摘要
对于复杂孔隙结构储层而言,孔隙结构对电阻率的影响程度可能远大于流体类型对电阻率的影响,这就使得气、水层的电阻率特征差别不明显,利用电阻率不能有效区别气、水层。基于孔隙中天然气与油、水体积模量的显著差别,根据孔隙流体体积模量的大小来识别气、水层。研究采用了纵横波速度比(vp/vs)和孔隙流体的体积模量这两个与电阻率无关的弹性参数来判别储层的流体类型。理论模拟表明含有少量气体时可使纵波速度及其纵横波速度比显著减小,横波对气体含量不敏感,水层的vp/vs显著大于气层。采用vp/vs与横波交会法识别气、水层可消除孔隙和岩性的影响而突出流体类型的影响。
The influence of the pore structure on resistivity is much greater than that of fluid type for reservoirs with complex pore structure, which has little difference in resistivity between gas reservoirs and water reservoirs. So, it is difficult to distin- guish them with resistivity. Pore fluid bulk modulus is used to identify gas or water reservoirs based on the marked difference between gas bulk modulus and water（ or oil） bulk modulus. The ratio of compressional wave and shear wave velocity and elastic parameters arc used to determine the fluid type. The simulating results show that a small quantity of gas can cause significant Up and Up/Us decreas, and Us is insensitive to the gas content, and Up/Us of water reservoirs are much significantly greater than that of gas reservoirs. A cross plot of Up/Us versus Us can be used to identify gas or water reservoirs. This cross plot can eliminate the effects of porosity and lithology on Up/Us.
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2012年第3期83-88,共6页
Journal of Southwest Petroleum University(Science & Technology Edition)
