Petrophysical evaluation of a carbonate reservoir in Campos Basin - Southeastern Brazil

Abstract

Summary In this work, we analyzed geological, geophysical, and petrophysical data sets for two wells to assess the carbonate reservoir of Field A in Campos Basin - southeastern Brazil. Geological data refer to interpretation of cores samples, geophysical data to well logs, and petrophysical data to laboratory tests of capillary pressure by mercury injection, retort, membrane, and centrifugal saturations. The purpose of this study is to test our hypothesis that it is possible to achieve a more accurate profile of the distribution of the properties of reservoirs through a qualitative and quantitative analysis of integrated data sets. Thus, a qualitative interpretation was made by the joint plot of the data, with results showing a good agreement between the different data types for the two wells. Then, a quantitative interpretation was made by first calculating the quality of the reservoir in accord with the proposal of Amaefule et al. (1993), and, subsequently, inverting the water saturation, which showed a good concordance when compared with different types of saturations of well A3. The inverted Archie parameters of well A3 showed an excellent fit when applied to calculate well A10 saturation. Results show that the adopted interpretive approach improves the petrophysical evaluation, indicating it can be extended to the other 25 existing wells in this field.