Laboratory Investigation of Determination of In-situ Fluid Saturation in the Fractured Carbonate Reservoir of Asmari Formation

Due to majority of relative permeability in reservoir engineering studies and its dependency to some physical properties, relative permeability measurement is the most complicated task in special core analysis studies. Equilibrium in front flow during flooding and recognizing the end effect capillary pressure in relative permeability tests is very important. For this reason the usage of in-situ saturation measurement methods has a paramount importance. Also performing SCAL tests in reservoir conditions and using reservoir oil creates correct and real data for reservoir engineers to apply in reservoir models. In this study, the goal of which is the determination of in-situ saturation during flooding in reservoir conditions, first four plug samples from Asmari formation were selected and thin section studies were done to recognize the lithologies and important features. Then using relative permeability apparatus in ambient condition, the average saturations of fluids in the cores were determined by measuring the volume of fluids expelled from the samples in the flooding test and the relative permeability curves were plotted. In the next step using x-ray relative permeability apparatus, the relative permeability experiments in the reservoir conditions were performed and the value of in-situ fluid saturation and the average saturation were determined via measuring the intensity of x-ray passes through the core. The results obtained from relative permeability tests in ambient and reservoir condition were then compared. Dead crude oil from Asmari formation has been used in all experiments.