APLICATION OF PROFILES OF IMAGES TO THE MICROTECTONIC STUDY OF AN OFFSHORE OIL FIELD IN THE FRANJA NORTE DE CRUDOS PESADOS OF CUBA

摘要

The studied oil field presents accumulations of petroleum in clastic carbonate rocks of Tertiary age deposited in a very unstable foreland basin. Due to the action of strong compressive events the rocks were intensively folded and fractured. Such a tectonic regimen gave place to the formation of traps of folds against inverse faults, typical for the whole Franja Norte de Crudos Pesados of Cuba. From interpretation of the image profiles (FMI and FMS) of many horizontal wells in an offshore area a detailed microtectonic study was carried out. Furthermore, to clarify the relationship stress - strain for the area in question a detailed characterization of the fracturing, folding, microfaulting and electrofacies and lithofacies studies were made. In the first place, a data bank was collected with the information of the FMI images of all wells for the later realization of the statistical treatment that allowed the determination of fracturing and the deformation preferential directions. It was possible to make: 1. Rose diagrams for each type of deformation, 2. Maps of density of fracture, and 3. The ellipsoid of stresses. All to deduce questions related with tectonic aspects of major scale. The map of distribution of the conductive fractures (opened and partially opened) in the wells was correlated with the lithofacies distribution and the structural maps for the knowledge of the influence of the tectonics in the improvement of the reservoir properties.