Technology Of Subsequent Water Flooding Cyclic Studying In Naner Area Saertu Oil Field

As the contradictions of hydrocarbon development being more and moresharpening, secondary development has became the focus of oil field. This study tookthe subsequent water flooding block in the second area south of Sanan oilfield inDaqing oilfield as the object based on reservoir precise anatomy. The remaining oilpotential in subsequent water flooding block and distribution rules were made clear;the change rule for distribution of residual oil after polymer flooding and recovery andpymer concentration were understood for further; the characteristics of dynamicchange of subsequent water flooding were made clear. The periodinjection-production experiment was done in the subsequent water flooding block，in which the relationship between branching line and main streamline was adjusted，the direction of liquid flow was changed and new underground flow field was formedeventually. Then low effective cycle was controlled and the residual oil in the thick oilreservoir was digged for further through optimizing the injection method, intensityand half-period under the condition of great well spacing. After the periodinjection-production, the pressure field was re-distributed, the areal liquid flow waschanged, and the vertical thin and poor reservoir was effective employed. The methodof period injection-production with different injection intensity and well space fromthe entire well to layers adjusted the relationship between branching line and mainstreamline effectively and formed new underground flow field. As the productionliquid composition was adjusted, the output ratio of the high production liquid to highwater cut dropped, while the ration of hygroscope thickness of thin and poor reservoirraised, and the residual oil in poor water cut layer was employed. Through this study,the rise of water cut in the stage of subsequent water flooding was controlled and theeffective method for enhancing recovery was explored for further. The main worksand achievements are as follows:1． Through fine reservoir description and reservoir anatomy, the reservoirstructure and the development and extension of sand bodies were re-recognized;the relationship between injection and production of single sand body wasanalyzed, and the residual oil potential was implemented.2． Distribution rules of residual oil were studied applying the technology ofnumerical simulation to implement the residual oil potential. 3． The relationship between branching line and main streamline was changedthrough period switch of injection-production wells, which improved thecondition of employed reservoir and Enhanced Oil Recovery. The position ofbranching line, residual oil and thin-poor reservoir were all employed. Besides,the ratio of the high production liquid with high water cut was controlled and itsgrowing was avoided. The water cut in the well area decreased and betterdevelopment effect was obtained.