Improved For Determining Fault Block Oil Reservoir Development Effect Of Injection-production Optimization Study Way

Shengli Oilfield has totally proved59block reservoirs with794units in all, and their15.3×108t OIP has been ascertained and placed on production, which accounts for36.68%of the total proven petroleum geological reserves41.71×108t and is an important potential of Shengli Oilfield stable development. At present, most of blocks have entered into extra high water cut period with more than90%water cut and complex residual oil distribution. Block’s shattered trait, serious oil/water well’s casing damage and reservoirs’development characteristics during extra high water cut period mingled together, causing an unfavorable situation with low injection/production perfection degree and rapid decline of rate.To find the injection/production mode which can improve the development effect of block reservoirs in high water cut stage, we carried out the following tasks and obtained the corresponding results and understanding:1) On the basis of understanding essential characteristics of Shengli Oilfield block reservoirs and investigating their classification method, we reclassified the blocks into four categories:narrow ridge type, open type, semi-closed type and closed type.2) According to typical Yong3Block’s basic geological and operational parameters and selected block prototypes of different types, through Petrel geological modeling software we established the geological models which reflect prototype blocks’geological characteristics, including seven narrow ridge type-, six open type-, two semi-closed type-and twelve closed type-(six triangle, six trapezoid) models. And then, using numerical simulation, we studied the plane distribution and enriching patterns of all kinds of blocks’remaining oil during extra high water cut period.3) After doing the feasibility analysis of the crestal gas injection, we performed its optimization of the narrow ridge type block and the injection/production mode (strong flooding, cyclic waterflooding and diverted flooding) optimization of open type, semi-closed type and closed type blocks during extra high water cut period.4) Accroding to the result, we found that the injection modes adopted all are effcective methods of improving the development cffect. However, it has different optimum injection/production mode for different type of block. For example, similar reservoirs like narrow ridge type block are suitable for adopting the crestal gas injection. For other blocks are suitable for cyclic waterflooding, etc. And more closed the block is, more need for greater water injection, making both the areal efficiency and recovery increased.The development law provides a theoretical reference and technical direction for tapping the remaining potential and improving the development effect of block reservoirs during extra high water cut period, and provides some guidiance advice for the later development of a similar oilfield.