Abstract: Hainan-3 fault block in Liaohe Tanhai oilfield is a layered lithologic-structural reservoir with edge water. Following 10-year waterflood development, the inconsistency of development is more and more emerging. In despite of conducting a series of producer water plugging and injector adjustment and obtaining some responses, the year-by-year water cut increasing has caused it to become poor in water drive effectiveness. Searching for new water flood mode to improve the water drive response becomes a necessary task. This paper selects favorable test area based on the geologic feature of Tanhai oilfield for first feasibility evaluation of its cyclic water flood, parameter estimation and field test. The good results for increasing production and improving displacement response provide foundation for implementation of next large-scale cyclic water flooding in this field.

Key words: Tanhai oilfield, water wet, middle-low permeability, heterogeneity, cyclic water flood, feasibility analysis, parameter estimation