Anisotropic Variation Law of Rock Permeability with the Burial Depth of Limestone

作     者：TIAN Kaiming, WAN Li and TIAN Jiping Department of Water Resources and Environmental Science, China University of Geosciences,27 Xueyuan Road, Beijing 100083, Department of Computer Sciences, Guangzhou University, Guangzhou, Guangdong 510091 

作者机构：China Univ Geosci Dept Water Resources & Environm Sci Beijing 100083 Peoples R China Guangzhou Univ Dept Comp Sci Guangzhou 510091 Guangdong Peoples R China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2003年第77卷第1期

页      面：125-128页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 0708[理学-地球物理学] 

主　　题：macrofracture system microfracture system permeability tensor permeability ellipsoid 

摘      要：Permeability tensors of both macrofracture and microfracture Systems weremeasured progressively along the depth of limestone formations at severed sites. It was found thatthe principal permeability values K_x, K_y and K_z in these permeability tensors all decreasesimultaneously and logarithmically with depth. However, the limestone aquifers are composed of anupper region where the larger permeability ellipsoid is upright or prolate and characterized byK_zK_x and K_zK_y, a transitional zone, and a lower zone whose smaller permeability ellipsoid ishorizontal or oblate and characterized by K_zK_x and K_zK_y. The inversion of the permeabilityellipsoids in direction indicates that the anisotropy of rock permeability with the depth oflimestone formations has evidently changed. The anisotropic variation law of permeability tensors ina macrofracture system displays a similar pattern with that in a microfracture system. It is nextto impossible to examine the rock permeability tensor of the aquifer just by measuring the hydraulicparameters of macrofracture system directly, unless the limestone aquifer is exposed on or near theearth s surface. Therefore, the permeability tensors of a macrofracture system at any depth may beindirectly and roughly determined from the gaugeable permeability tensors of the microfracturesystem by conversion. This anisotropic variation law of rock permeability with depth is of greatsignificance in the study of three-dimensional fracture water flow the huge carbonate formations andin the research on the conditions of karst development and karst distribution.