Experimental Investigation of Drainage Capillary Pressure Computed From DigitizedTomographic Images

摘要

This paper presents comparisons between drainage capillarypressure curves computed directly from 3D microtomographicimages (micro-CT) and laboratory measurementsconducted on the same core samples. It is now possible tocalculate a wide range of petrophysical and transportproperties directly from micro-CT images or from equivalentnetwork models extracted from these images. Capillarypressure is sensitive to rock microstructure and thecomparisons presented are the first direct validation of imagebased computations. The measured data include centrifugeand mercury injection drainage capillary pressure for firedBerea, Bentheimer and Obernkirchner sandstones and unfiredMount Gambier carbonate. The measurements cover a widerange of porosities and permeabilities. The measurements aremade on core samples with different diameters (2.5 cm, 1.5cm, 1 cm and 0.5 cm) to assess the effect of up-scaling oncapillary pressure measurements. The smallest diametersamples were also used to obtain the 3D micro-CT images.Good agreement is obtained between the experimentalmeasurements and direct computations on 3D micro-CTimages.