Seismic Time Fractal Dimension for Characterizing Shajara Reservoirs of The Permo – Carboniferous Shajara Formation, Saudi Arabia

Volume 2 - Issue 1

Khalid Elyas Mohamed Elameen Alkhidir*

Received: July 18, 2018;   Published: July 26, 2018

DOI: 10.32474/MAOPS.2018.02.000128

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Abstract

The quality and assessment of a reservoir can be documented in detail by the demonstration of seismic time. This research aims to calculate fractal dimension from the relationship among seismic time, maximum seismic time and wetting phase saturation and to approve it by the fractal dimension derived from the relationship among capillary pressure and wetting phase saturation. In this research, porosity was measured on real collected sandstone samples and permeability was calculated theoretically from capillary pressure profile measured by mercury intrusion contaminating the pores of sandstone samples in consideration. Two equations for calculating the fractal dimensions have been employed. The first one defines the functional relationship between wetting phase saturation, seismic time, maximum seismic time and fractal dimension. The second equation involves to the wetting phase saturation as a function of capillary pressure and the fractal dimension. Two procedures for obtaining the fractal dimension have been utilized. The first procedure was done by plotting the logarithm of the ratio between seismic time and maximum seismic time versus logarithm wetting phase saturation. The slope of the first procedure = 3- Df (fractal dimension). The second procedure for obtaining the fractal dimension was determined by plotting the logarithm of capillary pressure versus the logarithm of wetting phase saturation. The slope of the second procedure = Df -3. Based on the obtained results of the fabricated stratigraphic column and the attained values of the fractal dimension, the sandstones of the Shajara reservoirs of the Shajara Formation were divided here into three units. The gained units from bottom to top are: Lower Shajara seismic time Fractal Dimension Unit, Middle Shajara seismic time Fractal dimension Unit, and Upper Shajara seismic time Fractal Dimension Unit. The results show similarity between seismic time fractal dimension and capillary pressure fractal dimension. It was also noted that samples with wide range of pore radius were characterized by high values of fractal dimensions due to an increase in their connectivities. In our case, and as conclusions the higher the fractal dimension, the higher the heterogeneity, the higher the permeability, the better the reservoir characteristics.

Abstract| Introduction| Materials and Methods| Results and Discussion| Conclusion| Acknowledgment| Introduction| References|