An adhered organic deposit, formed within the petroleum well on the steel surface of the tubing walls,
was systematically characterized following a sequence of bulk and surface techniques. The results allowed
the identification of the tubing wall and its internal surface structures. As a consequence of the contact
with sulphur-bearing compounds such as H2S and brine from petroleum, the pre-oxidized steel surface
was modified by non-stoichiometric iron compound formation. These new iron phases favour adsorption
and chemisorption of the petroleum polar compounds on the steel surface. Copyright 2002 John Wiley
& Sons, Ltd
