摘要
将岩石孔隙归结为由毛细管和球形孔组成的孔隙系统 ,提出孔隙球管孔隙模型 .岩石孔隙按大小分组后 ,每一组孔隙的氢核弛豫时间可以用球管孔隙模型计算 .将此弛豫时间作为反演T2 分布的时间控制点 ,反演岩芯的核磁共振弛豫信号 .研究表明 ,T2 分布与特定的孔隙结构相联系 .使用不同结构的球管孔隙模型 ,可以使反演T2 分布最大限度地拟合弛豫信号 ,此时的球管模型以最近似的方式模拟了岩芯的孔隙结构 .使用球管模型对实验室核磁共振资料进行了处理 ,对比压汞分析得到毛管力分布数据 ,结果证明球管孔隙模型描述了岩石孔隙的弛豫特征 ,而且 。
All pores in rock can be regarded as a system consisting of spherical pore and capillary pores. This paper presents a model of sphere-capillary. All pores are divided into different groups by their radii, and the relaxation time of each group can be calculated with the sphere-capillary model. The transversal relaxation time (T 2), spaced on the sphere-capillary model, can be utilized to conduct the inversion of NMR relaxation signal. Our research suggests that the T 2 distribution from the inversion is related with the special pore structure defined by the sphere-capillary model. Using different sphere-capillary models to derive different relaxation times, we conduct the inversion of relaxation signal with the relaxation time. When a T 2 distribution fits the relaxation signal in the least squares, the pore structure defined by the sphere-capillary model characterizes the pore system in rock best. Data from lab NMR measurements are analyzed with the sphere-capillary model, and the results are compared with the pressure data from mercury injection. The result shows that the sphere-capillary model describes properly the relaxation characteristic related with pore structure. Furthermore, the relaxation characteristic may be associated the with pore fluids.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2004年第4期663-671,共9页
Chinese Journal of Geophysics
基金
国家自然科学基金 ( 4 0 2 740 3 3 )
油气藏地质及国家重点实验室开放基金 (PLN0 40 1)资助
关键词
核磁共振
孔隙结构
压汞分析
球管模型
弛豫
岩石物理
NMR, Pore structure, Mercury injection, Sphere-capillary model, Relaxation, Petro-Geophy- sics.
