Perpustakaan Digital ITB

Pore throat size distribution (PSD) is considered a fnger print for each rock type and has strong efects on many petrophysical parameters, so a comparative study was done on irregular subsurface rock samples that belong to Kareem and Rudeis Formations of middle and early Miocene, respectively. These samples were collected from San El-Hagar-1 well which is located to the East of the Nile Delta to show the efect of the diferent lithologies on pore throat size distribution and hence many related reservoir parameters such as displacement pressure, macroporosity, microporosity, mean hydraulic radius and permeability distribution function (PDF). For achieving the previous purpose, helium porosity and capillary pressure by mercury injection were carried out. Permeability measurements were canceled due to the non-cylindrical irregular nature of the tested samples. Porosity showed a great diference between the results of the samples of the two formations. Capillary pressure results showed the presence of characterized pore throat size distribution and hence capillary pressure-derived parameters for samples of each formation. PDF showed that samples of Kareem Fm. have better reservoir fow properties (permeability) in contrast to those of Rudeis Fm. which have tight reservoir fow properties. In addition, petrographical study through thin sections and scanning electron microscope displayed the presence of two facies which are feldspathic quartz wacke (sandstone facies) of Kareem Fm. and bioclastic sandy wackestone (calcareous facies) of Rudeis Fm. All results were consistent and confrmed the infuence of facies change on PSD and hence the reservoir parameters.