A Key Technology Serial to Enhance Oil Recovery at the Ultra-high Water Cut & Ultra-high Recovery Stage in the 4th Block of Gangxi Oilfield

After half a century of development, Gangxi Oilfield has entered the stage of high water cut & high recovery, with more prominent contradiction and growing pressure to maintain stable production year by year. This paper takes the ultra-high water cut & ultra-high recovery reservoir in the 4th block of Gangxi Oilfield as an example. On the basis of previous research achievement, the study of integration of 3D geological modeling & numerical simulation of reservoir configuration level is carried out to clarify 3 kinds of storage status of residual oil. With the help of reconstruction of strata and well pattern of combination of the secondary development & tertiary oil recovery, the calculation method of well pattern equilibrium coefficient is innovatively put forward, and the ‘staggered layer’ 3D well pattern construction mode is firstly formed, so as to guide the preparation of reservoir engineering program in the 4th block of Gangxi Oilfield. After the overall implementation of program, the effect of effect of field implementation is remarkable, that the oil production is increased by more than 100t/d, and the recovery rate is increased by 7% points, reaching a new high in the past 20 years. The key technology serial to enhance oil recovery has a broad prospect for promotion, which breaks traditional concept that it is difficult to deploy new wells in high water flooded zones, and revitalizes a once-abandoned reservoir.