带来丰富的矿物质促进了藻类等水生生物生长并大量繁殖，且海湾相对闭塞，均有利于有机质保存。世界上分布最广、储量最多的天然气是由煤系烃源岩生成的煤型气，河流—三角洲体系是煤型气的主要分布场所。河流带来的泥沙是高等植物生长的肥沃土壤，河流—三角洲平原上的原生高等植物为煤系气源岩的形成提供了雄厚的物质基础；三角洲储层发育，储-盖配置好，有利于天然气富集成藏。

关键词: 烃源岩, 沉积盆地, 石油, 天然气, 河流—湖泊体系, 河流—海湾体系, 河流—三角洲体系