Quantitative impact of porosity and diagenesis on reservoir quality of the upper cretaceous, lidam formation in gialo oil field, Sirte Basin, NE Libya

Abstract EN

The paper discuses identifying of relationship of porosity and digenesis of the Lidam Carbonate Reservoir in 3V4-NC59E of Gialo Oil Field in Sirte Basin by means of well log data.

The date used for the evaluation of reservoir porosity, include wireline well logs data, as (Gamma ray, Porosity logs ( Sonic, Neutron and Density logs) and Resistivity logs, of well 3V4-NC59E, The logs analyzed every half foot for estimation Petrophysical characters of the Lidam Unit and then calculated as average every fife feet by FlexInLog Software , and plotted on Schlumberger Cross Plots, then correlated with thin section, core data report (routine data).

In this study, the indirect method was used to determine the porosity, by analyzing and interpreting the well logs and comparing them with the measurements of core samples and thin section (direct method), in addition to studying the impact of other petrophysical properties such as resistivity, permeability, volume of shale, mineral composition of the rock and the impact of diagenesis on the total porosity.The study proved that the results of the qualitative and quantitative interpretations of the indirect method in studying the porosity in the carbonate reservoir rocks are very close to the results of the direct method, and therefore it can be relied upon in study of the carbonate reservoir rocks within this basin.

fracturing have increased porosity, permeability and enhanced the reservoir quality of the Lidam Formation.