Physical Simulation of Oil and Natural Gas Secondary Migration

In this paper,we simulate oil and natural gas secondary migration process by injecting oil and natural gas into straight glass tube model saturated water and filling glass beads from bottom in top.The results show that there are two migration stages of piston-type and advantage-type during oil secondary migration process and natural gas secondary migration has the piston and advantages basic migration styles.We discuss the differences of oil and natural gas secondary migration process based on physical and chemical properties of oil,gas and water.The property of oil and gas itself cause the differences of secondary migration process.In the secondary migration process,oil can replace free water in rock pores and adsorbed water on rock surface,forming the stability with pore rock.So,the oil secondary migration phase is obvious.Natural gas secondary migration is much active owing to strong buoyancy difference between natural gas and formation water density.Thus,the natural gas secondary migration is an intermittent migration which is markedly different from oil secondary migration.