摘要
鄂尔多斯盆地上三叠统延长组河流-湖泊三角洲相砂岩储层物性受沉积—埋藏—成岩等因素控制。特低渗透储层具有其独特的微观孔隙结构和渗流机理。应用X-CT扫描成像实验技术进行砂岩岩心微观孔隙结构水驱油驱替实验,通过CT扫描切片图像观察分析了注入水微观驱替渗流机理及不同注入压力下的水驱油效率变化分布规律(实验岩心的水驱油效率最高为62%,最低为42%,平均为51.6%),定量评价了储层微观孔隙结构特征。实验表明低孔、低渗和储层微观双重孔隙结构是造成注入水启动压力、水驱油效率差异大的根本原因;而较强的微观孔隙结构非均质性,是造成注入水波及效率不高、水驱油效率较低的主要原因。
The physical characters of river-lake-delta sandstone in yanchang formation are controlled by deposition,burying, diagenesis and etc. in upper Triassic sandstone in ordos Basin. There are unique micro-pore texture and percolation mechanism in ultra-permeable reserior. Applying the technique of X-CT scanned image', the water driving oil test was made. By observing the CT scanned slice, the micro-percolation mechanism and the distribution law of water driving of rate (the highest water driving rate, 62%; the lowest, 42% average, 51. 6% were analysized, and micro-porosity character was evaluated quantitively. The essential reason that the great difference exists in parameters of starting pressure and water driving oil rate lies in low porosity, low permeability and double-porosity texture. The evident anisotropism is the main reason of low sweep efficiency and water displacement efficiency.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2006年第5期775-779,i0009-i0010,共7页
Acta Geologica Sinica
基金
国家重大基础研究发展规划"973"项目(编号2003CB214600)
长江学者和创新团队发展计划(编号IRT0559)资助的成果。
关键词
X-CT成像
特低渗储层
微观孔隙结构
渗流机理
非均质性
启动压力
水驱油效率
X-CT scanned image
ultra-permeable reservior
micro-pore texture
percolation mechanism
heterogeneous
starting pressure
water driving oil rate