The Effect of Freezing of Slightly Consolidated Cores

Abstract

Summary This paper presents laboratory experimental techniques, procedures, and routine core analysis data of unconsolidated to slightly consolidated core plugs from North Sea reservoirs. The effect of freezing on permeability has been investigated, and results from about 30 core plugs with permeabilities ranging from 0.2 to 12 darcies indicate a considerable change in permeability after freezing. Both increased and decreased permeability were obtained after freezing. For one rock type, the freezing seemed to increase the permeability in cores with initial permeability less than 2 darcies, while decreasing the permeability of core plugs with initial permeability greater than 2 darcies. The observed changes in permeability depend on the amount of kaolinite in the core plugs and the changes in kaolinite morphology during freezing and thawing.