ملخص
Abstract
This study covers the Fields producting from the Gialo Formation a reservoir which is composed of Limestone and Dolomitic-Limestone and consists mainly of highly altered Nummulitic Packstone. This study was achieved through three parts of study including a petrographic study, petrophysical study of reservoir properties from core analysis and borehole logs. The general geological framework was obtained from petrographical study of thirty six thin sections, 129 representative core plug data and logs from 5 different wells are utilized to better understanding the petrophysical framework of the formation. The plots correlating petrophsical parameters and the frequency histograms suggested the presence of distinctive reservoir trends. These discriminations were also represented in Winland porosity- permeability cross plots resulted in clusters for different port-size that are responsible for different flow characteristics. Linear and multiple regression were used for the study of each unit. The permeability models were constructed and their reliabilies were compared by the regression coefficients for predictions in un-cored well. The combination of all data revealed the worst ranked reservoir quality corresponded to moldic and intergranular pore types, which occurred mainly in the Bioclastic Wackstone facies. The highest ranked reservoir quality corresponded to intragranular and intergranular which occurred mainly in the Nummulitic Packstone Facies.