1. n. [Formation Evaluation]

A technique for measuring the bulk volume of a core sample by observing the displacement of mercury in a chamber. The chamber is first filled to a reference level and the volume recorded. The sample is introduced and the new volume recorded. The difference is the bulk volume of the sample. If the sample is weighed, its bulk density can also be calculated. Mercury is used because it is strongly nonwetting and therefore does not enter the pore space.

See: Boyle's Law Double Cell,  Boyle's Law Single Cell,  buoyancy,  core plug,  liquid saturation method,  porosimeter,  routine core analysis,  summation of fluids method