CAJ | 학술논문

BZ25-1油田沙二段储层经过长期注水开发，已进入高含水开发后期，水驱采收率偏低。通过分析气水交替注入提高采收率的作用机理，在物模实验研究的基础上提出采用N2水交替注入实现BZ25-1油田沙二段储层的挖潜控水。实验结果表明，N2水交替注入采收率较单纯水驱采收率提高3．63％。受渗透率非均质性的影响，注入水主要进入高渗透层驱油，并很快从高渗透层突破且含水上升快。注N2综合采收率较水驱略低，主要是N2从高渗透层突破后，降低了低渗透层的驱油效率。 N2水交替驱在一定程度上能改善流度比，降低渗透率非均质性带来的影响，增加驱油效率。
BZ25-1유전사이단저층경과장기주수개발，이진입고함수개발후기，수구채수솔편저。통과분석기수교체주입제고채수솔적작용궤리，재물모실험연구적기출상제출채용N2수교체주입실현BZ25-1유전사이단저층적알잠공수。실험결과표명，N2수교체주입채수솔교단순수구채수솔제고3．63％。수삼투솔비균질성적영향，주입수주요진입고삼투층구유，병흔쾌종고삼투층돌파차함수상승쾌。주N2종합채수솔교수구략저，주요시N2종고삼투층돌파후，강저료저삼투층적구유효솔。 N2수교체구재일정정도상능개선류도비，강저삼투솔비균질성대래적영향，증가구유효솔。
After long-time water-flooding exploitation , BZ25-1 oilfield has entered the later stage of high-water-cut exploitation and the water drive recovery efficiency is rather low .Based on the analysis of the oil recovery enhance-ment mechanism by means of water-alternating-gas injection , and physical model experiment , this paper put for-ward the method of adopting N 2-alternating-water injection for achieving high-water-cut production of BZ 25-1 oil-field.The experimental results show that , compared with the pure water-flooding oil recovery , the oil recovery real-ized by N2-alternating-water injection may increase by 3.63%.Due to the influence of anisotropy of permeability , the injected water mainly enters the oil layer with high permeability and quickly breaks through the oil layer with high permeability , and the water cut rises rapidly .Because the N 2 reduces the oil displacement efficiency of low permeable formation when it breaks through the oil layer with high permeability , the recovery efficiency after injec-ting the N2 is lower than injecting water.N2-alternating-water flooding can improve mobility ratio , reduce the effects of heterogeneity of the permeability and increase oil displacement efficiency .