Abstract: The suction role of seismic pumping can induce fluid flowing into fault zone and further migrating into the fault zone. When micro-fractures develop and become dominant fractures, further form fault, the suction role of seismic pumping occurs. At the same time, fluid inside surrounding rock flows into fault zone as a result of relative negative pressure suction role. Afterward, fluid migrates upwards along fault zone as a result of tectonic stress and abnormal pore pressure, and flows into a reservoir with bad sealing, large volume and good physical property, where migrating efficiency is much higher than that of Darcy flow and diffusion flow. Because of periodically faulting hydrocarbon pumping migration along fault zone is periodic, intermittent and pulsant, and hydrocarbon migration and accumulation often locates the newest strata. The physical simulation results on the process of gas migration and accumulation in Kela 2 gas-field indicate that the fault below salt near trap is effective migrating passage of natural gas, whereas the fault cutting salt is noneffective migrating passage of natural gas. It also indicates that the natural gas migration along fault zone is characterized by high speed and high efficiency under the suction role of seismic pumping, and natural gas can migration and accumulation at large scale in the short time of faulting.

Key words: seismic pumping, suction role, hydrocarbon, migration and accumulation, fault, physical simulation