Identifying productive zones of the Sarvak formation by integrating outputs of different classification methods

The Sarvak formation is the second major carbonate reservoir in Iran. There are several geological, petrophysical and geophysical investigations which have been carried out on this important reservoir. In this paper, the Sarvak is studied in order to determine productive zones. First, four different methods are used to identify producing intervals from well log data and well test results. Then, final zoning is generated by integrating the outputs of these four methods. One of them is the conventional cut-off-based method; the other three are based on flow equation, Bayesian and fuzzy theories. Thereafter, by considering the classification correctness rate of each classifier in each well and technique of majority voting, a unique zoning for the Sarvak formation is presented. Based on the final zoning, the whole Sarvak interval is divided into seven zones. Three of them are classified as oil-producing zones, two of them cannot be classified as conventionally producing zones, and the remaining two are water producing. Zone 2 not only has the highest production rate, but is also the most homogeneous zone among the productive zones. The novelty of this research is using well test results in defining productive classes, which improves the certainty of classification in comparison with previous works that were based on core analysis and log data.

[1]  A. Bashari.  THERMAL HISTORY RECONSTRUCTION IN THE SOROOSH AND NOWROOZ FIELDS, PERSIAN GULF, BASED ON APATITE FISSION TRACK ANALYSIS AND VITRINITE REFLECTANCE DATA , 2008 .

[2]  Valentin B. Shehtman.  On squares of modal logics with additional connectives , 2011 .

[3]  Pedram Masoudi,et al.  Developing a method for identification of net zones using log data and diffusivity equation , 2012 .

[4]  S. Sherkati,et al.  Variation of structural style and basin evolution in the central Zagros (Izeh zone and Dezful Embayment), Iran , 2004 .

[5]  Riyaz Kharrat,et al.  Incorporating Fuzzy Logic and Artificial Neural Networks for building a Hydraulic Unit-Based Model for Permeability Prediction of a Heterogeneous Carbonate Reservoir , 2009 .

[6]  E. Kazemzadeh,et al.  FLOW UNIT CLASSIFICATION FOR GEOLOGICAL MODELLING OF A HETEROGENEOUS CARBONATE RESERVOIR: CRETACEOUS SARVAK FORMATION, DEHLURAN FIELD, SW IRAN , 2007 .

[7]  A. Ghabeishavi,et al.  Microfacies and depositional environment of the Cenomanian of the Bangestan anticline, SW Iran , 2010 .

[8]  B. Bohloli,et al.  Subsurface fracture analysis and determination of in-situ stress direction using FMI logs: An example from the Santonian carbonates (Ilam Formation) in the Abadan Plain, Iran , 2010 .

[9]  L. Cosentino,et al.  The Role of Cut-offs in Integrated Reservoir Studies , 2005 .

[10]  Ethem Alpaydin.  Combining Pattern Classifiers: Methods and Algorithms , 2004 .

[11]  G. James,et al.  Stratigraphic Nomenclature of Iranian Oil Consortium Agreement Area , 1965 .

[12]  A. Piryaei,et al.  LATE CRETACEOUS TECTONIC AND SEDIMENTARY EVOLUTION OF THE BANDAR ABBAS AREA, FARS REGION, SOUTHERN IRAN , 2011 .

[13]  Ludmila I. Kuncheva,et al.  Combining Pattern Classifiers: Methods and Algorithms , 2004 .

[14]  P. Worthington.  Net Pay--What Is It? What Does It Do? How Do We Quantify It? How Do We Use It? , 2010 .

[15]  J. Zumberge,et al.  Petroleum system analysis of the Mishrif reservoir in the Ratawi, Zubair, North and South Rumaila oil fields, southern Iraq , 2009, GeoArabia.

[16]  Dennis Denney,et al.  Net Pay: What Is It? What Does It Do? How Do We Quantify It? How Do We Use It? , 2010 .

[17]  A. Piryaei,et al.  The influence of Late Cretaceous tectonic processes on sedimentation patterns along the northeastern Arabian plate margin (Fars Province, SW Iran) , 2010 .