A method for determining spatial distribution and concentration of clay in a core sample

摘要

Abstract A water-soluble salt of a metal with a high atomic weight is selected as an X-ray contrast substance providing a selective ion-exchange reaction with a clay. The salt has a general formula R*M~, where R* is selected from a group consisting of Ba2+; Sr2+ 5 Tl' ; Rb* ... , and M~ is selected from a group consisting of Clv; NO,; OHn; CH3 COO, SO4 ; ... in accordance with a standard table of inorganic substances' water solubility. The X-ray contrast substance is injected into a core sample. Upon completion of the selective ion exchange reaction a non-contrast displacing agent is injected into the sample. The sample is scanned by computer X-ray microtomography and an image of 10 the sample is obtained. An area of interest and a reference cross-section are selected at the obtained computer tomography image. Grayscale histograms in cross-sections of the sample are obtained. Spatial distribution and concentration of the clay is estimated by means of histograms analysis starting from the reference cross-section histogram. 3447814_1 (GHMatters) P90739.AU 22-.un-12 0.02 -_ Length, mm Fig. 3