تعيين گروههاي سنگي با استفاده از مفهوم واحدهاي جرياني و روش تحليل خوشه اي: مطالعه موردي از سازند داريان، ميدان پارس جنوبي، خليج فارس

Identification of rock types Using flow units concept and cluster analysis: A case study from Dariyan Formation, South Pars field, Persian Gulf.

Dariyan formation of Aptian age is major the oil reservoirs in the South Pars field. Occurrence of the worldʹs great unconformity at the end of Aptian, has caused the formation is strongly influenced by the meteoric diagenesis processes and development of dissolution pores. The goal of reservoir characterization is to study Reservoirs properties such as porosity, permeability and water saturation. The porosity-permeability relationships in the framework of hydraulic flow units can be used to characterize heterogeneous reservoir rocks. A flow unit is defined as correlatable and mapple zones latterally and vertically within a reservoir which control fluid flow and is significantly different from those of other rocks. Each flow unit is characterized by a flow zone indicator (FZI). So, reservoir zonation with the use of flow zone indicator and identification of flow units can be used for evaluating the reservoir quality based on porosity-permeability relationships. In this study, the Dariyan formation is divided into five hydraulic flow units based on flow zone indicator variations. In order to study the reservoir quality of the facies, the percentage of the identified flow units was calculated in each facies. In the second stage of study, a cluster analysis approach is used to classify reservoir rock types. The goal of cluster analysis is to classify data into groups called cluster, so that the data within each group have no significant differences with each other. In the present study, five clusters were identified based on porosity and permeability data. Finally, in order to establish a connection with rock fabrics, the reservoir quality of the rock facies was evaluated in each cluster, independently. Both methods show satisfactory results in reservoir study of the Dariyan formation in the South Pars field.