Flow-units verification, using statistical zonation and application of Stratigraphic Modified Lorenz Plot in Tabnak gas field

Abstract

The relationship between two main reservoir parameters being porosity and permeability, in the carbonate rocks is very complex and obscure. To get a better understanding on flow behavior, the relationship of porosity and permeability of reservoir units, reservoir zonation and flow units were defined. The significance of dividing the sedimentary intervals into flow units reflects groups of rocks that have similar geologic, physical properties and depositional environment that affect fluid flow. Variations in rock properties result from depositional, diagenetic and post-depositional changes. A flow unit is a volume of a reservoir rock that is continuous laterally and vertically and has similar averages of those rock properties that affect fluid flow. Different methods exist for the zonation of reservoirs based on petrophysical data and well logs; among them are: Permeability–Porosity cross plot, Pickett and Soder and Gill methods. In this study, the flow units are determined in Tabnak gas field in South of Iran based on Testerman Zonation Technique and Stratigraphic Modified Lorenz Plot (SMLP) methods. For determining these units, conflation of petrophysical data and comparing porosity and permeability of cores are done for verification three wells. By comparing flow-units derived from two methods, it was realized that in permeable zones they have a relatively valid correlation.