Complex nature of separated solid phases from crude oils

Precipitated solid phases from oil wells and storage tanks have hampered oil operations and decreased revenues in Venezuelan facilities during recent decades. Physicochemical characterization of oils and separated solids was undertaken 6 years ago to understand the phenomenon and contribute to its prediction under production conditions. A multidisciplinary approach was followed, adopting diverse gravimetric, spectrometric, and chromatographic procedures. The purpose of this contribution is to summarize some of the most relevant findings from this research. Emphasis was focused more on the analytical aspects rather than on the engineering ones. Three groups of variables were assessed simultaneously to help in solving the problem. These were (I) the intrinsic nature of crudes, (II) mineral and porous matter effects, and (III) operational variables.