Correlation between rock fabrics and physical properties of carbonate reservoir rocks

Three carbonate core samples from an oil and gas reservoir of the NW German basin were chosen to study the correlation between rock fabrics and physic al properties of reservoir rocks. Detailed fabric analyses and texture inve stigations were carried out as well as laboratory measurements of different physical properties, e.g, density, porosity, permeability, electrical cond uctivity, seismic compressional and shear wave velocities, Although the thr ee core samples come from a similar depositional facies, they show great di fferences in the occurrence and three-dimensional distribution of the rock fabric elements. These heterogeneities are the result of various diagenetic and tectonic processes. For the correlation between the rock fabrics and t he physical properties four main rock fabric types have to be considered: ( a) major constituents, e.g. fossils, ooides, peloides and crystals; (b) por e space with different pore types: (c) fractures; and (d) stylolites. The r esults of the correlation clearly show that the values and anisotropies of the petrophysical properties are fairly related to the observed fabric elem ents, with their different arrangements, spatial distributions and preferre d orientations. These results also provide a fundamental understanding of t he petrophysical responses, such as seismics? to the different geological f eatures (e.g. fractures) and their dynamic changes with pressure, which can be converted to different depths. The knowledge gained from such correlati ons may lead to an improved interpretation of geophysical data for hydrocar bon exploration and production and therefore to an advanced reservoir chara cterization.