# Assessing reservoir heterogeneity using the turbulence factor as an effective tool for hydraulic flow unit classification for BM-85 Well, Gulf of Suez, Egypt

## TL;DR

This study uses the turbulence factor to classify hydraulic flow units in a heterogeneous reservoir in the Gulf of Suez, Egypt, improving understanding of fluid flow behavior.

## Contribution

The turbulence factor is introduced as a novel diagnostic tool for hydraulic flow unit classification in heterogeneous reservoirs.

## Key findings

- The turbulence factor (β) effectively identifies distinct hydraulic flow units in the BM-85 well reservoir.
- Reservoir heterogeneity is confirmed by a Dykstra–Parsons coefficient of 0.91 and wide permeability variation.
- High-quality flow units correlate with low β values and high permeability, while tight intervals show elevated β values.

## Abstract

Reservoir heterogeneity is crucial for predicting fluid flow behavior and improving hydrocarbon recovery in mature and complex reservoirs. This study investigates the heterogeneity of the Lower Senonian Formation in the BM-85 well, Gulf of Suez, Egypt, with a focus on classifying hydraulic flow units (HFUs) using the turbulence factor (β) as a key diagnostic parameter. Core data and well logs were used to predict some of pore throat parameters and porosity, respectively, which were integrated with turbulence factor calculations. Well-log interpretation, supported by litho-saturation crossplots, successfully delineated two pay zones. Pay 1 is characterized by moderate porosity (21%) and hydrocarbon saturation (63%), while Pay 2 exhibits excellent reservoir quality with an average permeability of 716.3 mD, effective porosity of 18–21%, and hydrocarbon saturation of 44%. Reservoir vertical and lateral heterogeneity is characterized using continuous, high-resolution downhole measurements. The wide permeability range, from 0.1 to 6431.82 mD, reflects strong reservoir heterogeneity and flow capacity. The Dykstra–Parsons coefficient (V = 0.91) confirmed extreme heterogeneity, indicative of pronounced contrasts in permeability and pore-throat distribution. The RQI–β cross-plot reveals the presence of two distinct hydraulic flow units within the studied reservoir interval, reflecting strong heterogeneity. High-quality flow units are associated with low β values and high permeability, whereas tight intervals show elevated β values and restricted flow behavior. The turbulence factor (β), calculated using the most recent empirical formulation, effectively captures non-Darcy flow effects and highlights subtle pore-system variations that are not resolved by conventional porosity–permeability relationships alone. These results demonstrate that incorporating β into HFU classification provides a more physically meaningful and robust framework for reservoir characterization, with direct implications for optimizing pay-zone identification and development strategies in the Gulf of Suez and other highly heterogeneous carbonate/clastic reservoirs.