CLASSIFICAÇÃO DE ELETROFÁCIES DE UM POÇO PETROLÍFERO DESCOBRIDOR UTILIZANDO ESTATÍSTICA MULTIVARIADA: UM ESTUDO DE CASO NO CAMPO CURIMÃ (BACIA DO CEARÁ)

Electrofacies classification of a oil discovery well using multivariate statistics: a case-study in Curimã Field (Ceará Basin)

Abstract

Oil industry has been used many techniques in order to characterize reservoirs and  Petrophysical characterization is one of the most important. This work uses data from petrophysical profiles from discovery well 1CES_0019 of the Curimã Field, Ceará Basin, with the objective of classifying electrofacies using multivariate statistics. Analyzes such as basic statistics, Correspondence Analysis and Discriminant Analysis were performed. As a result, five electrofacies were obtained: EF1, EF2, EF3, EF4 and EF5. EF1 is characterized by low GR values; EF2 and EF4 are characterized by lower DT and higher RHOB values; and EF3 and EF5, highlighted by high RHOB values and different DT. EF4 is interpreted as sandstones and well compacted shales from the lower portion of the Paracuru Formation. EF2 is the intermediate portion of the Paracuru Formation, interpreted as Trairi Member composed by carbonate rocks. EF1 is the upper portion of Paracuru Formation, interpreted as clean sandstones with the best reservoir conditions. EF3 is interpreted as shales from Ubarana Formation: sealing rocks. It is important to mention the relevance of calculating the electrofacies and the use of multivariate analysis since only through the observation of the petrophysical profiles it would not be possible to reach the result achieved.