特低渗透油田注空气驱油调研及认识

海塔油田经过近十年的勘探开发,年产油已达80×104t,成为大庆油田外围上产的主产区.但海塔油田探明储量中特低渗透储量比例高,渗透率小于2×10-3μm2的储量接近一半.针对海塔油田特低渗透储量比例大,常规注水开发难以有效动用的实际,积极探索特低渗透油田难采储量有效动用新途径.通过国内外文献调研,对特低渗透油田注空气技术,包括适用条件、注入方式和用量、跟踪分析调整、应用效果、采油工艺及地面设备等进行调研,为特低渗透油藏实施注空气驱油提供借鉴.同时,结合海塔油田的实际,在国内海拉尔油田优选出先导试验区,开展注空气驱现场试验,见到了初步效果.试验结果表明,海拉尔油田注空气驱油具有一定的可行性,可以有效动用部分难采储量,加快海塔油田上产步伐.可见,对于特低渗透油藏,空气驱的技术经济效益明显好于水驱,注空气开发技术可作为一项战略性技术储备,为提高特低渗透油藏最终采收率提供技术支撑.

Research and Understanding of Oil Displacement by Air Injection in Extra-low Permeability Oil Fields

Hailar-Tamtsag oilfields have been the main producing areas of Daqing peripheral oilfields with 80×104t of yearly oil production for ten years′ exploration and production.But extra-low permeability reserves take high proportion of the proven reserves in the oilfields,and reserves with the permeability less than 2×10-3μm2 account for 50.1% of the proven reserves.According to the actual of the large proportion of the extra-low permeability reserves and difficulty on the effective production by normal waterflooding,new way for effective production of hard-produced reserves in the extra-low permeability oilfields is researching.We researched more than 50 articles on air injection technology in the extra-low permeability oilfields including applicable conditions,injection way and volume,analysis and adjustment by tracking,application result,oil production technology and ground equipment.It will provide reference for air drive in the extra-low permeability oil reservoirs.Pilot test site is optimized in Hailar oilfield,and air drive is carried out.The results show that air drive has certain feasibility in Hailar oilfield.It may make hard-produced reserves effectively produce and oil production rising in Hailar-Tamtsag oilfields.Economic benefit of the air drive is better than that of the waterflooding in the extra-low permeability oil reservoirs.So the technology may enhance the ultimate recovery in the extra-low oil reservoirs as a strategy technical storage.