泡沫空气段塞驱油技术在潜山油藏的应用

Application of Foam-air Slug Displacement Technique in Buried-hill Reservoirs

百色盆地上法油田百4块碳酸盐岩潜山油藏从1996年9月开始空气泡沫驱试验取得了显著的降水增油效果,但由于泡沫成本昂贵,难以大规模注入,而相同地下体积的空气成本为泡沫成本的1/8,取之方便、成本低廉。通过研究,在泡沫驱技术的基础上发展应用了泡沫-空气段塞驱,于2001年开始至2010年12月底在百4块实施,经过10年的现场应用,共进行29井次施工,累计注入泡沫液1.84×104 m3、空气1445.3×104 m3,增油1.27×104t,投入产出比为1∶3.14,预计原油采收率可提高4.16%。应用结果表明,泡沫-空气段塞驱能大规模注入补充碳酸盐岩潜山油藏的地层能量,泡沫段能有效延长空气在地下的滞留时间,与地下残余油可以发生低温氧化反应,产出气氧含量在2.5%以内,安全可靠。泡沫-空气段塞驱兼有泡沫驱、空气驱的双重优点。

The air-foam flooding was started in September,1996 in carbonate buried-hill reservoirs of Block Bai 4 in Shangfa Oilfield of Baise Basin,by which a good effect of water reduction and oil increment was obtained.But because of high cost of foam,it was hard to inject it at a large scale.While the air of the same in-situ volume only cost 1/8 of the foam,it was easy to be obtained with low cost.Through researches and on the basis of foam flooding,a technique of foam-air slug displacement was developed and it had been used from 2001 to the end of 2010 in Block Bai 4,it was used in 29 wells with accumulated foam flooding of 1.84×104m3,air injection of 1445.3×104m3 and oil increment of 1.27×104t,its investment-production ratio was 1∶3.14,it was predicted that 4.16% oil recovery could be raised.The result indicates that the slug displacement can be used to compensate the formation energy in carbonate buried-hill reservoirs,the foam slug can effectively expand underground lag time of air and perform a low temperature oxidation reaction with in-situ residual oil,the oxygen content of produced air is within 2.5%,it is safety for application,the foam-air slug has the advantages both of foam flooding and air drive.