Study of reservoir quality changes of upper Sarvak formation in one of Persian Gulf fields

Abstract

The purpose of this study, is assessment of petrophysical parameters of Sarvak reservoir in different points of field and compares them with each other, and thus determines the best areas in terms of hydrocarbon accumulation and generation. Lithology of this formation determine by use of three methods includes of: Density- Neutron Cross plots, M-N plot, and MID plot, mainly reflects the predominance of porous limestone. From positive characteristic of reservoir in this field is low shale volume and high effective porosity. Formation permeability changes is very dramatically, and in terms of quality, the permeability is variable from Low – moderate in North west to high and good in South and central of field. From the perspective of hydrocarbon accumulation, the best part of the field located in North West. Because calculated hydrocarbons saturation increase to North West of the field to an average of 46 percent. In this part, oil- water contact becomes deeper and located at a depth of 127 meters from the top of the formation. In this part, the formation divided into 5 separate members, that the upper member is the best in terms of production. Producing zone in central and southern part of the field, is limited to ten meters below the Lafan cap rock.