Experimental study on vertical light hydrocarbon microseepage mechanisms

Understanding hydrocarbon microseepage mechanism is important for interpreting hydrocarbon anomalies in the surface geochemical exploration. An experiment was developed to simulate the vertical microseepage of hydrocarbons with multiple lithological layers. The results revealed that the microseepage below the water table was dominated by buoyancy of microbubbles with diffusion as a secondary mechanism, however, it was dominated by diffusion with little effect by gas convection above the water table. The micro-fractures were the dominant channels for microseepage. A phenomenological model was developed to quantify the vertical microseepage in different media and provided a better tool in a field environment.

Automated summary

Understanding the mechanism of hydrocarbon microseepage is crucial for interpreting hydrocarbon anomalies in surface geochemical exploration. An experiment was conducted to simulate vertical microseepage with multiple lithological layers, revealing that microseepage below the water table is primarily controlled by the buoyancy of microbubbles with diffusion as a secondary mechanism, while the dominance of diffusion and minimal gas convection effect is observed above the water table. Micro-fractures were identified as the main channels for microseepage. A phenomenological model was developed to quantify vertical microseepage in different media, providing a valuable tool for field applications.