摘要
为了研究气水同注驱油技术扩大水驱波及体积提高采收率的适应性,通过室内驱油实验,评价了氮气-水和氮气-活性水2种体系作为驱油剂的驱油效果,并探讨了各自的渗透率适应界限和驱油机理.实验结果表明：当渗透率为5×10^-3-100×10^-3 μm^2时,氮气-水同注体系的流度降低因子随渗透率的增大而减小;当渗透率为5×10^-3-40×10^-3 μm2时,该体系可有效增大水驱波及效率,提高采出程度35.1%-16.8%.由于流度降低因子与采出程度增值匹配性良好,可将其作为表征气水同注体系扩大波及体积能力的重要指标之一.当渗透率为30×10^-3-500×10^-3 μm2时,氮气-活性水同注体系可有效增大渗流阻力,扩大波及体积,提高采出程度22.6%-19.4%.因此,氮气-水同注体系适用于渗透率小于40×10^-3 μm^2的地层,氮气-活性水同注体系适用于渗透率为30×10^-3-500×10^-3 μm^2的地层.
Dynamic simulation experiments were operated so as to evaluate the recovery efficiency of the two types of simultaneous water and gas injection(SWAG)systems:the nitrogen-water system and the nitrogen-active water system. Their enhanced oil recovery mechanism and permeability adaptability were probed as well. The result suggests that the mobility reduction factor(MRF)of the nitrogen-water system reduces as permeability rises when it ranges from 5×10- 3to 100×10- 3μm2. The nitrogen-water system can enlarge swept volume and improve recovery efficiency by 35.1%-16.8% after water flooding in the scope of 5×10-3to 40×10-3μm2. MRF can be used as a criterion to evaluate the sweep efficiency enlarging ability of SWAG for it matches well with recovery degree. When permeability ranges from 30×10-3to 500×10-3μm2,the nitrogen-active water system can improve percolation resistance effectively and enhance recovery degree by 22.6%-19.4%after water flooding. Therefore,the nitrogen-water system can be adapted to the formation with permeability under 40×10-3μm2,whereas the nitrogen-active water system may be applied to the formation with the permeability between 30×10-3and500×10-3μm2.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2015年第5期89-93,98,共6页
Petroleum Geology and Recovery Efficiency
基金
国家科技重大专项"油田开采后期提高采收率技术"(2011ZX05009-004)
国家科技支撑计划"CO2埋存与提高采收率评价研究"(2012BAC26B02)
关键词
气水同注
波及体积
流度降低因子
渗透率适应性提高采收率
simultaneous water and gas injection
sweep efficiency
mobility reduction factor
permeability adaptability
EOR
