A comparative analysis of pore geometry and structural technique versus conventional reservoir rock typing methods for characterizing a shallow marine carbonate reservoir in Sirte Basin-Libya

Title : A comparative analysis of pore geometry and structural technique versus conventional reservoir rock typing methods for characterizing a shallow marine carbonate reservoir in Sirte Basin-Libya

Abstract:

Accurate reservoir characterization is essential for the efficient development and management of hydrocarbon assets. While traditional rock typing methodologies, such as the Flow Zone Indicator (FZI) and Winland's R₃₅}, are commonly employed to predict reservoir properties, they often fail to fully account for the intricate complexity and heterogeneity of pore systems, particularly in carbonate reservoirs where diagenesis significantly alters pore structures. This study presents a comparative evaluation of the recently developed Pore Geometry and Structure (PGS) technique against the conventional FZI and Winland R35methods for characterizing a complex shallow marine limestone reservoir in the Sirte Basin, Libya.

The methodology involved collecting routine core analysis (RCAL) data (porosity and permeability) and thin-section petrography from two reservoir intervals. The PGS technique was applied by integrating petrographic observations with quantitative pore geometry parameters derived from Mercury Injection Capillary Pressure (MICP) data, classifying rock types based on the geometry and connectivity of the pore system. For comparison, the same core data were analyzed using the FZI method and the Winland R35method. Statistical correlation and regression analyses were performed to assess the predictive accuracy of each method against measured core permeability.

The results indicate that the PGS technique provides a significantly stronger correlation coefficient (R^{2} between predicted and measured permeability values compared to both the FZI and Winland R₃₅ methods. This superior performance suggests that the PGS approach more effectively captures the inherent heterogeneity and pore system connectivity, successfully distinguishing subtle variations in pore structures that were overlooked by conventional techniques. The consistency of PGS classifications with Special Core Analysis (SCAL) data further validated its reliability in these complex carbonate settings.

In conclusion, the study demonstrates that the Pore Geometry and Structure (PGS) technique offers a more robust framework for understanding the relationship between pore geometry and reservoir performance in shallow marine carbonate reservoirs of the Sirte Basin. Compared to traditional methods, PGS yields improved permeability prediction and a more realistic representation of reservoir heterogeneity, advocating for its adoption as a complementary, high-resolution tool. Future work will focus on integrating PGS-based rock types into dynamic reservoir models.

Keywords: Reservoir Characterization, Pore Geometry and Structure (PGS), Flow Zone Indicator (FZI), Winland R35}, Carbonate Reservoir, Sirte Basin, Permeability Prediction, Mercury Injection Capillary Pressure (MICP).

Biography:

Dr. Tarek S Duzan completed his MSc in Management from Robert Gordon University, Scotland, UK, in 2003, achieving an AGP of 3.7/4. In 2002, he earned a Postgraduate Diploma in Well and Field Management from the same university with an impressive AGP of 3.8/4. His academic journey also includes an Advanced English course and IELTS certification from UMST University, Manchester, UK, in 2001. Prior to this, in 1999, he pursued advanced courses in Petroleum Engineering at Al-Fateh University, Tripoli, Libya, achieving an AGP of 3.9/4. He began his academic career with a BSc in Petroleum Engineering from Tripoli (Al-Fateh) University, Tripoli, Libya, in 1994.