Effect of brine composition and clay content on the permeability damage of sandstone cores

摘要: Abstract Permeability damage due to the water sensitivity of three types sandstone cores was studied. X-ray diffraction showed that contain varying amount clays and Aramco have a higher ratio smectites (6% relative abundance among clay families) than other two sandstone. Chemical analyses were carried out determine base exchange capacity exchangeable cations in untreated extracted from cores. To assess further effect ions, ageing NaCl, MgCl 2 CaCl alter ions prior displacement runs. The critical salt concentration ( CSC ) permeability drop used as criterion for measuring sensitivity. run can be expressed function cations. maximum observed 86% 0.63 wt% (0.149 M established when displacing with aqueous LiCl solutions decreasing concentrations. Varying solution had large on sensitivity; reduced 13.5% 0.13 (0.006 BaCl Changing anions minor compared changes