Study on the C 0 – C w relationship of clay-bearing sandstones based on digital cores

Acta Geophysica

article

Fan, Yufei¹  Pan, Baozhi¹  Mo, Xiuwen¹  Guo, Yuhang¹  Lei, Jian¹ 

[1] College of Geo-exploration Science and Technology, Jilin University

关键词: Clay-bearing sandstones;    Electrical conductivity;    Finite-element method;    Digital core;    C 0;    C w relationship;   

DOI  :  10.1007/s11600-020-00410-7

学科分类：地球科学(综合)

来源: Polska Akademia Nauk * Instytut Geofizyki

【 摘 要 】

Based on the three-dimensional digital core of Berea sandstone, three-phase (matrix, wet clay and free water) digital cores of clay-bearing sandstone are constructed. We divide clay into structural clay and dispersed clay according to the location where clay growth occurs. The finite-element method is used to simulate the electrical characteristics of digital cores in order to study the relationship between the conductivity of core saturated with brine (C0) and the brine conductivity (Cw). The influence of clay mineral type, content and porosity on core electrical characteristics is taken into account. The results show that the additional conductivity is related to the clay minerals, and montmorillonite has the highest cation exchange capacity, resulting in the largest additional conductivity. The increase in clay content in cores increases the conductivity of core C0. At the same time, clay that fills pores decreases the porosity and causes the decrease in C0. These are two opposing factors of conductivity that coexist in clay-bearing sandstone.

【 授权许可】

Unknown