Abstract: The south oil region of Dagang oil field is characterized by complicated fault block, multilayer system and heavy oil reservoirs. The size of the fault block reservoir is small with serious areal heterogeneity, interlamination heterogeneity and intralamination heterogeneity. Most of these reservoirs are in the high water cut stage and the waterflood feefct is becoming worse and worse, the artificial earthquake technology is applied to produce ultrasonic that it can decrease crude oil viscosity and improve the crude oil flow ability. The technology used in the Wangguantun and Zaoyuan oil field acquired the marked effectiveness, which improves the waterflood eefect in the high water cut stage, and slow down the ascending water containing speed. By the six times experimentation with four wells , the summation of crude output is 8499t and the input/output ratio is 1∶9.3. The downhole artificial earthquake oil flooding technology supplies a kind of new technology for the complicated fault block, heavy oil reservoirs and high water cut reservoir development. The technology has many advantages, such as wide operation area,  small degree of damage to reservoir and the low input/output ratio. The artificial earthquake oil flooding technology has a good future for oil production.

Key words: complicated fault block, multilayer system, heavy oil reservoirs, downhole artificial earthquake, oil flooding