Mineralogía de las rocas sello en la franja norte de crudos pesados.

The north fringe of heavy crude represents the main source of Cuban hydrocarbons. Gas and oil seals of Cuban Northern Province are represented by a series of orogenic formations consisting mainly of terrigenous rocks with clay components. For seal quality evaluation of these formations, petrography and mineralogical characterization are essential. The primary sealing elements of Cuban northern province are clays, which are defined as the fundamental object of this research. They are distinguished by having a lower crystallinity than carbonates, effect that is caused by crystal imperfections: crystallite size, structural disorder and stress, while carbonates have a chemical composition that includes a smaller number of chemicals that showing clays. For this characterisation it was applied the infrared spectroscopy and x ray diffraction techniques. For this purpose samples were taken from clays and carbonate rocks of drill cores and geological outcrops. The application of these techniques allowed the determination of the composition of the rocks, characterized by the complex mixture of: illite, smectite, chlorite and hydromica (hydromuscovite) accompanied by their respective interlayereds. [ABSTRACT FROM AUTHOR]