Abstract

Wettability has a dominant effect in well stimulations, in oil recovery by waterflooding, and in many other processes of industrial and environmental interest. This paper brings the capability of X-ray photoelectron spectroscopy (XPS), and also of ion scattering spectroscopy (ISS) to bear on the wettability evaluation of model glass surfaces, and producing reservoir rocks. Mineralogic composition of both kind of substrates reveals quartz as a major constituent. For a suite of freshly-exposed fracture surfaces of rocks,the relationship between wettability and surface composition, as determined from XPS, is investigated. The classical wettability index, as measured with he Amott-Harvey test, is used as an indicator of the wettability oi natural sandstones. A new interpretation of the wetting indices allows discrimination of the various wettability syndromes. To assess the influence of non-pore surface in the XPS results, the ISS …