Evaluation Of C10 Reservoir Water Flooding

Ansai oilfield C10 reservoir is a typical "Three Lows" reservoir, without obvious bottom water and edge water. It has been conducted large-scale waterflood development for two years to improve the effect of block development. So it is necessary to evaluate the effect and study the law of waterflood development. It provides the basis for the further reasonable and effective development policy.This paper analyzes the characteristics of the reservoir bed firstly; Secondly, a single well production capacity and production decline rule is analyzed by using the application of dynamic data analysis;Thirdly, the water change rule of north and south block is analyzed; The effect of waterflood is analyzed; Waterflood reserves is also calculated.The adaptability of the flooding pattern is evaluated. The reasonable injection pressure is calculated, and the ultimate oil recovery is predicted; The reasonable production rate, IWR and the water injection ratio is determined by using a variety of methods; the current effect of water injection is evaluation comprehensively.Research shows that the C10 reservoir bed is the grain sandstone reservoirs,and the reservoir heterogeneity of Layer and plane is Slightly strong; Because of the differences of physical properties, single well production of the north block in study area is better than the south, the well density of north is relatively small and can be encrypted according to the actual situation in the follow-up the development process,and the South well density is more appropriate.The water change rule of the north block can be described by WanShi multi-gas series of concave-S type formula, and it can be described by sunken model formula in the south block; NE-SW direction is the main direction of Northern water effective, North-south direction is the main direction of the Southern water effective; The main effective direction and the direction of sand is in the same direction; Waterflood reserves in the North, the water use efficiency and ultimate recovery is all higher than the South block.Now, the oil production speed is fast,and the actual injection-production is larger than theory injection-production ratio in the study area.