Formation of Oil and Gas Surface Anomaly and its Evaluation

While oil and gas from a deep reservior migrates near surface along the micro fracture of sedimentary rocks covering above the reservior, the original geochemical characteristics of soil are changed. Thus, the recognizable geochemical anomaly is formed in the near surface soil. After analyzing soil hydrocarbons, soil secondary carbonate (△C), soil mercury and the carbon isotope of methane and △C, and so on, we may supply an important information on determinating oil - gas migration, discovering geochemical anomaly related to deep oil and gas reserviors, and, thereby, may suggest the existence of deep oil and gas in buried reserviors.According to our study on the geochemistry of soil hydrocarbons, soil secondary carbonate and soil mercury, different geochemical indicators and methods are of different results in various geochemical landscapes.