Estimativa de porosidade em lâminas petrográficas através da morfologia matemática binária

Abstract

Oil exploration in offshore basins needs for drilling boreholes with high angle and horizontal wells, aimed at optimizing the number of exploration targets hit by a single platform. In these cases, it is technically impossible to carry out the coring operations, which prevents core analysis for direct measurement of porosity. In some situations in formation evaluation the geological knowledge of the area may help when there is low confidence in the porosity values. For the semi-submerged basins, the lateral continuity of geologic layers may allow sampling of outcrops in the immersed part of the basin. In the case of offshore basins, may be collected hand samples in outcrops of analogous formations. A relatively common problem in a petrophysical laboratory is the extraction of plugs adapted to the measuring equipment, directly from rock samples collected from outcrops. On the other hand, for this type of rock sample is trivial to obtain thin sections. The objective of this work is to estimate porosity directly on the petrographic images using the image processing method, known as mathematical morphology, which aims to describe quantitatively the geometric structures (forms) in this image.