Rock Porosity Determinations Using Particle Densities Measured in Different Fluids
Rock porosity, when calculated from measurements of bulk and particle rock density, is found to depend on the method used to determine these densities. The particle density, which is found experimentally, varies with the immersion fluid used; hence, the porosity determined depends on it, too. Organic fluids are recommended in standards for describing particle density for special applications; however, water is generally considered to be virtually inert when in contact with inorganic particles, particularly if the particles are composed of silicates. Thus, the results of measurements made using water as the immersion liquid are not considered to have been measurably affected by water. This paper shows that water does, in fact, alter measurably the value of silicate particle density obtained compared with measurements made using an organic fluid, viz., n-heptane. Explanations for this finding are under further consideration.