Quantitative Assessment of Heterogeneity Based on Lorenz Coefficient Values and Integrated Analysis of Petrophysical and Geological Data: Dariyan Formation, Central Persian Gulf

Hosseinzadeh, Mahnaz; Tavakoli, Vahid; Haghighat, Nooshafarin

doi:10.22071/gsj.2026.541451.2221

Quantitative Assessment of Heterogeneity Based on Lorenz Coefficient Values and Integrated Analysis of Petrophysical and Geological Data: Dariyan Formation, Central Persian Gulf

Articles in Press

Document Type : Original Research Paper

Authors

Mahnaz Hosseinzadeh ¹

Vahid Tavakoli ²

Nooshafarin Haghighat ³

¹ School of Geology, College of Science, University of Tehran

² University of Tehran

³ Geological Survey & Mineral Exploration of Iran, west branch (Shiraz)

10.22071/gsj.2026.541451.2221

Abstract

Heterogeneity in carbonate reservoirs is one of the key factors controlling reservoir quality and fluid flow. In this study, the heterogeneity of the Dariyan Formation in the Persian Gulf was evaluated using the Lorenz coefficient in combination with an integrated analysis of petrophysical and geological data. The study was conducted based on data from one well, incorporating quantitative interpretation of petrophysical logs, including gamma ray, bulk density, neutron porosity, sonic, and deep resistivity logs. In addition, 1093 thin sections from core samples were petrographically analyzed at the well scale to identify depositional facies, textures, microfacies characteristics, pore types, and dominant diagenetic processes. To quantitatively assess reservoir heterogeneity, the Lorenz coefficient was applied as a statistical index within depth intervals of 2 m. Lithological, textural, and facies-related heterogeneity in several intervals, shows a clear relationship with diagenetic trends. Increased heterogeneity is associated with reduction in average porosity and permeability, whereas diagenetic processes such as cementation and stylolitization locally reduce petrophysical heterogeneity.
The findings provide a more detailed quantitative insight into intra-reservoir heterogeneity in the Dariyan Formation and highlight the applicability of the Lorenz coefficient for characterizing heterogeneity in carbonate reservoirs, with implications for improved reservoir modeling and production strategy optimization.

Keywords

Heterogeneity

Lorenz coefficient

Darian Formation

Petrophysics

Carbonate reservoirs

Subjects