摘要
通过大庆外围特低渗透储层岩芯一维物理模拟实验，研究注水、注气、注水转注气这3种方式的驱油微观机理，对现场注水转注CO2提出可参考性建议。实验中主要利用了CO2的萃取、降黏等特点，与水驱相比，CO2驱驱油效率更高，增油效果明显。实验表明：对于低渗透储层，注水开发效果最差，约为40％；不同注水时机转气驱效果均好于水驱，而且注水时机越早采出程度越高，在10％～20％含水率转注气能有较好的经济效益；注气驱采出程度最好且采出程度都能达到67％左右。通过核磁信号测量，对比不同开发方式的剩余油分布可以得出，水驱和气驱动用的主要都是大孔隙中的油，而水驱转气驱由于CO2的波及范围更广，能对小孔隙中的部分原油进行动用。
Through one-dimensional physical simulation experiment with the cores of ultra low permeability reservoir in the peripheral part of Daqing, this paper studies the micro mechanism of oil displacement mechanism by water flooding. CO2 flooding and CO2 flooding after water injection, furthermore, the suggestion for the field application of gas flooding after water injection is put forward. The main advantage of this experiment is reducing oil viscosity and extraction of CO2, etc. Compared with water flooding, CO2 flooding oil displacement is more efficient with notable oil increment. Result shows that： for low permeability reservoir, the effect of water flooding is the worst, about 40%, at different time of water injection gas driving can lead to better effect, the earlier timing of water injection the better effect, to have better economic benefits the rate of water content should be 10%-20% ; flooding recovery degree is best by gas injection, can reach to about 67%. By means of NMR, we can compare the different development ways, CO2 displacement and water displacement extracts most of movable fluid in macro pores, however, the CO2 can increase the sweep volume effectively after water injection, which also make the parts of the small pore crude oil become movable.
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第4期161-165,共5页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家油气重大专项(2011ZX05013-006)
中国石油天然气集团公司重大基础攻关课题(2014B-1203)
关键词
CO_(2)驱油
微观驱油机理
可动流体
低渗透油藏
核磁共振
CO_(2) flooding
the micro mechanism of oil displacement
moveable fluids
low permeability reservoir
nuclear magnetic resonance
