摘要
采用溶解气驱开采超重油后,仍有大量残余油存在,为了进一步开发超重油潜力,开展了不同条件下超重油溶解气驱转驱方式对驱油效率影响实验。实验结果表明:在均质模型基础上,一般溶解气驱采收率约为10%,而溶解气驱后进行蒸汽驱或二氧化碳转驱都可在一定程度上提高最终采收率,其中实施溶解气驱后转蒸汽驱剩余油饱和度更低,平均采收率在70%以上,而转二氧化碳驱后平均采收率仅约为25%。另外,通过分析发现,压降速度、温度和渗透率等因素对溶解气驱开采效果都有一定影响,其中压降速度加快可适当增加驱替速度,在一定的时间条件下,压降速度越快,提高采收率效果越好。温度的影响则存在明显的时间效应,其值越低,溶解气驱提高超重油采收率的效果越明显;渗透率对提高采收率效果的敏感性较低,较高的渗透率有助于提高驱替速度。
Since amounts of residual oil still remains after dissolved gas drive in super heavy oil reservoir,effects of flooding conversion on oil displacement efficiency were studied through experiments under various conditions focusing on this problem. The lab experiment results illustrate that the oil recovery by the traditional dissolved gas drive for homogeneous lab core model is about 10%. Either steam stimulation or CO2 stimulation after dissolved gas driving stimulation can enhance oil recovery to some extent. Steam stimulation is more applicable with a final oil recovery of more than 70%,whereas the oil recovery after CO2 stimulation can only achieve about 25%. Additionally,the influences of the pressure drop speed,temperature and permeability on oil recovery are different. A faster pressure drop can lead to a faster recovery speed and enhance recovery efficiency for a certain time. The oil recovery is controlled by temperature with time effect. Lower temperature can enhance oil recovery. The effect of formation permeability on the oil recovery is limited,and a higher permeability can boost recovery speed.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2015年第1期98-101,121,共5页
Petroleum Geology and Recovery Efficiency
基金
国家"863"计划"注气辅助SAGD技术研究与现场试验"(2009AA06Z205)
关键词
超重油
溶解气驱
转驱
提高采收率
压降
温度
super heavy oil
dissolved gas drive
flooding conversion
enhanced oil recovery
pressure drop
temperature
